chore: cleanup dead code and update CLI docs

- Remove cmdThreadRunning dead code (CLI uses --status running now) - Remove step read from README (command not registered) - Update cli-reference.ts to reflect new four-layer commands Refs #463
Merge pull request 'feat: restructure CLI commands (workflow/thread/step/turn)' (#467 ) from fix/463-http-methods into main
2026-05-24 11:41:02 +00:00 · 2026-05-24 11:37:50 +00:00 · 2026-05-24 11:32:47 +00:00 · 2026-05-24 11:12:22 +00:00 · 2026-05-24 11:04:02 +00:00 · 2026-05-24 10:50:49 +00:00
141 changed files with 9765 additions and 1682 deletions
@@ -0,0 +1,67 @@
+# Sync README
+
+When updating README.md files in this monorepo, follow these conventions.
+
+## Scope
+
+- Root `README.md` — project overview and navigation hub
+- Per-package `packages/*/README.md` — each package self-contained
+
+## Root README Structure
+
+The root README should have these sections in order:
+
+1. **Title and one-liner** — stateless workflow engine driven by single-step CLI
+2. **Overview** — 2-3 paragraphs explaining what it does and key concepts
+3. **Architecture** — dependency layer diagram (text-based)
+4. **Packages** — table with ALL packages from packages/ directory, columns: Package, Description, Type (cli/lib/agent/app)
+5. **Quick Start** — install, build, register workflow, start thread, run step
+6. **CLI Reference** — brief command list, detailed usage in cli-workflow README
+7. **Development** — bun install / build / check / test
+
+## Per-Package README Structure
+
+Each package README should have:
+
+1. **Title** — package name
+2. **One-line description** — matching package.json
+3. **Overview** — what it does, where it sits in the architecture, dependencies
+4. **Installation** — bun add (for libs) or "included as binary" (for cli/agents)
+5. **API** (lib packages) — all exports from src/index.ts with type signatures, grouped by category, minimal usage examples
+6. **CLI Usage** (cli/agent packages) — command reference with examples
+7. **Internal Structure** — brief src/ file organization
+8. **Configuration** (if applicable)
+
+## Execution Steps
+
+### Step 1: Gather current state
+For each package read:
+- package.json (name, version, description, dependencies, bin)
+- src/index.ts (public API exports)
+- Existing README.md (preserve hand-written content worth keeping)
+
+### Step 2: Update root README
+- Ensure ALL packages in packages/ directory are listed in the table
+- Update CLI command reference from uwf --help output
+- Keep Quick Start examples valid
+
+### Step 3: Write/update each package README
+- Follow the per-package structure
+- API section MUST match actual src/index.ts exports — never invent
+- For agent packages: document CLI binary name, how it is invoked
+- For lib packages: document exported types and functions
+- Internal structure: list actual files in src/
+
+### Step 4: Verify
+- All relative links work
+- Package names match package.json
+- No references to removed/renamed packages
+- bun run build still passes
+
+## Guidelines
+
+- Only document what src/index.ts actually exports
+- Root README summarizes, package READMEs go into detail
+- Verify CLI examples against actual commands
+- Preserve existing good prose when updating
+- English for all README content
@@ -38,18 +38,26 @@ roles:
    capabilities:
      - coding
    procedure: |
-      Before starting any work, ensure a clean worktree:
-      1. `git checkout main && git pull` to get the latest code
-      2. `git checkout -b fix/<issue-number>-<short-description>` to create a fresh branch
-         - If bounced back from reviewer or tester, reuse the existing branch instead
+      IMPORTANT: Always work in a git worktree, NEVER modify the main working directory directly.
+
+      Before starting any work, set up an isolated worktree:
+      1. `cd ~/repos/workflow && git fetch origin` to get latest refs
+      2. First time (no existing branch):
+         - `git worktree add ~/repos/workflow-worktrees/fix/<issue-number>-<short-slug> -b fix/<issue-number>-<short-slug> origin/main`
+         - `cd ~/repos/workflow-worktrees/fix/<issue-number>-<short-slug> && bun install`
+      3. If bounced back from reviewer or tester (branch already exists):
+         - The worktree should already exist at `~/repos/workflow-worktrees/fix/<issue-number>-<short-slug>`
+         - `cd ~/repos/workflow-worktrees/fix/<issue-number>-<short-slug>`
+         - `git fetch origin && git rebase origin/main`
+      4. ALL subsequent work must happen inside the worktree directory.

      Then implement TDD:
-      3. Read the test spec from CAS: `uwf cas get <plan hash>` (find the hash from the latest planner step's frontmatter.plan)
-      4. If bounced back from reviewer or tester: read the previous role's output to understand what needs fixing
-      5. Write tests first based on the spec
-      6. Implement the code to make tests pass
-      7. Ensure `bun run build` passes with no errors
-      8. Run `bun test` to verify all tests pass
+      5. Read the test spec from CAS: `uwf cas get <plan hash>` (find the hash from the latest planner step's frontmatter.plan)
+      6. If bounced back from reviewer or tester: read the previous role's output to understand what needs fixing
+      7. Write tests first based on the spec
+      8. Implement the code to make tests pass
+      9. Ensure `bun run build` passes with no errors
+      10. Run `bun test` to verify all tests pass
    output: "List all files changed and provide a summary. Frontmatter must include: status (done or failed)."
    frontmatter:
      type: object
@@ -65,6 +73,8 @@ roles:
      - code-review
      - static-analysis
    procedure: |
+      First, cd into the worktree: `cd ~/repos/workflow-worktrees/fix/<issue-number>-*` (find the exact directory)
+
      Before reviewing, verify the git branch:
      1. Run `git branch --show-current` — confirm the branch name references the issue number being worked on
      2. If the branch doesn't correspond to the issue, flag it in your output and reject
@@ -98,6 +108,8 @@ roles:
    capabilities:
      - testing
    procedure: |
+      First, cd into the worktree: `cd ~/repos/workflow-worktrees/fix/<issue-number>-*` (find the exact directory)
+
      1. Run `bun test` for automated test verification
      2. Read the test spec from CAS: `uwf cas get <plan hash>` (find the hash from the latest planner step's frontmatter.plan)
      3. Verify each scenario in the spec is covered and passing
@@ -118,6 +130,8 @@ roles:
    goal: "You are a committer agent. You create a clean commit and push a PR linking the original issue."
    capabilities: []
    procedure: |
+      First, cd into the worktree: `cd ~/repos/workflow-worktrees/fix/<issue-number>-*` (find the exact directory)
+
      Note: You inherit the developer's worktree and branch. Do NOT create a new branch.
      1. Stage all changes: `git add -A`
      2. Commit with a descriptive message referencing the issue: `git commit -m "type: description\n\nFixes #N"`
@@ -125,6 +139,9 @@ roles:
         - If push hook fails: capture the error log in your output, mark hook_failed
      4. On push success: create a PR via `tea pr create --title "..." --description "..."`
         - PR description must follow the project template: What / Why / Changes / Ref sections, with `Fixes #N` in Ref
+      5. After PR creation, clean up the worktree:
+         - `cd ~/repos/workflow`
+         - `git worktree remove ~/repos/workflow-worktrees/fix/<issue-number>-<slug>`
    output: "Include PR URL on success or error log on failure. Frontmatter must include: success (true or false)."
    frontmatter:
      type: object
@@ -2,92 +2,102 @@

 A stateless workflow engine driven by a single-step CLI. Workflows are YAML definitions with roles, JSONata routing conditions, and a directed graph. Threads are immutable CAS-linked chains — each `uwf thread step` runs one moderator→agent→extract cycle and exits.

-## Package Map
+## Overview

-| Package | npm | Role |
-|---------|-----|------|
-| `cli-workflow` | `@uncaged/cli-workflow` | `uwf` CLI binary — thread lifecycle, workflow registry, CAS inspection, setup |
-| `workflow-protocol` | `@uncaged/workflow-protocol` | Shared TypeScript types (`WorkflowPayload`, `StepNodePayload`, `WorkflowConfig`, etc.) |
-| `workflow-moderator` | `@uncaged/workflow-moderator` | JSONata graph evaluator — determines next role or `$END` |
-| `workflow-agent-kit` | `@uncaged/workflow-agent-kit` | `createAgent` factory, context builder, two-layer extract pipeline |
-| `workflow-agent-hermes` | `@uncaged/workflow-agent-hermes` | `uwf-hermes` agent — spawns Hermes chat, captures session |
-| `workflow-util` | `@uncaged/workflow-util` | Crockford Base32, ULID, logger, frontmatter parsing |
+This monorepo implements **uwf**, a workflow engine with no long-running daemon. You register YAML workflow definitions in a content-addressed store (CAS), start a thread with an initial prompt, then invoke `uwf thread step` repeatedly until the moderator routes to `$END`. Each step is a complete process: the moderator evaluates JSONata conditions to pick the next role, an external agent CLI produces frontmatter markdown output, and an extract pipeline validates or structures that output against the role's JSON Schema.

-External: [`@uncaged/json-cas`](https://www.npmjs.com/package/@uncaged/json-cas) (CAS store + JSON Schema validation) + `@uncaged/json-cas-fs` (filesystem backend).
+Workflow state lives entirely on disk under `~/.uncaged/workflow/`: CAS nodes for definitions and step payloads, `registry.yaml` for workflow name→hash mappings, and `threads.yaml` for active thread head pointers. Completed threads are archived to `history.jsonl`. Because there is no server process, workflows are easy to debug, fork, and inspect with ordinary CLI tools.
+
+Agents are pluggable CLI binaries (`uwf-hermes`, `uwf-builtin`, `uwf-claude-code`, or custom commands). The engine spawns the configured agent with `<thread-id>` and `<role>`, sets `UWF_EDGE_PROMPT` from the graph transition, and captures both the agent's markdown output and a detail CAS node for session replay.
+
+## Architecture
+
+Dependency layers (lower layers have no dependency on higher layers):
+
+```
+Layer 0 — Contract
+  workflow-protocol          Shared types and JSON Schema definitions
+
+Layer 1 — Shared infra
+  workflow-util              Encoding, IDs, logging, frontmatter, paths
+  workflow-moderator         JSONata graph evaluator
+
+Layer 2 — Agent framework
+  workflow-agent-kit         createAgent factory, context builder, extract pipeline
+
+Layer 3 — Agent implementations
+  workflow-agent-hermes      Hermes ACP agent (uwf-hermes)
+  workflow-agent-builtin     Built-in LLM + tools agent (uwf-builtin)
+  workflow-agent-claude-code Claude Code agent (uwf-claude-code)
+
+Layer 4 — CLI
+  cli-workflow               uwf binary — thread lifecycle, registry, CAS, setup
+
+App (uses protocol; not in the runtime engine stack)
+  workflow-dashboard         Web UI for visual workflow editing
+```
+
+External CAS: [`@uncaged/json-cas`](https://www.npmjs.com/package/@uncaged/json-cas) (store API, hashing, schema validation) + `@uncaged/json-cas-fs` (filesystem backend).
+
+See [docs/architecture.md](docs/architecture.md) for the full design — three-phase engine loop, CAS node types, storage layout, agent CLI protocol, and design decisions.
+
+## Packages
+
+| Package | npm | Description | Type | README |
+|---------|-----|-------------|------|--------|
+| `cli-workflow` | `@uncaged/cli-workflow` | `uwf` CLI — thread lifecycle, workflow registry, CAS inspection, setup | cli | [README](packages/cli-workflow/README.md) |
+| `workflow-protocol` | `@uncaged/workflow-protocol` | Shared TypeScript types and JSON Schema constants | lib | [README](packages/workflow-protocol/README.md) |
+| `workflow-moderator` | `@uncaged/workflow-moderator` | JSONata graph evaluator — next role or `$END` | lib | [README](packages/workflow-moderator/README.md) |
+| `workflow-agent-kit` | `@uncaged/workflow-agent-kit` | `createAgent` factory, context builder, extract pipeline | lib | [README](packages/workflow-agent-kit/README.md) |
+| `workflow-util` | `@uncaged/workflow-util` | Crockford Base32, ULID, logger, frontmatter parsing, storage paths | lib | [README](packages/workflow-util/README.md) |
+| `workflow-agent-hermes` | `@uncaged/workflow-agent-hermes` | `uwf-hermes` — spawns Hermes chat via ACP | agent | [README](packages/workflow-agent-hermes/README.md) |
+| `workflow-agent-builtin` | `@uncaged/workflow-agent-builtin` | `uwf-builtin` — built-in LLM agent with file/shell tools | agent | [README](packages/workflow-agent-builtin/README.md) |
+| `workflow-agent-claude-code` | `@uncaged/workflow-agent-claude-code` | `uwf-claude-code` — spawns Claude Code CLI | agent | [README](packages/workflow-agent-claude-code/README.md) |
+| `workflow-dashboard` | `@uncaged/workflow-dashboard` | Web graph editor for workflow YAML (private, alpha) | app | [README](packages/workflow-dashboard/README.md) |

 ## Quick Start

 ```bash
-# 1. Configure provider and model
+# 1. Configure provider, model, and default agent
 uwf setup

 # 2. Register a workflow from YAML
 uwf workflow put examples/solve-issue.yaml

-# 3. Start a thread
+# 3. Start a thread (creates head pointer; does not execute)
 uwf thread start solve-issue -p "Fix the login redirect bug"

 # 4. Execute steps (one at a time, until done)
 uwf thread step <thread-id>
 ```

-## CLI Commands
+Use `-c, --count <number>` on `thread step` to run multiple steps in one invocation. Override the agent with `--agent <cmd>`.

-### Thread
+## CLI Reference

-| Command | Description |
-|---------|-------------|
-| `uwf thread start <workflow> -p <prompt>` | Create a thread (no execution) |
-| `uwf thread step <thread-id> [--agent <cmd>]` | Execute one moderator→agent→extract cycle |
-| `uwf thread show <thread-id>` | Show head pointer and done status |
-| `uwf thread list [--all]` | List threads (`--all` includes archived) |
-| `uwf thread steps <thread-id>` | List all steps chronologically |
-| `uwf thread read <thread-id> [--quota N]` | Render thread as readable markdown |
-| `uwf thread fork <step-hash>` | Fork from a specific step |
-| `uwf thread step-details <step-hash>` | Dump full detail node |
-| `uwf thread kill <thread-id>` | Terminate and archive |
+Global options: `-V, --version`, `--format <json|yaml>`, `-h, --help`.

-### Workflow
+| Group | Commands |
+|-------|----------|
+| **thread** | `start`, `step`, `show`, `list`, `kill`, `steps`, `read`, `fork`, `step-details` |
+| **workflow** | `put`, `show`, `list` |
+| **cas** | `get`, `put`, `put-text`, `has`, `refs`, `walk`, `reindex`, `schema list`, `schema get` |
+| **setup** | Interactive or `--provider`, `--base-url`, `--api-key`, `--model`, `--agent` |
+| **skill** | `cli` — print markdown reference of all uwf commands |
+| **log** | `list`, `show`, `clean` — process-level debug logs |

-| Command | Description |
-|---------|-------------|
-| `uwf workflow put <file.yaml>` | Register a workflow from YAML |
-| `uwf workflow show <name-or-hash>` | Show workflow definition |
-| `uwf workflow list` | List registered workflows |
+Config is stored in `~/.uncaged/workflow/config.yaml`. API keys go in `~/.uncaged/workflow/.env`.

-### CAS
-
-| Command | Description |
-|---------|-------------|
-| `uwf cas get <hash>` | Read a CAS node |
-| `uwf cas put <type-hash> <data>` | Store a node |
-| `uwf cas has <hash>` | Check existence |
-| `uwf cas refs <hash>` | List direct references |
-| `uwf cas walk <hash>` | Recursive traversal |
-| `uwf cas reindex` | Rebuild type index |
-| `uwf cas schema list` | List schemas |
-| `uwf cas schema get <hash>` | Show a schema |
-
-### Setup
-
-| Command | Description |
-|---------|-------------|
-| `uwf setup` | Interactive provider/model/agent configuration |
-| `uwf setup --provider ... --base-url ... --api-key ... --model ...` | Non-interactive setup |
-
-Config stored in `~/.uncaged/workflow/config.yaml`. API keys in `~/.uncaged/workflow/.env`.
+Detailed command usage, options, and examples: [packages/cli-workflow/README.md](packages/cli-workflow/README.md).

 ## Development

 ```bash
 bun install --no-cache     # Install dependencies
+bun run build              # tsc --build (all packages)
 bun run check              # tsc + biome + lint-log-tags
 bun run format             # Auto-format with Biome
 bun test                   # Run all tests
 ```

 Managed with **bun workspace**. See [CLAUDE.md](CLAUDE.md) for coding conventions.
-
-## Architecture
-
-See [docs/architecture.md](docs/architecture.md) for the full design — three-phase engine loop, CAS node types, storage layout, agent CLI protocol, and design decisions.
@@ -17,6 +17,15 @@
    "indentWidth": 2,
    "lineWidth": 100
  },
+  "css": {
+    "parser": {
+      "cssModules": true,
+      "tailwindDirectives": true
+    },
+    "linter": {
+      "enabled": false
+    }
+  },
  "javascript": {
    "formatter": {
      "quoteStyle": "double",
@@ -0,0 +1,779 @@
+# Built-in Role Agent 调研
+
+## 目标
+
+实现一个内置的 role agent（暂称 `uwf-builtin`），不依赖 hermes/openclaw 等外部 agent 进程。
+直接使用 workflow config 中配置的 model，自己实现 agent run loop 和关键 toolkit。
+
+---
+
+## 关键问题
+
+### Q1: Agent 接口协议
+
+现有 agent 是怎么被 CLI 调用的？输入（argv、环境变量）和输出（stdout、CAS）格式是什么？
+
+**调研要点：**
+- `cli-workflow` 里 `spawnAgent` 的完整实现
+- AgentConfig 类型定义
+- agent 进程的 exit code 约定
+- 环境变量传递（UWF_STORAGE_ROOT 等）
+
+**答案：**
+
+#### 调用链
+
+`uwf thread step` → `cmdThreadStepOnce` → moderator 求值下一 role → `resolveAgentConfig` → `spawnAgent`。
+
+#### AgentConfig 类型
+
+```146:149:packages/workflow-protocol/src/types.ts
+export type AgentConfig = {
+  command: string;
+  args: string[];
+};
+```
+
+在 `config.yaml` 的 `agents` 段注册，例如 `hermes: { command: "uwf-hermes", args: [] }`。
+
+#### spawnAgent 行为
+
+```627:653:packages/cli-workflow/src/commands/thread.ts
+function spawnAgent(agent: AgentConfig, threadId: ThreadId, role: string): CasRef {
+  const argv = [...agent.args, threadId, role];
+  let stdout: string;
+  try {
+    stdout = execFileSync(agent.command, argv, {
+      encoding: "utf8",
+      env: process.env,
+      stdio: ["ignore", "pipe", "pipe"],
+    });
+  } catch (e) {
+  // ... stderr 拼进 fail 消息
+  }
+
+  const line = stdout.trim().split("\n").pop()?.trim() ?? "";
+  if (!isCasRef(line)) {
+    fail(`agent stdout is not a valid CAS hash: ${line || "(empty)"}`);
+  }
+  return line;
+}
+```
+
+| 项目 | 约定 |
+|------|------|
+| **argv** | `[...agent.args, <thread-id>, <role>]`，即 `process.argv[2]`=threadId，`process.argv[3]`=role（与 `createAgent` 的 `parseArgv` 一致） |
+| **stdin** | 忽略 |
+| **stdout** | 纯文本，**最后一行**必须是新 `StepNode` 的 CAS hash（13 字符 Crockford Base32） |
+| **stderr** | 失败时 CLI 会附带 stderr；成功时无约定 |
+| **exit code** | `0` = 成功；非 0 时 `execFileSync` 抛错，step 失败 |
+| **环境变量** | 继承父进程 `process.env`（含 storage root、API key 等） |
+| **链头更新** | **不由 agent 负责**；agent 只写 CAS StepNode，CLI 在拿到 stdout hash 后更新 `threads.yaml` |
+
+Agent 解析优先级（`resolveAgentConfig`）：
+
+1. CLI `--agent` override（整段 command + args 字符串）
+2. `config.agentOverrides[workflow.name][role]`
+3. `config.defaultAgent`
+
+#### 环境变量：Storage Root
+
+文档中写的 `UWF_STORAGE_ROOT` **在当前代码中不存在**。实际优先级（`workflow-agent-kit` / `cli-workflow` 一致）：
+
+```33:43:packages/workflow-agent-kit/src/storage.ts
+export function resolveStorageRoot(): string {
+  const internal = process.env.UNCAGED_WORKFLOW_STORAGE_ROOT;
+  if (internal !== undefined && internal !== "") {
+    return internal;
+  }
+  const userOverride = process.env.WORKFLOW_STORAGE_ROOT;
+  if (userOverride !== undefined && userOverride !== "") {
+    return userOverride;
+  }
+  return getDefaultStorageRoot();
+}
+```
+
+Agent 子进程通过继承的 `process.env` 与父 CLI 共享同一 storage root；`createAgent` 内还会 `loadDotenv({ path: getEnvPath(storageRoot) })` 加载 `~/.uncaged/workflow/.env`。
+
+#### Agent 侧职责（设计文档 + 实现）
+
+- 读 `threads.yaml` 链头，构建 context，执行 role
+- 将 `StepNode` 写入 CAS（`output` / `detail` / `agent` / `prev` / `start`）
+- stdout 打印 step hash
+- **不**更新 `threads.yaml`
+
+---
+
+### Q2: createAgent 工厂
+
+workflow-agent-kit 的 `createAgent` 做了什么？它的完整生命周期是什么？
+
+**调研要点：**
+- `AgentOptions` 类型的 `run` 和 `continue` 回调签名
+- `AgentRunResult` 的完整定义
+- retry 逻辑（frontmatter 校验失败后的重试机制）
+- `persistStep` 写入 CAS 的 StepNode 结构
+
+**答案：**
+
+#### 类型定义
+
+```4:35:packages/workflow-agent-kit/src/types.ts
+export type AgentContext = ModeratorContext & {
+  threadId: ThreadId;
+  role: string;
+  store: Store;
+  workflow: WorkflowPayload;
+  outputFormatInstruction: string;
+};
+
+export type AgentRunResult = {
+  output: string;
+  detailHash: CasRef;
+  sessionId: string;
+};
+
+export type AgentContinueFn = (
+  sessionId: string,
+  message: string,
+  store: AgentContext["store"],
+) => Promise<AgentRunResult>;
+
+export type AgentRunFn = (ctx: AgentContext) => Promise<AgentRunResult>;
+
+export type AgentOptions = {
+  name: string;
+  run: AgentRunFn;
+  continue: AgentContinueFn;
+};
+```
+
+- **`run(ctx)`**：首次执行，返回原始 agent 文本 `output`、审计用 `detailHash`、用于续聊的 `sessionId`。
+- **`continue(sessionId, message, store)`**：在同一 session 上追加用户消息（用于 frontmatter 纠错），再次返回 `AgentRunResult`。
+
+`createAgent(options)` 返回 `() => Promise<void>`，作为 agent CLI 的 `main`（见 `uwf-hermes` 的 `cli.ts`）。
+
+#### 生命周期（按执行顺序）
+
+```101:152:packages/workflow-agent-kit/src/run.ts
+export function createAgent(options: AgentOptions): () => Promise<void> {
+  return async function main(): Promise<void> {
+    const { threadId, role } = parseArgv(process.argv);
+    const storageRoot = resolveStorageRoot();
+    loadDotenv({ path: getEnvPath(storageRoot) });
+
+    const ctx = await buildContextWithMeta(threadId, role);
+    // 1. 校验 role 存在
+    // 2. 从 CAS 取 frontmatter JSON Schema → buildOutputFormatInstruction → ctx.outputFormatInstruction
+
+    let agentResult = await options.run(ctx);
+
+    let outputHash = await tryExtractOutput(agentResult.output, roleDef.frontmatter, ctx);
+
+    for (let retry = 0; retry < MAX_FRONTMATTER_RETRIES && outputHash === null; retry++) {
+      const correctionMessage = "Your previous response did not contain valid YAML frontmatter...";
+      agentResult = await options.continue(agentResult.sessionId, correctionMessage, ctx.meta.store);
+      outputHash = await tryExtractOutput(agentResult.output, roleDef.frontmatter, ctx);
+    }
+
+    if (outputHash === null) { fail(...); }
+
+    const stepHash = await persistStep({ ctx, outputHash, detailHash: agentResult.detailHash, agentName });
+    process.stdout.write(`${stepHash}\n`);
+  };
+}
+```
+
+| 阶段 | 行为 |
+|------|------|
+| 解析 argv | `argv[2]=threadId`, `argv[3]=role`，缺失则 `stderr` + `exit(1)` |
+| Context | `buildContextWithMeta` + 可选 `outputFormatInstruction` |
+| Run | `options.run(ctx)` |
+| Extract | **仅** `tryFrontmatterFastPath`（见 Q4）；**不**调用 `extract()` LLM fallback |
+| Retry | 最多 `MAX_FRONTMATTER_RETRIES = 2` 次 `continue` + 再试 fast-path |
+| Persist | `persistStep` → `writeStepNode` |
+| 输出 | stdout 一行 step CAS hash |
+
+#### StepNode 写入结构
+
+```44:68:packages/workflow-agent-kit/src/run.ts
+async function writeStepNode(options: {
+  store: AgentStore["store"];
+  schemas: AgentStore["schemas"];
+  startHash: CasRef;
+  prevHash: CasRef | null;
+  role: string;
+  outputHash: CasRef;
+  detailHash: CasRef;
+  agentName: string;
+}): Promise<CasRef> {
+  const payload: StepNodePayload = {
+    start: options.startHash,
+    prev: options.prevHash,
+    role: options.role,
+    output: options.outputHash,
+    detail: options.detailHash,
+    agent: options.agentName,
+  };
+  // store.put(stepNode schema) + validate
+}
+```
+
+`agentName` 经 `agentLabel(name)` 规范化：已有 `uwf-` 前缀则原样，否则加 `uwf-`（如 `hermes` → `uwf-hermes`）。
+
+`prevHash`：若链头仍是 `StartNode` 则为 `null`，否则为当前 head step hash。
+
+---
+
+### Q3: Context Builder
+
+`buildContextWithMeta` 构建了什么上下文给 agent？
+
+**调研要点：**
+- `AgentContext` 完整类型定义（所有字段）
+- context 构建过程（CAS chain walk）
+- `outputFormatInstruction` 怎么生成的
+- role definition 怎么获取（从 workflow YAML）
+
+**答案：**
+
+#### AgentContext 字段
+
+继承 `ModeratorContext`：
+
+```60:68:packages/workflow-protocol/src/types.ts
+export type ModeratorContext = {
+  start: StartNodePayload;
+  steps: StepContext[];
+};
+```
+
+```48:51:packages/workflow-protocol/src/types.ts
+export type StartNodePayload = {
+  workflow: CasRef;
+  prompt: string;
+};
+```
+
+```61:63:packages/workflow-protocol/src/types.ts
+export type StepContext = Omit<StepRecord, "output"> & {
+  output: unknown;
+};
+```
+
+`AgentContext` 额外字段：
+
+| 字段 | 类型 | 含义 |
+|------|------|------|
+| `threadId` | `ThreadId` | 当前线程 |
+| `role` | `string` | 本步要执行的角色名 |
+| `store` | `Store` | CAS store（读写节点） |
+| `workflow` | `WorkflowPayload` | 已从 CAS 加载的 workflow 定义 |
+| `outputFormatInstruction` | `string` | 由 `createAgent` 根据 role 的 frontmatter schema 生成；`buildContext*` 初始为 `""` |
+
+`buildContextWithMeta` 还返回 `meta`：
+
+```148:154:packages/workflow-agent-kit/src/context.ts
+export type BuildContextMeta = {
+  storageRoot: string;
+  store: Store;
+  schemas: AgentStore["schemas"];
+  headHash: CasRef;
+  chain: ChainState;
+};
+```
+
+#### CAS chain walk
+
+1. 从 `threads.yaml[threadId]` 取 `headHash`
+2. `walkChain`：若 head 是 `StartNode`，`stepsNewestFirst=[]`；否则沿 `prev` 收集所有 `StepNode`， newest-first
+3. `buildHistory`：反转为时间序，`expandOutput` 把每步 `output` CasRef 展开为 JSON payload（供 prompt / JSONata 使用）
+4. `loadWorkflow`：从 `start.workflow` CasRef 加载 `WorkflowPayload`
+
+#### Role definition 来源
+
+- 作者写在 workflow YAML 的 `roles.<name>`（`goal`, `capabilities`, `procedure`, `output`, `frontmatter` 等）
+- `uwf workflow put` 时 `frontmatter` 内联 JSON Schema 经 `putSchema` 存入 CAS，workflow 里存的是 **CasRef**
+- Agent 运行时：`ctx.workflow.roles[ctx.role]` → `RoleDefinition`
+
+#### outputFormatInstruction
+
+在 `createAgent` 中，若 `getSchema(store, roleDef.frontmatter)` 非空，则：
+
+```typescript
+ctx.outputFormatInstruction = buildOutputFormatInstruction(frontmatterSchema);
+```
+
+`buildOutputFormatInstruction` 根据 JSON Schema 的 `properties` 生成「必须以 `---` YAML frontmatter 开头」的说明和示例字段列表（见 `build-output-format-instruction.ts`）。
+
+各 agent 实现（Hermes / Claude Code）在组装 prompt 时把该块放在最前，再接 `buildRolePrompt(roleDef)`。
+
+---
+
+### Q4: Extract Pipeline
+
+agent 输出怎么被处理成结构化数据？
+
+**调研要点：**
+- frontmatter fast-path 的完整逻辑
+- LLM extract fallback 的实现（`extract.ts`）
+- frontmatter schema 从哪里来（role 定义里的 `frontmatter` 字段）
+- 校验失败时的 correction prompt 是什么
+
+**答案：**
+
+#### Schema 来源
+
+Workflow YAML 中每个 role 的 `frontmatter:` 段是 JSON Schema 对象；注册时：
+
+```66:76:packages/cli-workflow/src/commands/workflow.ts
+async function resolveFrontmatterRef(..., frontmatter: unknown): Promise<CasRef> {
+  // 校验为 JSON Schema → putSchema → 返回 CasRef
+}
+```
+
+运行时 `roleDef.frontmatter` 即该 schema 的 CAS hash；structured `output` 节点用**同一 schema** 写入 CAS。
+
+#### Frontmatter fast-path（createAgent 实际使用的路径）
+
+```148:195:packages/workflow-agent-kit/src/frontmatter.ts
+export async function tryFrontmatterFastPath(
+  raw: string,
+  outputSchema: CasRef,
+  store: Store,
+): Promise<FrontmatterFastPathResult | null>
+```
+
+流程：
+
+1. `parseFrontmatterMarkdown(raw)` → 标准 agent 字段（`status`, `next`, `confidence`, `artifacts`, `scope`）+ body
+2. `validateFrontmatter` 失败 → `null`
+3. `getSchema(store, outputSchema)` + `extractSchemaFields` 得到 role 需要的属性名
+4. `buildCandidate`：从标准 frontmatter + YAML 原始字段拼出符合 schema 的对象
+5. `store.put(outputSchema, candidate)` + `validate` → 成功则 `{ body, outputHash }`
+
+**永不抛错**，失败返回 `null`。
+
+#### LLM extract fallback（已实现但未接入 createAgent）
+
+```135:181:packages/workflow-agent-kit/src/extract.ts
+export async function extract(
+  rawOutput: string,
+  outputSchema: CasRef,
+  config: WorkflowConfig,
+): Promise<ExtractResult>
+```
+
+- 模型：`resolveExtractModelAlias(config)` → `modelOverrides.extract` → `models.extract` → `models.default` → `defaultModel`
+- HTTP：`POST {baseUrl}/chat/completions`，`response_format: { type: "json_object" }`
+- System：要求按 JSON Schema 从 agent 输出提取单个 JSON 对象
+- 校验通过后 `store.put(outputSchema, structured)`
+
+**重要：`createAgent` 当前未调用 `extract()`**。fast-path 失败且 2 次 `continue` 仍失败则直接 `fail()`。builtin agent 若希望无 frontmatter 也能跑，需在 kit 或 builtin 层显式接入 `extract()`。
+
+#### Correction prompt（retry）
+
+```125:128:packages/workflow-agent-kit/src/run.ts
+const correctionMessage =
+  "Your previous response did not contain valid YAML frontmatter matching the role schema.\n" +
+  "You MUST begin your response with a YAML frontmatter block (--- delimited).\n" +
+  "Please output ONLY the corrected frontmatter block followed by your work.";
+```
+
+通过 `options.continue(sessionId, correctionMessage, store)` 发给外部 agent；builtin 需在自有 message 历史里 append 同等语义的 user 消息。
+
+---
+
+### Q5: Model 配置与 LLM 调用
+
+workflow 怎么配置和使用 model？
+
+**调研要点：**
+- `WorkflowConfig` 中 providers/models/defaultModel/modelOverrides 的完整定义
+- `resolveModel` 函数的实现
+- `chatCompletionText` 的实现（OpenAI 兼容 HTTP 客户端）
+- 有没有 streaming 支持？tool calling 支持？
+
+**答案：**
+
+#### WorkflowConfig
+
+```136:160:packages/workflow-protocol/src/types.ts
+export type ProviderConfig = {
+  baseUrl: string;
+  apiKeyEnv: string;
+};
+
+export type ModelConfig = {
+  provider: ProviderAlias;
+  name: string;
+};
+
+export type WorkflowConfig = {
+  providers: Record<ProviderAlias, ProviderConfig>;
+  models: Record<ModelAlias, ModelConfig>;
+  agents: Record<AgentAlias, AgentConfig>;
+  defaultAgent: AgentAlias;
+  agentOverrides: Record<WorkflowName, Record<RoleName, AgentAlias>> | null;
+  defaultModel: ModelAlias;
+  modelOverrides: Record<Scenario, ModelAlias> | null;
+};
+```
+
+示例见 `docs/architecture.md`（`providers` / `models` / `defaultModel` / `modelOverrides.extract`）。
+
+#### resolveModel
+
+```32:50:packages/workflow-agent-kit/src/extract.ts
+export function resolveModel(config: WorkflowConfig, alias: ModelAlias): ResolvedLlmProvider {
+  const modelEntry = config.models[alias];
+  const providerEntry = config.providers[modelEntry.provider];
+  const apiKey = process.env[providerEntry.apiKeyEnv];
+  return { baseUrl: providerEntry.baseUrl, apiKey, model: modelEntry.name };
+}
+```
+
+`ResolvedLlmProvider = { baseUrl, apiKey, model }`。
+
+Extract 专用别名解析：
+
+```18:30:packages/workflow-agent-kit/src/extract.ts
+export function resolveExtractModelAlias(config: WorkflowConfig): ModelAlias {
+  return config.modelOverrides?.extract ?? (config.models.extract ? "extract" : config.models.default ? "default" : config.defaultModel);
+}
+```
+
+**尚无** `modelOverrides` 按 role/workflow 解析 agent 主模型的函数；builtin 首版可用 `config.defaultModel`，扩展时可加 `modelOverrides.agent` 或与 `agentOverrides` 对称的表。
+
+#### chatCompletionText
+
+```87:124:packages/workflow-agent-kit/src/extract.ts
+async function chatCompletionText(
+  provider: ResolvedLlmProvider,
+  messages: Array<{ role: "system" | "user"; content: string }>,
+): Promise<string>
+```
+
+| 能力 | 现状 |
+|------|------|
+| 协议 | OpenAI 兼容 `POST /chat/completions` |
+| Streaming | **无**（一次性 `response.text()`） |
+| Tool calling | **无**（无 `tools` / `tool_calls` 字段） |
+| 多模态 | **无**（仅 text `content`） |
+| Extract 专用 | `response_format: { type: "json_object" }` |
+
+builtin agent 的 run loop 需要**新写**带 `tools` 的 completion 客户端（可放在 `workflow-agent-builtin` 或扩展 `workflow-agent-kit` 的 `llm/` 模块），不能复用当前 `chatCompletionText` 而不改。
+
+---
+
+### Q6: Hermes Agent 参考实现
+
+`uwf-hermes` 是怎么实现 `run` 和 `continue` 的？
+
+**调研要点：**
+- prompt 怎么组装的（outputFormatInstruction + rolePrompt + task + history）
+- hermes CLI 的调用参数
+- session management（resume）
+- 输出怎么捕获
+
+**答案：**
+
+#### Prompt 组装
+
+```40:53:packages/workflow-agent-hermes/src/hermes.ts
+export function buildHermesPrompt(ctx: AgentContext): string {
+  const roleDef = ctx.workflow.roles[ctx.role];
+  const rolePrompt = roleDef !== undefined ? buildRolePrompt(roleDef) : "";
+  const parts: string[] = [];
+  if (ctx.outputFormatInstruction !== "") {
+    parts.push(ctx.outputFormatInstruction, "");
+  }
+  parts.push(rolePrompt, "", "## Task", ctx.start.prompt);
+  const historyBlock = buildHistorySummary(ctx.steps);
+  if (historyBlock !== "") {
+    parts.push("", historyBlock);
+  }
+  return parts.join("\n");
+}
+```
+
+`buildRolePrompt` 生成 `## Goal` / `## Capabilities` / `## Prepare`（含 `generateCliReference()`）/ `## Procedure` / `## Output`。
+
+`buildHistorySummary`：每步 `role`、`JSON.stringify(step.output)`、`agent`。
+
+Hermes 把**整段 prompt 作为单条 user 消息**传给 `hermes chat -q`（无独立 system channel）。
+
+#### Hermes CLI 参数
+
+首次：
+
+```88:97:packages/workflow-agent-hermes/src/hermes.ts
+spawnHermes(["chat", "-q", prompt, "--yolo", "--max-turns", "90", "--quiet"]);
+```
+
+续聊：
+
+```100:114:packages/workflow-agent-hermes/src/hermes.ts
+spawnHermes(["chat", "--resume", sessionId, "-q", message, "--yolo", "--max-turns", "90", "--quiet"]);
+```
+
+#### Session
+
+- stdout/stderr 中解析 `session_id: <id>`（`parseSessionIdFromStdout`）
+- 会话文件：`~/.hermes/sessions/session_<id>.json`
+- `loadHermesSession` → `storeHermesSessionDetail`：每 assistant/tool 消息写成 CAS turn 节点，汇总为 `detail`；**output 文本** = 最后一条非空 `assistant` 的 `content`
+
+#### 与 createAgent 的衔接
+
+```157:164:packages/workflow-agent-hermes/src/hermes.ts
+export function createHermesAgent(): () => Promise<void> {
+  return createAgent({ name: "hermes", run: runHermes, continue: continueHermes });
+}
+```
+
+`uwf-hermes` 入口：`createHermesAgent()` 即 main。
+
+Claude Code 包（`workflow-agent-claude-code`）结构相同：`buildClaudeCodePrompt` 同构，`claude -p` + `--resume` + JSON stdout 解析。
+
+---
+
+### Q7: Toolkit 需求分析
+
+要实现一个自给自足的 agent，最少需要哪些 tool？
+
+**调研要点：**
+- 现有 workflow example（solve-issue.yaml）里 role 都做什么任务
+- hermes agent 在 workflow 场景下常用哪些 tool
+- 哪些 tool 是 agent loop 必须的（如 file read/write、shell exec、web fetch）
+
+**答案：**
+
+#### solve-issue.yaml 角色能力
+
+| Role | capabilities | 隐含需求 |
+|------|----------------|----------|
+| planner | issue-analysis, planning | 读上下文/仓库、总结，通常不需写代码 |
+| developer | file-edit, shell, testing | **读文件、写文件、执行命令** |
+| reviewer | code-review, static-analysis | 读 diff/文件、静态分析（可读+可选 shell） |
+
+#### Hermes 侧
+
+Hermes 自带完整 agent runtime（`--yolo`、max-turns），tool 集由 Hermes 项目定义，workflow 不配置。从 session JSON 可见 `tool_calls` 被记入 detail，常见包括文件与 shell 类工具。
+
+#### Builtin 最小 toolkit 建议
+
+| 优先级 | Tool | 用途 |
+|--------|------|------|
+| P0 | `read_file` | 读仓库/配置/issue 上下文 |
+| P0 | `write_file` / `edit_file` | developer 改代码 |
+| P0 | `run_command` | 测试、构建、git（需 cwd + timeout + 输出截断） |
+| P1 | `list_dir` / `glob` | 导航代码库 |
+| P1 | `grep` | 搜索符号/引用 |
+| P2 | `fetch_url` | 查文档（planner 偶尔需要） |
+
+**不需要**在 builtin 里实现 moderator / workflow 路由工具——仍由 `uwf thread step` + JSONata 负责。
+
+#### Agent loop 必须能力
+
+1. 多轮 LLM 调用 + **OpenAI-style tool_calls** 解析与执行
+2. 将 tool 结果 append 回 messages
+3. 终止条件：模型不再请求 tool，或达到 `maxTurns`
+4. 最终响应须含合法 YAML frontmatter（满足 Q4），供 `createAgent` fast-path
+
+---
+
+## 方案草案
+
+（调研完成后基于以上答案撰写）
+
+### 架构设计
+
+```mermaid
+flowchart TB
+  subgraph cli ["cli-workflow"]
+    Step["uwf thread step"]
+    Spawn["spawnAgent(uwf-builtin, threadId, role)"]
+    Step --> Spawn
+  end
+
+  subgraph builtin_pkg ["@uncaged/workflow-agent-builtin"]
+    Main["createBuiltinAgent() = createAgent({...})"]
+    Prompt["buildBuiltinPrompt(ctx)"]
+    Loop["runBuiltinLoop(provider, messages, tools)"]
+    Tools["Toolkit: read/write/exec/..."]
+    Detail["storeBuiltinDetail(turns)"]
+    Main --> Prompt
+    Main --> Loop
+    Loop --> Tools
+    Loop --> Detail
+  end
+
+  subgraph kit ["workflow-agent-kit"]
+    Ctx["buildContextWithMeta"]
+    FM["tryFrontmatterFastPath"]
+    Persist["persistStep"]
+    Ctx --> Main
+    Main --> FM
+    FM --> Persist
+  end
+
+  subgraph cas ["CAS / config"]
+    Config["config.yaml models/providers"]
+    CAS["cas/ + threads.yaml"]
+  end
+
+  Spawn --> Main
+  Config --> Loop
+  CAS --> Ctx
+  Persist --> CAS
+  Spawn -->|"stdout: step hash"| Step
+```
+
+**新包**：`packages/workflow-agent-builtin`，bin `uwf-builtin`，仅依赖 `workflow-agent-kit`、`workflow-protocol`、`workflow-util`（可选 `@uncaged/json-cas` 写 detail schema）。
+
+**分层**：
+
+| 层 | 职责 |
+|----|------|
+| `createAgent`（kit） | argv、context、frontmatter extract、StepNode、stdout 协议 — **不变** |
+| `builtin/agent.ts` | `run` / `continue` 实现 |
+| `builtin/llm.ts` | OpenAI 兼容 chat + tools（可后续抽到 kit） |
+| `builtin/tools/*.ts` | 各 tool 的 JSON Schema + handler |
+| `builtin/prompt.ts` | 复用 Hermes 的 prompt 拼接逻辑（或抽到 kit 的 `buildAgentPrompt`） |
+| `builtin/detail.ts` | 类似 Hermes：每轮 assistant/tool 写入 CAS detail |
+
+**配置集成**：
+
+```yaml
+agents:
+  builtin:
+    command: "uwf-builtin"
+    args: []
+defaultAgent: "builtin"   # 或 agentOverrides 按 role 指定
+```
+
+模型：首版 `resolveModel(config, config.defaultModel)`；后续可增加 `modelOverrides.agent` 或 per-role 映射。
+
+---
+
+### Agent Run Loop
+
+伪代码（单次 `run(ctx)`）：
+
+```
+1. provider ← resolveModel(loadWorkflowConfig(), defaultModel)
+2. system ← buildBuiltinPrompt(ctx)   // outputFormatInstruction + buildRolePrompt + Task + History
+3. messages ← [{ role: "system", content: system }]
+4. sessionId ← newULID()              // 内存或临时目录，供 continue 使用
+5. turns ← []
+
+6. for turn in 1..MAX_TURNS:
+     response ← chatCompletionWithTools(provider, messages, TOOL_DEFINITIONS)
+     record assistant message + tool_calls in turns
+
+     if response has no tool_calls:
+       finalText ← response.content
+       break
+
+     for each tool_call:
+       result ← executeTool(tool_call, { cwd: process.cwd() })
+       messages.push tool result
+       record in turns
+
+7. if no finalText with valid frontmatter after loop:
+     optionally one-shot "finalize" message without tools
+
+8. detailHash ← storeBuiltinDetail(store, sessionId, turns, metadata)
+9. return { output: finalText, detailHash, sessionId }
+```
+
+**`continue(sessionId, message, store)`**：
+
+- 从内存/磁盘恢复 `messages` + `turns`
+- `messages.push({ role: "user", content: message })`（correction 或续聊）
+- 从步骤 6 继续，步数上限可单独设小一点（如 3）
+- 返回新的 `AgentRunResult`
+
+**与 frontmatter 的配合**：
+
+- system prompt 已含 `outputFormatInstruction`；最后一轮可强制 user：`Now output your final answer with YAML frontmatter only if you have not yet.`
+- 仍依赖 `createAgent` 的 fast-path + 最多 2 次 continue
+
+**安全**：
+
+- `run_command`：白名单或需 `UWF_BUILTIN_ALLOW_SHELL=1`，默认工作区限定在 `process.cwd()` 或 `start` 中将来扩展的 `workspace` 字段
+- 路径：禁止 `..` 逃逸出 workspace root
+
+---
+
+### Toolkit 设计
+
+统一注册表：
+
+```typescript
+type BuiltinTool = {
+  name: string;
+  description: string;
+  parameters: JSONSchema; // object type
+  execute: (args: unknown, ctx: ToolContext) => Promise<string>;
+};
+
+type ToolContext = {
+  cwd: string;
+  storageRoot: string;
+};
+```
+
+| Tool name | OpenAI function | 行为摘要 |
+|-----------|-----------------|----------|
+| `read_file` | `read_file` | `{ path }` → UTF-8 文本，大小上限 |
+| `write_file` | `write_file` | `{ path, content }` → 写盘，返回确认 |
+| `edit_file` | 可选 | search/replace 块，减少 token |
+| `run_command` | `run_command` | `{ command, cwd? }` → stdout/stderr 截断 |
+| `list_dir` | `list_dir` | `{ path }` → 条目列表 |
+| `grep` | `grep` | `{ pattern, path? }` → 匹配行 |
+
+**LLM 请求形状**（扩展 extract 客户端）：
+
+```json
+{
+  "model": "...",
+  "messages": [...],
+  "tools": [{ "type": "function", "function": { "name", "description", "parameters" } }],
+  "tool_choice": "auto"
+}
+```
+
+解析 `choices[0].message.tool_calls`，执行后以 `{ role: "tool", tool_call_id, content }` 回传。
+
+**不提供** streaming 首版；detail CAS 记录每轮 tool 名/参数/结果摘要供 `uwf thread step-details` 调试。
+
+---
+
+### 与现有架构的集成
+
+| 集成点 | 方式 |
+|--------|------|
+| CLI 协议 | 实现标准 agent CLI：`uwf-builtin <thread-id> <role>`，stdout 一行 step hash，exit 0/1 |
+| 工厂 | `export function createBuiltinAgent()` → `createAgent({ name: "builtin", run, continue })` |
+| Context / Prompt | 复用 `buildContextWithMeta`、`buildRolePrompt`、`buildOutputFormatInstruction`；prompt 布局对齐 `buildHermesPrompt` |
+| 结构化输出 | 优先 YAML frontmatter fast-path；可选后续在 `createAgent` 增加 `extract()` fallback 开关 |
+| 配置 | `config.yaml` 增加 `agents.builtin`；`uwf setup` 可选默认 agent |
+| 存储 | `resolveStorageRoot()` + `loadWorkflowConfig` + `getEnvPath`；与 Hermes 相同，**不**改 `threads.yaml` 写入方 |
+| 测试 | 单元测试：tool handlers、prompt 组装、mock LLM tool loop；集成测试：临时 storage root + fake provider |
+| 发布 | 新包 `@uncaged/workflow-agent-builtin`，bin `uwf-builtin`，加入 `scripts/publish-all.mjs` |
+
+**明确不做**：
+
+- 不替代 moderator / 不在 agent 内调用 `uwf thread step`
+- 不依赖 Hermes/OpenClaw/Claude Code 二进制
+- 首版不实现 streaming、不实现 MCP
+
+**建议实现顺序**：
+
+1. `llm.ts`：tool calling HTTP 客户端 + 单测
+2. P0 tools + `runBuiltinLoop`
+3. `createBuiltinAgent` + detail CAS
+4. `config` / docs / `examples` 可选 `agentOverrides` 演示
+5. （可选）`createAgent` 接入 `extract()` fallback
@@ -0,0 +1,73 @@
+# Issue #418: ACP session/resume 返回空文本
+
+## 调研日期: 2026-05-23
+
+## 根因
+
+`session/resume` 在 restore 路径下 `_make_agent()` 失败，异常被静默吞掉。
+
+### 完整调用链
+
+```
+resume_session(sid)
+  → update_cwd(sid)
+    → get_session(sid) → _restore(sid)
+      → _make_agent()
+        → resolve_runtime_provider("custom") 失败（line 548-561）
+        → AIAgent() 抛出 "No LLM provider configured"（line 564）
+      → except Exception 静默吞掉（line 482-484）→ return None
+    → return None
+  → state is None → fallback: create_session()（新 sid，无历史）
+```
+
+### 关键代码位置（acp_adapter/session.py）
+
+- `_restore()` line 426-498: 从 DB 恢复 session，但 except 太宽泛
+- `_make_agent()` line 520-568: provider 解析在 restore 路径下不完整
+- Line 548-561: `resolve_runtime_provider("custom")` 失败后，`base_url` 虽然从 DB 取到了但没传给 AIAgent
+
+### 实测行为
+
+1. Phase 1: `session/new` + `prompt` → 正常，有 `agent_message_chunk`
+2. Phase 2: `session/resume` + `prompt`
+   - resume 返回成功，但 `available_commands_update` 里 sessionId 是新的（create_session fallback）
+   - 用原始 sid 发 prompt → `stopReason: "refusal"`（session 不在内存中）
+   - 用新 sid 发 prompt → 能跑但无历史（agent 回答"不知道 secret code"）
+
+### 验证脚本
+
+```python
+# 直接调用 _restore 验证
+cd ~/.hermes/hermes-agent
+python3 -c "
+import sys; sys.path.insert(0, '.')
+from acp_adapter.session import SessionManager
+sm = SessionManager()
+result = sm._restore('SESSION_ID_HERE')
+print(result)  # None — _make_agent 抛异常被吞掉
+"
+```
+
+### 两个 bug
+
+1. **`_make_agent` provider fallback 不完整**: restore 时 DB 里有 `base_url` 和 `api_mode`，但 `resolve_runtime_provider` 失败后这些值没被正确传递给 AIAgent
+2. **`_restore` 的 except 太宽泛**: 静默吞掉所有异常，连 warning 都只在 debug 级别，导致 resume 失败完全无感知
+
+### Hermes 版本
+
+- v0.10.0 (2026.4.16) — 初始测试
+- v0.14.0 (2026.5.16) — 更新后重新测试，bug 仍在
+- 代码路径: ~/.hermes/hermes-agent/acp_adapter/session.py
+
+### v0.14.0 测试结果 (2026-05-23)
+
+- `_restore` 仍因 `custom` provider 解析失败返回 None
+- 日志更清晰了：`WARNING: Failed to recreate agent for ACP session ...`
+- resume fallback 创建新 session（新 sid），但 agent 居然能回答之前的问题（可能通过 memory/session search）
+- 核心问题不变：sessionId 变了，client 用旧 sid 发 prompt → refusal
+
+### 上游 Issue
+
+- https://github.com/NousResearch/hermes-agent/issues/13489 — 已评论根因分析
+- https://github.com/NousResearch/hermes-agent/issues/8083 — resume 静默创建新 session
+- https://github.com/NousResearch/hermes-agent/issues/18452 — _make_agent fallback 不完整
@@ -0,0 +1,77 @@
+name: "debate"
+description: "Structured debate between two sides. Tests cross-process session resume."
+roles:
+  against:
+    description: "Argues against the proposition"
+    goal: |
+      You are a skilled debater arguing AGAINST the proposition.
+      Be logical, cite evidence, and directly address your opponent's points.
+      Keep each argument concise (under 200 words).
+    capabilities:
+      - argumentation
+      - critical-thinking
+    procedure: |
+      1. If this is the opening, present your strongest argument against the proposition.
+      2. If responding to the other side, directly counter their points with evidence and logic.
+      3. If you find yourself genuinely convinced by the other side, you may concede.
+    output: |
+      Provide your argument in the frontmatter.
+      Set conceded to true ONLY if you are genuinely convinced and wish to stop debating.
+    frontmatter:
+      type: object
+      properties:
+        argument:
+          type: string
+        conceded:
+          type: boolean
+      required: [argument, conceded]
+  for:
+    description: "Argues for the proposition"
+    goal: |
+      You are a skilled debater arguing FOR the proposition.
+      Be logical, cite evidence, and directly address your opponent's points.
+      Keep each argument concise (under 200 words).
+    capabilities:
+      - argumentation
+      - critical-thinking
+    procedure: |
+      1. Read the opposing side's latest argument carefully.
+      2. Counter their points with evidence and logic.
+      3. If you find yourself genuinely convinced by the other side, you may concede.
+    output: |
+      Provide your argument in the frontmatter.
+      Set conceded to true ONLY if you are genuinely convinced and wish to stop debating.
+    frontmatter:
+      type: object
+      properties:
+        argument:
+          type: string
+        conceded:
+          type: boolean
+      required: [argument, conceded]
+conditions:
+  againstConceded:
+    description: "The against side conceded"
+    expression: "$last('against').conceded = true"
+  forConceded:
+    description: "The for side conceded"
+    expression: "$last('for').conceded = true"
+graph:
+  $START:
+    - role: "against"
+      condition: null
+      prompt: "Present your opening argument against the proposition."
+  against:
+    - role: "$END"
+      condition: "againstConceded"
+      prompt: "The against side conceded. Debate over."
+    - role: "for"
+      condition: null
+      prompt: "Counter the opposing argument. Address their points directly."
+  for:
+    - role: "$END"
+      condition: "forConceded"
+      prompt: "The for side conceded. Debate over."
+    - role: "against"
+      condition: null
+      prompt: "Counter the opposing argument. Address their points directly."
@@ -3,22 +3,35 @@ description: "End-to-end issue resolution"
 roles:
  planner:
    description: "Creates implementation plan"
-    goal: "You are a planning agent. You analyze issues and create step-by-step plans."
+    goal: "You are a planning agent. You analyze issues and create implementation plans grounded in the actual codebase."
    capabilities:
      - issue-analysis
      - planning
-    procedure: "Analyze the issue and create a detailed, actionable implementation plan."
-    output: "Output the plan summary and list of concrete steps."
+      - file-read
+      - shell
+    procedure: |
+      1. Locate the code repository:
+         - Check if the current working directory is the repo (look for package.json, .git, etc.)
+         - If the task mentions a repo URL, clone it first.
+         - If this is a new project, create the repo and note the path.
+      2. Explore the codebase — read the relevant source files mentioned in the issue. Understand the current architecture, types, and conventions (check CLAUDE.md, CONTRIBUTING.md, .cursor/rules/).
+      3. Identify which files need changes and what the changes should be, with specific code references.
+      4. Output the plan with:
+         - `repoPath`: absolute path to the repository root
+         - `plan`: detailed implementation plan with file paths and code references
+         - `steps`: concrete action items for the developer
+    output: |
+      Provide repoPath, plan summary, and steps in the frontmatter.
+      The plan MUST reference actual file paths and code structures you found by reading the source.
+      Do NOT guess — if you haven't read a file, read it before referencing it.
    frontmatter:
      type: object
      properties:
+        repoPath:
+          type: string
        plan:
          type: string
-        steps:
-          type: array
-          items:
-            type: string
-      required: [plan, steps]
+      required: [repoPath, plan]
  developer:
    description: "Implements code changes"
    goal: "You are a developer agent. You implement code changes according to plans."
@@ -26,7 +39,12 @@ roles:
      - file-edit
      - shell
      - testing
-    procedure: "Implement the plan. Write code, tests, and ensure existing tests pass."
+    procedure: |
+      1. Read the planner's output to get the repoPath and implementation plan.
+      2. cd to the repoPath before making any changes.
+      3. Create a feature branch from the default branch.
+      4. Implement the plan — write code, tests, and ensure existing tests pass.
+      5. Commit your changes with a descriptive message referencing the issue.
    output: "List all files changed and provide a summary of the implementation."
    frontmatter:
      type: object
@@ -9,7 +9,7 @@
    "check": "bunx tsc --build && biome check . && bash scripts/lint-log-tags.sh",
    "typecheck": "bunx tsc --build",
    "format": "biome format --write .",
-    "test": "bun run --filter '*' test",
+    "test": "bun run --filter './packages/*' test",
    "changeset": "bunx changeset",
    "version": "bunx changeset version",
    "release": "bun run build && bun test && node scripts/publish-all.mjs"
@@ -0,0 +1,204 @@
+# @uncaged/cli-workflow
+
+`uwf` CLI — thread lifecycle, workflow registry, CAS inspection, and setup.
+
+## Overview
+
+Layer 4 entry point for the workflow engine. The `uwf` binary orchestrates one step per invocation: load thread head from `threads.yaml`, run the moderator, spawn the configured agent CLI, run extract, append a CAS step node, and update the head pointer (or archive when `$END`).
+
+### Four-Layer Architecture
+
+```
+workflow → thread → step → turn
+模板定义   执行实例   单步结果   agent内部交互
+```
+
+- **Workflow** (layer 1): YAML template with roles and routing graph
+- **Thread** (layer 2): Single workflow execution instance
+- **Step** (layer 3): One moderator→agent→extract cycle
+- **Turn** (layer 4): Agent-internal interactions (use `step show` or CAS to inspect)
+
+This package has no library `src/index.ts` — it is consumed as a CLI binary only.
+
+**Dependencies:** `@uncaged/json-cas`, `@uncaged/json-cas-fs`, `@uncaged/workflow-agent-kit`, `@uncaged/workflow-moderator`, `@uncaged/workflow-protocol`, `@uncaged/workflow-util`, `commander`, `dotenv`, `yaml`
+
+## Installation
+
+Included as the `uwf` binary when you install `@uncaged/cli-workflow`:
+
+```bash
+bun add -g @uncaged/cli-workflow
+# or from the monorepo:
+bun link packages/cli-workflow
+```
+
+## CLI Usage
+
+### Global options
+
+```
+-V, --version          Show version
+--format <json|yaml>   Output format (default: json)
+-h, --help             Show help
+```
+
+### Thread (Layer 2: Execution Instances)
+
+| Command | Description |
+|---------|-------------|
+| `uwf thread start <workflow> -p <prompt>` | Create a thread without executing |
+| `uwf thread exec <thread-id> [--agent <cmd>] [-c <count>] [--background]` | Execute one or more moderator→agent→extract cycles |
+| `uwf thread show <thread-id>` | Show thread head pointer |
+| `uwf thread list [--status <idle\|running\|completed>]` | List threads, optionally filtered by status |
+| `uwf thread read <thread-id> [--quota N] [--before <hash>] [--start]` | Render thread as readable markdown |
+| `uwf thread stop <thread-id>` | Stop background execution (keep thread active) |
+| `uwf thread cancel <thread-id>` | Cancel thread (stop + archive to history) |
+
+Examples:
+
+```bash
+uwf thread start solve-issue -p "Fix the login redirect bug"
+uwf thread exec 01ARZ3NDEKTSV4RRFFQ69G5FAV
+uwf thread exec 01ARZ3NDEKTSV4RRFFQ69G5FAV -c 3 --agent uwf-builtin
+uwf thread exec 01ARZ3NDEKTSV4RRFFQ69G5FAV --background
+uwf thread list --status running
+uwf thread read 01ARZ3NDEKTSV4RRFFQ69G5FAV --quota 8000
+uwf thread stop 01ARZ3NDEKTSV4RRFFQ69G5FAV
+```
+
+### Step (Layer 3: Single Cycle Results)
+
+| Command | Description |
+|---------|-------------|
+| `uwf step list <thread-id>` | List all steps in a thread chronologically |
+| `uwf step show <step-hash>` | Show step metadata and frontmatter |
+| `uwf step fork <step-hash>` | Fork a thread from a specific step |
+
+Examples:
+
+```bash
+uwf step list 01ARZ3NDEKTSV4RRFFQ69G5FAV
+uwf step show 32GCDE899RRQ3
+uwf step fork 32GCDE899RRQ3
+```
+
+### Workflow (Layer 1: Templates)
+
+| Command | Description |
+|---------|-------------|
+| `uwf workflow add <file.yaml>` | Register a workflow from YAML |
+| `uwf workflow show <name-or-hash>` | Show workflow definition |
+| `uwf workflow list` | List registered workflows |
+
+### CAS
+
+| Command | Description |
+|---------|-------------|
+| `uwf cas get <hash> [--timestamp]` | Read a CAS node |
+| `uwf cas put <type-hash> <data>` | Store a node, print hash |
+| `uwf cas put-text <text>` | Store plain text, print hash |
+| `uwf cas has <hash>` | Check existence |
+| `uwf cas refs <hash>` | List direct references |
+| `uwf cas walk <hash>` | Recursive traversal |
+| `uwf cas reindex` | Rebuild type index |
+| `uwf cas schema list` | List registered schemas |
+| `uwf cas schema get <hash>` | Show a schema |
+
+### Setup
+
+```bash
+uwf setup
+uwf setup --provider openai --base-url https://api.openai.com/v1 \
+  --api-key sk-... --model gpt-4o --agent hermes
+```
+
+Config: `~/.uncaged/workflow/config.yaml`. API keys: `~/.uncaged/workflow/.env`.
+
+### Skill
+
+| Command | Description |
+|---------|-------------|
+| `uwf skill cli` | Print markdown reference of all uwf commands (for agent skills) |
+
+### Log
+
+| Command | Description |
+|---------|-------------|
+| `uwf log list` | List log files with sizes |
+| `uwf log show [--thread <id>] [--process <pid>] [--date YYYY-MM-DD]` | Show filtered log entries |
+| `uwf log clean [--before YYYY-MM-DD]` | Delete old log files |
+
+## Migration Guide
+
+### Breaking Changes (v0.x → v1.x)
+
+The CLI was reorganized to clarify the four-layer architecture. **No backward compatibility** — old commands have been removed.
+
+#### Renamed Commands
+
+| Old Command | New Command | Notes |
+|------------|-------------|-------|
+| `workflow put` | `workflow add` | More intuitive verb |
+| `thread step` | `thread exec` | Eliminates ambiguity with "step" noun |
+| `thread list --all` | `thread list --status completed` | Unified status filtering |
+
+#### Removed Commands (Merged)
+
+| Old Command | New Command | Notes |
+|------------|-------------|-------|
+| `thread running` | `thread list --status running` | Merged into unified list |
+
+#### Removed Commands (Split)
+
+| Old Command | New Commands | Notes |
+|------------|-------------|-------|
+| `thread kill` | `thread stop` or `thread cancel` | `stop` keeps thread active, `cancel` archives it |
+
+#### Moved Commands
+
+| Old Command | New Command | Notes |
+|------------|-------------|-------|
+| `thread steps` | `step list` | Moved to step layer |
+| `thread step-details` | `step show` | Moved to step layer |
+| `thread fork` | `step fork` | Moved to step layer (forks are step-based) |
+
+#### Deprecation Errors
+
+Old commands now show helpful error messages:
+
+```bash
+$ uwf thread step 01ARZ3NDEKTSV4RRFFQ69G5FAV
+Error: Command 'thread step' has been removed.
+Use 'thread exec' instead.
+
+For more information, see: uwf help thread exec
+```
+
+## Internal Structure
+
+```
+src/
+├── cli.ts              Commander entrypoint, command registration
+├── format.ts           JSON/YAML output formatting
+├── store.ts            CAS store + registry initialization
+├── validate.ts         Workflow YAML validation
+├── schemas.ts          CLI-local schema registration
+└── commands/
+    ├── thread.ts       Thread lifecycle and exec
+    ├── step.ts         Step operations (list/show/read/fork)
+    ├── workflow.ts     Workflow registry (add/show/list)
+    ├── cas.ts          CAS inspection and schema ops
+    ├── setup.ts        Interactive/non-interactive setup
+    ├── skill.ts        Built-in skill references
+    └── log.ts          Process debug log management
+```
+
+## Configuration
+
+| File | Purpose |
+|------|---------|
+| `~/.uncaged/workflow/config.yaml` | Providers, models, default agent |
+| `~/.uncaged/workflow/.env` | API keys (referenced by `apiKeyEnv` in config) |
+| `~/.uncaged/workflow/registry.yaml` | Workflow name → CAS hash |
+| `~/.uncaged/workflow/threads.yaml` | Active thread head pointers |
+| `~/.uncaged/workflow/cas/` | Content-addressed node storage |
@@ -62,9 +62,9 @@ const olderEntry = JSON.stringify({

 async function writeLogFiles(): Promise<void> {
  const logsDir = join(storageRoot, "logs");
-  await writeFile(join(logsDir, "2026-05-20.jsonl"), [entry1, entry2, entry3].join("\n") + "\n");
-  await writeFile(join(logsDir, "2026-05-19.jsonl"), oldEntry + "\n");
-  await writeFile(join(logsDir, "2026-05-18.jsonl"), olderEntry + "\n");
+  await writeFile(join(logsDir, "2026-05-20.jsonl"), `${[entry1, entry2, entry3].join("\n")}\n`);
+  await writeFile(join(logsDir, "2026-05-19.jsonl"), `${oldEntry}\n`);
+  await writeFile(join(logsDir, "2026-05-18.jsonl"), `${olderEntry}\n`);
 }

 describe("cmdLogList", () => {
@@ -0,0 +1,381 @@
+import { mkdirSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, describe, expect, test, vi } from "vitest";
+import {
+  _discoverAgents,
+  _isBackspace,
+  _isTerminator,
+  _parseWhichOutput,
+  _printModelMenu,
+  _printProviderMenu,
+  _printValidationResult,
+  _resolveModelChoice,
+  _resolveProviderChoice,
+  _searchPathDirs,
+} from "../commands/setup.js";
+
+// ──────────────────────────────────────────────────────────────────────────────
+// 1a. _searchPathDirs
+// ──────────────────────────────────────────────────────────────────────────────
+
+describe("_searchPathDirs", () => {
+  test("returns empty array for empty PATH", async () => {
+    const result = await _searchPathDirs("");
+    expect(result).toEqual([]);
+  });
+
+  test("finds uwf-hermes in a single dir", async () => {
+    const dir = mkdirSync(join(tmpdir(), `uwf-test-${Date.now()}`), { recursive: true }) as
+      | string
+      | undefined;
+    const actualDir = dir ?? join(tmpdir(), `uwf-test-${Date.now()}`);
+    mkdirSync(actualDir, { recursive: true });
+    const filePath = join(actualDir, "uwf-hermes");
+    writeFileSync(filePath, "#!/bin/sh\n", { mode: 0o755 });
+    const result = await _searchPathDirs(actualDir);
+    expect(result).toContain("uwf-hermes");
+  });
+
+  test("skips non-uwf- prefixed binaries", async () => {
+    const dir = join(tmpdir(), `uwf-test-${Date.now()}-2`);
+    mkdirSync(dir, { recursive: true });
+    writeFileSync(join(dir, "hermes"), "#!/bin/sh\n", { mode: 0o755 });
+    writeFileSync(join(dir, "uwf-hermes"), "#!/bin/sh\n", { mode: 0o755 });
+    const result = await _searchPathDirs(dir);
+    expect(result).toEqual(["uwf-hermes"]);
+  });
+
+  test("skips entry named exactly 'uwf'", async () => {
+    const dir = join(tmpdir(), `uwf-test-${Date.now()}-3`);
+    mkdirSync(dir, { recursive: true });
+    writeFileSync(join(dir, "uwf"), "#!/bin/sh\n", { mode: 0o755 });
+    writeFileSync(join(dir, "uwf-hermes"), "#!/bin/sh\n", { mode: 0o755 });
+    const result = await _searchPathDirs(dir);
+    expect(result).toEqual(["uwf-hermes"]);
+  });
+
+  test("skips non-executable files", async () => {
+    const dir = join(tmpdir(), `uwf-test-${Date.now()}-4`);
+    mkdirSync(dir, { recursive: true });
+    writeFileSync(join(dir, "uwf-foo"), "#!/bin/sh\n", { mode: 0o644 });
+    const result = await _searchPathDirs(dir);
+    expect(result).toEqual([]);
+  });
+
+  test("deduplicates across PATH dirs", async () => {
+    const dir1 = join(tmpdir(), `uwf-test-${Date.now()}-5a`);
+    const dir2 = join(tmpdir(), `uwf-test-${Date.now()}-5b`);
+    mkdirSync(dir1, { recursive: true });
+    mkdirSync(dir2, { recursive: true });
+    writeFileSync(join(dir1, "uwf-hermes"), "#!/bin/sh\n", { mode: 0o755 });
+    writeFileSync(join(dir2, "uwf-hermes"), "#!/bin/sh\n", { mode: 0o755 });
+    const result = await _searchPathDirs(`${dir1}:${dir2}`);
+    expect(result).toEqual(["uwf-hermes"]);
+  });
+
+  test("returns sorted array", async () => {
+    const dir = join(tmpdir(), `uwf-test-${Date.now()}-6`);
+    mkdirSync(dir, { recursive: true });
+    writeFileSync(join(dir, "uwf-zoo"), "#!/bin/sh\n", { mode: 0o755 });
+    writeFileSync(join(dir, "uwf-alpha"), "#!/bin/sh\n", { mode: 0o755 });
+    writeFileSync(join(dir, "uwf-mid"), "#!/bin/sh\n", { mode: 0o755 });
+    const result = await _searchPathDirs(dir);
+    expect(result).toEqual(["uwf-alpha", "uwf-mid", "uwf-zoo"]);
+  });
+
+  test("skips inaccessible/nonexistent directories silently", async () => {
+    const result = await _searchPathDirs("/nonexistent-dir-xyz-abc-12345");
+    expect(result).toEqual([]);
+  });
+});
+
+// ──────────────────────────────────────────────────────────────────────────────
+// 1b. _parseWhichOutput
+// ──────────────────────────────────────────────────────────────────────────────
+
+describe("_parseWhichOutput", () => {
+  test("returns empty array for empty string", () => {
+    expect(_parseWhichOutput("")).toEqual([]);
+  });
+
+  test("parses single path", () => {
+    expect(_parseWhichOutput("/usr/local/bin/uwf-hermes")).toEqual(["uwf-hermes"]);
+  });
+
+  test("parses multiple paths", () => {
+    expect(_parseWhichOutput("/usr/local/bin/uwf-hermes\n/usr/bin/uwf-claude-code")).toEqual([
+      "uwf-claude-code",
+      "uwf-hermes",
+    ]);
+  });
+
+  test("deduplicates identical basenames from different dirs", () => {
+    expect(_parseWhichOutput("/a/uwf-hermes\n/b/uwf-hermes")).toEqual(["uwf-hermes"]);
+  });
+
+  test("skips blank lines", () => {
+    expect(_parseWhichOutput("/a/uwf-hermes\n\n/b/uwf-cursor")).toEqual([
+      "uwf-cursor",
+      "uwf-hermes",
+    ]);
+  });
+
+  test("skips entry named exactly 'uwf'", () => {
+    expect(_parseWhichOutput("/usr/bin/uwf")).toEqual([]);
+  });
+
+  test("skips basenames not starting with uwf-", () => {
+    expect(_parseWhichOutput("/usr/bin/node")).toEqual([]);
+  });
+
+  test("returns sorted array", () => {
+    expect(_parseWhichOutput("/a/uwf-zoo\n/a/uwf-alpha")).toEqual(["uwf-alpha", "uwf-zoo"]);
+  });
+});
+
+// ──────────────────────────────────────────────────────────────────────────────
+// 2a. _isTerminator
+// ──────────────────────────────────────────────────────────────────────────────
+
+describe("_isTerminator", () => {
+  test("\\n is a terminator", () => {
+    expect(_isTerminator("\n")).toBe(true);
+  });
+  test("\\r is a terminator", () => {
+    expect(_isTerminator("\r")).toBe(true);
+  });
+  test("\\u0004 (EOT) is a terminator", () => {
+    expect(_isTerminator("")).toBe(true);
+  });
+  test("regular char is not a terminator", () => {
+    expect(_isTerminator("a")).toBe(false);
+  });
+  test("empty string is not a terminator", () => {
+    expect(_isTerminator("")).toBe(false);
+  });
+});
+
+// ──────────────────────────────────────────────────────────────────────────────
+// 2b. _isBackspace
+// ──────────────────────────────────────────────────────────────────────────────
+
+describe("_isBackspace", () => {
+  test("\\u007F is a backspace", () => {
+    expect(_isBackspace("")).toBe(true);
+  });
+  test("\\b is a backspace", () => {
+    expect(_isBackspace("\b")).toBe(true);
+  });
+  test("regular char is not a backspace", () => {
+    expect(_isBackspace("x")).toBe(false);
+  });
+});
+
+// ──────────────────────────────────────────────────────────────────────────────
+// 3a. _printProviderMenu
+// ──────────────────────────────────────────────────────────────────────────────
+
+describe("_printProviderMenu", () => {
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  const providers = [
+    { name: "openai", label: "OpenAI", baseUrl: "https://api.openai.com/v1" },
+    { name: "xai", label: "xAI", baseUrl: "https://api.x.ai/v1" },
+  ] as const;
+
+  test("prints correct number of lines (one per provider + custom)", () => {
+    const lines: string[] = [];
+    vi.spyOn(console, "log").mockImplementation((msg: string) => {
+      lines.push(msg);
+    });
+    _printProviderMenu(providers);
+    // 2 providers + 1 custom = 3 lines
+    expect(lines.length).toBe(3);
+  });
+
+  test("custom option number = providers.length + 1", () => {
+    const lines: string[] = [];
+    vi.spyOn(console, "log").mockImplementation((msg: string) => {
+      lines.push(msg);
+    });
+    _printProviderMenu(providers);
+    const lastLine = lines[lines.length - 1] ?? "";
+    expect(lastLine).toMatch(/3\)/);
+  });
+
+  test("each provider line contains its label and baseUrl", () => {
+    const lines: string[] = [];
+    vi.spyOn(console, "log").mockImplementation((msg: string) => {
+      lines.push(msg);
+    });
+    _printProviderMenu(providers);
+    expect(lines[0]).toContain("OpenAI");
+    expect(lines[0]).toContain("https://api.openai.com/v1");
+    expect(lines[1]).toContain("xAI");
+    expect(lines[1]).toContain("https://api.x.ai/v1");
+  });
+});
+
+// ──────────────────────────────────────────────────────────────────────────────
+// 3b. _resolveProviderChoice
+// ──────────────────────────────────────────────────────────────────────────────
+
+describe("_resolveProviderChoice", () => {
+  const providers = [
+    { name: "openai", label: "OpenAI", baseUrl: "https://api.openai.com/v1" },
+    { name: "xai", label: "xAI", baseUrl: "https://api.x.ai/v1" },
+    { name: "deepseek", label: "DeepSeek", baseUrl: "https://api.deepseek.com/v1" },
+  ] as const;
+
+  test("valid index 1 returns first provider", () => {
+    const result = _resolveProviderChoice("1", providers);
+    expect(result).toEqual({ providerName: "openai", baseUrl: "https://api.openai.com/v1" });
+  });
+
+  test("valid index N (last preset) returns last provider", () => {
+    const result = _resolveProviderChoice("3", providers);
+    expect(result).toEqual({ providerName: "deepseek", baseUrl: "https://api.deepseek.com/v1" });
+  });
+
+  test("index providers.length+1 (custom) returns null", () => {
+    const result = _resolveProviderChoice("4", providers);
+    expect(result).toBeNull();
+  });
+
+  test("non-numeric string returns null", () => {
+    expect(_resolveProviderChoice("abc", providers)).toBeNull();
+  });
+
+  test("0 returns null (out of range)", () => {
+    expect(_resolveProviderChoice("0", providers)).toBeNull();
+  });
+
+  test("N+2 returns null (out of range)", () => {
+    expect(_resolveProviderChoice("5", providers)).toBeNull();
+  });
+
+  test("negative number returns null", () => {
+    expect(_resolveProviderChoice("-1", providers)).toBeNull();
+  });
+});
+
+// ──────────────────────────────────────────────────────────────────────────────
+// 3c. _resolveModelChoice
+// ──────────────────────────────────────────────────────────────────────────────
+
+describe("_resolveModelChoice", () => {
+  test("numeric input within range returns model at that index", () => {
+    expect(_resolveModelChoice("2", ["a", "b", "c"])).toBe("b");
+  });
+
+  test("numeric input out of range returns input as-is", () => {
+    expect(_resolveModelChoice("5", ["a"])).toBe("5");
+  });
+
+  test("non-numeric input returns input as-is", () => {
+    expect(_resolveModelChoice("gpt-4o", ["a", "b"])).toBe("gpt-4o");
+  });
+
+  test("numeric input 1 returns first model", () => {
+    expect(_resolveModelChoice("1", ["alpha", "beta"])).toBe("alpha");
+  });
+
+  test("empty models list with numeric input returns input as-is", () => {
+    expect(_resolveModelChoice("1", [])).toBe("1");
+  });
+});
+
+// ──────────────────────────────────────────────────────────────────────────────
+// 3d. _printModelMenu
+// ──────────────────────────────────────────────────────────────────────────────
+
+describe("_printModelMenu", () => {
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  test("prints all models — each model name appears in output", () => {
+    const output: string[] = [];
+    vi.spyOn(console, "log").mockImplementation((msg: string) => {
+      output.push(msg);
+    });
+    const models = ["model-a", "model-b", "model-c"];
+    _printModelMenu(models, 100);
+    const combined = output.join("\n");
+    for (const m of models) {
+      expect(combined).toContain(m);
+    }
+  });
+
+  test("single column when termCols is very small", () => {
+    const output: string[] = [];
+    vi.spyOn(console, "log").mockImplementation((msg: string) => {
+      output.push(msg);
+    });
+    _printModelMenu(["a", "b", "c"], 1);
+    // Each model on its own row → 3 lines
+    expect(output.length).toBe(3);
+  });
+
+  test("wide terminal fits multiple columns", () => {
+    const output: string[] = [];
+    vi.spyOn(console, "log").mockImplementation((msg: string) => {
+      output.push(msg);
+    });
+    const models = Array.from({ length: 6 }, (_, i) => `m${i}`);
+    _printModelMenu(models, 200);
+    // With wide terminal and short names, should fit in fewer than 6 rows
+    expect(output.length).toBeLessThan(6);
+  });
+});
+
+// ──────────────────────────────────────────────────────────────────────────────
+// 3e. _printValidationResult
+// ──────────────────────────────────────────────────────────────────────────────
+
+describe("_printValidationResult", () => {
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  test("ok=true prints success message containing '✓'", () => {
+    const lines: string[] = [];
+    vi.spyOn(console, "log").mockImplementation((msg: string) => {
+      lines.push(msg);
+    });
+    _printValidationResult({ ok: true, error: null });
+    expect(lines.join("\n")).toContain("✓");
+  });
+
+  test("ok=false prints warning message containing '⚠'", () => {
+    const lines: string[] = [];
+    vi.spyOn(console, "log").mockImplementation((msg: string) => {
+      lines.push(msg);
+    });
+    _printValidationResult({ ok: false, error: "HTTP 401" });
+    expect(lines.join("\n")).toContain("⚠");
+  });
+
+  test("ok=false includes the error string in output", () => {
+    const lines: string[] = [];
+    vi.spyOn(console, "log").mockImplementation((msg: string) => {
+      lines.push(msg);
+    });
+    _printValidationResult({ ok: false, error: "HTTP 401" });
+    expect(lines.join("\n")).toContain("HTTP 401");
+  });
+});
+
+// ──────────────────────────────────────────────────────────────────────────────
+// 4. Regression
+// ──────────────────────────────────────────────────────────────────────────────
+
+describe("_discoverAgents regression", () => {
+  test("returns an array (may be empty) — never throws", async () => {
+    const result = await _discoverAgents();
+    expect(Array.isArray(result)).toBe(true);
+  });
+});
@@ -0,0 +1,683 @@
+import { mkdir, mkdtemp, rm } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { bootstrap, putSchema } from "@uncaged/json-cas";
+import { createFsStore } from "@uncaged/json-cas-fs";
+import type { CasRef, ThreadId } from "@uncaged/workflow-protocol";
+import { afterEach, beforeEach, describe, expect, test } from "vitest";
+import { cmdThreadRead, THREAD_READ_DEFAULT_QUOTA } from "../commands/thread.js";
+import { registerUwfSchemas } from "../schemas.js";
+import type { UwfStore } from "../store.js";
+import { saveThreadsIndex } from "../store.js";
+
+// ── schemas used in tests ────────────────────────────────────────────────────
+
+const TURN_SCHEMA = {
+  title: "hermes-turn",
+  type: "object" as const,
+  required: ["index", "role", "content"],
+  properties: {
+    index: { type: "integer" as const },
+    role: { type: "string" as const },
+    content: { type: "string" as const },
+    toolCalls: {
+      anyOf: [
+        { type: "array" as const, items: { type: "object" as const } },
+        { type: "null" as const },
+      ],
+    },
+    reasoning: { anyOf: [{ type: "string" as const }, { type: "null" as const }] },
+  },
+  additionalProperties: false,
+};
+
+const DETAIL_SCHEMA = {
+  title: "hermes-detail",
+  type: "object" as const,
+  required: ["sessionId", "model", "duration", "turnCount", "turns"],
+  properties: {
+    sessionId: { type: "string" as const },
+    model: { type: "string" as const },
+    duration: { type: "integer" as const },
+    turnCount: { type: "integer" as const },
+    turns: {
+      type: "array" as const,
+      items: { type: "string" as const, format: "cas_ref" },
+    },
+  },
+  additionalProperties: false,
+};
+
+// ── helpers ───────────────────────────────────────────────────────────────────
+
+async function makeUwfStore(storageRoot: string): Promise<UwfStore> {
+  const casDir = join(storageRoot, "cas");
+  await mkdir(casDir, { recursive: true });
+  const store = createFsStore(casDir);
+  const schemas = await registerUwfSchemas(store);
+  return { storageRoot, store, schemas };
+}
+
+async function registerDetailSchemas(store: ReturnType<typeof createFsStore>) {
+  await bootstrap(store);
+  const [turn, detail] = await Promise.all([
+    putSchema(store, TURN_SCHEMA),
+    putSchema(store, DETAIL_SCHEMA),
+  ]);
+  return { turn, detail };
+}
+
+// ── fixture ───────────────────────────────────────────────────────────────────
+
+let tmpDir: string;
+
+beforeEach(async () => {
+  tmpDir = await mkdtemp(join(tmpdir(), "cli-uwf-test-"));
+});
+
+afterEach(async () => {
+  await rm(tmpDir, { recursive: true, force: true });
+});
+
+// ── thread read XML tag isolation ─────────────────────────────────────────────
+
+describe("thread read XML tag isolation", () => {
+  test("scenario 1: wraps output in XML tags instead of heading", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+    const detailSchemas = await registerDetailSchemas(uwf.store);
+
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "test-wf",
+      description: "desc",
+      roles: {
+        planner: {
+          description: "Planner",
+          goal: "You are a planning agent. Your task is to...",
+          capabilities: [],
+          procedure: "Plan the work.",
+          output: "Summarize the plan.",
+          meta: "placeholder00" as CasRef,
+        },
+      },
+      conditions: {},
+      graph: {},
+    });
+
+    const startHash = await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Fix issue #459",
+    });
+
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const turnHash = await uwf.store.put(detailSchemas.turn, {
+      index: 0,
+      role: "assistant",
+      content:
+        "---\nstatus: ready\nplan: CMWGHQKT58RY4\n---\n\n# Analysis Complete\n## Issue Summary\nThe issue requires XML tag isolation.",
+      toolCalls: null,
+      reasoning: null,
+    });
+    const detailHash = await uwf.store.put(detailSchemas.detail, {
+      sessionId: "sx",
+      model: "mx",
+      duration: 500,
+      turnCount: 1,
+      turns: [turnHash],
+    });
+
+    const stepHash = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: null,
+      role: "planner",
+      output: outputHash,
+      detail: detailHash,
+      agent: "uwf-claude-code",
+    });
+
+    const threadId = "01JTEST0000000000000001" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: stepHash });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
+
+    // Should wrap output in XML tags
+    expect(markdown).toContain("<output>");
+    expect(markdown).toContain("</output>");
+
+    // Should not have ### Content heading
+    expect(markdown).not.toContain("### Content");
+
+    // Should preserve markdown headings inside output tags
+    expect(markdown).toContain("# Analysis Complete");
+    expect(markdown).toContain("## Issue Summary");
+  });
+
+  test("scenario 2: wraps prompt in XML tags", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+    const detailSchemas = await registerDetailSchemas(uwf.store);
+
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "test-wf",
+      description: "desc",
+      roles: {
+        planner: {
+          description: "Planner",
+          goal: "You are a planning agent. Your task is to analyze and plan.",
+          capabilities: [],
+          procedure: "Plan the work.",
+          output: "Summarize the plan.",
+          meta: "placeholder00" as CasRef,
+        },
+      },
+      conditions: {},
+      graph: {},
+    });
+
+    const startHash = await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Fix issue",
+    });
+
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const turnHash = await uwf.store.put(detailSchemas.turn, {
+      index: 0,
+      role: "assistant",
+      content: "---\nstatus: ready\n---\n\nContent here...",
+      toolCalls: null,
+      reasoning: null,
+    });
+    const detailHash = await uwf.store.put(detailSchemas.detail, {
+      sessionId: "sx",
+      model: "mx",
+      duration: 500,
+      turnCount: 1,
+      turns: [turnHash],
+    });
+
+    const stepHash = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: null,
+      role: "planner",
+      output: outputHash,
+      detail: detailHash,
+      agent: "uwf-claude-code",
+    });
+
+    const threadId = "01JTEST0000000000000002" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: stepHash });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
+
+    // Should wrap prompt in XML tags
+    expect(markdown).toContain("<prompt>");
+    expect(markdown).toContain("</prompt>");
+    expect(markdown).toContain("You are a planning agent. Your task is to analyze and plan.");
+
+    // Should not have ### Prompt heading
+    expect(markdown).not.toContain("### Prompt");
+
+    // Should wrap output in XML tags
+    expect(markdown).toContain("<output>");
+    expect(markdown).toContain("</output>");
+  });
+
+  test("scenario 3: same role repeated does not show prompt twice", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "test-wf",
+      description: "desc",
+      roles: {
+        writer: {
+          description: "Writer",
+          goal: "You are a writer agent.",
+          capabilities: [],
+          procedure: "Write content.",
+          output: "Summarize writing.",
+          meta: "placeholder00" as CasRef,
+        },
+      },
+      conditions: {},
+      graph: {},
+    });
+
+    const startHash = await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Write something",
+    });
+
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const step1 = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: null,
+      role: "writer",
+      output: outputHash,
+      detail: null,
+      agent: "uwf-test",
+    });
+
+    const step2 = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: step1 as CasRef,
+      role: "writer",
+      output: outputHash,
+      detail: null,
+      agent: "uwf-test",
+    });
+
+    const threadId = "01JTEST0000000000000003" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: step2 });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
+
+    // Should only show prompt tags once
+    const promptCount = (markdown.match(/<prompt>/g) ?? []).length;
+    expect(promptCount).toBe(1);
+  });
+
+  test("scenario 4: step with no detail shows no output tags", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "test-wf",
+      description: "desc",
+      roles: {
+        worker: {
+          description: "Worker",
+          goal: "You are a worker agent.",
+          capabilities: [],
+          procedure: "Do work.",
+          output: "Summarize work.",
+          meta: "placeholder00" as CasRef,
+        },
+      },
+      conditions: {},
+      graph: {},
+    });
+
+    const startHash = await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Do stuff",
+    });
+
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const stepHash = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: null,
+      role: "worker",
+      output: outputHash,
+      detail: null,
+      agent: "uwf-test",
+    });
+
+    const threadId = "01JTEST0000000000000004" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: stepHash });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
+
+    // Should not have output tags
+    expect(markdown).not.toContain("<output>");
+    expect(markdown).not.toContain("</output>");
+
+    // Step header should still be displayed
+    expect(markdown).toContain("## Step 1: worker");
+
+    // Prompt should still be shown
+    expect(markdown).toContain("<prompt>");
+  });
+
+  test("scenario 5: empty content shows no output tags", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "test-wf",
+      description: "desc",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const startHash = await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Do stuff",
+    });
+
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    // A detail ref that doesn't exist → extractLastAssistantContent returns null
+    const missingDetailRef = "missingdetail0" as CasRef;
+
+    const stepHash = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: null,
+      role: "worker",
+      output: outputHash,
+      detail: missingDetailRef,
+      agent: "uwf-test",
+    });
+
+    const threadId = "01JTEST0000000000000005" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: stepHash });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
+
+    // Should not have output tags
+    expect(markdown).not.toContain("<output>");
+    expect(markdown).not.toContain("</output>");
+  });
+
+  test("scenario 6: thread read with --start flag shows task section", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "test-wf",
+      description: "desc",
+      roles: {
+        roleA: {
+          description: "Role A",
+          goal: "Goal for roleA",
+          capabilities: [],
+          procedure: "Do stuff.",
+          output: "Output.",
+          meta: "placeholder00" as CasRef,
+        },
+      },
+      conditions: {},
+      graph: {},
+    });
+
+    const startHash = await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Initial prompt",
+    });
+
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const stepHash = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: null,
+      role: "roleA",
+      output: outputHash,
+      detail: null,
+      agent: "uwf-test",
+    });
+
+    const threadId = "01JTEST0000000000000006" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: stepHash });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, true);
+
+    // Should include task section
+    expect(markdown).toContain("# Thread");
+    expect(markdown).toContain("## Task");
+    expect(markdown).toContain("Initial prompt");
+
+    // Prompts should use XML tags
+    expect(markdown).toContain("<prompt>");
+  });
+
+  test("scenario 7: thread read with --before parameter", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "test-wf",
+      description: "desc",
+      roles: {
+        roleA: {
+          description: "Role A",
+          goal: "Goal for roleA",
+          capabilities: [],
+          procedure: "Do stuff.",
+          output: "Output.",
+          meta: "placeholder00" as CasRef,
+        },
+        roleB: {
+          description: "Role B",
+          goal: "Goal for roleB",
+          capabilities: [],
+          procedure: "Do stuff.",
+          output: "Output.",
+          meta: "placeholder00" as CasRef,
+        },
+        roleC: {
+          description: "Role C",
+          goal: "Goal for roleC",
+          capabilities: [],
+          procedure: "Do stuff.",
+          output: "Output.",
+          meta: "placeholder00" as CasRef,
+        },
+      },
+      conditions: {},
+      graph: {},
+    });
+
+    const startHash = await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Initial prompt",
+    });
+
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const step1 = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: null,
+      role: "roleA",
+      output: outputHash,
+      detail: null,
+      agent: "uwf-test",
+    });
+
+    const step2 = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: step1 as CasRef,
+      role: "roleB",
+      output: outputHash,
+      detail: null,
+      agent: "uwf-test",
+    });
+
+    const step3 = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: step2 as CasRef,
+      role: "roleC",
+      output: outputHash,
+      detail: null,
+      agent: "uwf-test",
+    });
+
+    const threadId = "01JTEST0000000000000007" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: step3 });
+
+    const markdown = await cmdThreadRead(
+      tmpDir,
+      threadId,
+      THREAD_READ_DEFAULT_QUOTA,
+      step2 as CasRef,
+      false,
+    );
+
+    // Should only show roleA
+    expect(markdown).toContain("roleA");
+    expect(markdown).not.toContain("roleB");
+    expect(markdown).not.toContain("roleC");
+
+    // Should use XML tags
+    expect(markdown).toContain("<prompt>");
+  });
+
+  test("scenario 9: special characters in content are preserved", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+    const detailSchemas = await registerDetailSchemas(uwf.store);
+
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "test-wf",
+      description: "desc",
+      roles: {
+        writer: {
+          description: "Writer",
+          goal: "You are a writer.",
+          capabilities: [],
+          procedure: "Write content.",
+          output: "Summarize.",
+          meta: "placeholder00" as CasRef,
+        },
+      },
+      conditions: {},
+      graph: {},
+    });
+
+    const startHash = await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Write something",
+    });
+
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const turnHash = await uwf.store.put(detailSchemas.turn, {
+      index: 0,
+      role: "assistant",
+      content: "Content with <special> & characters > like <this>",
+      toolCalls: null,
+      reasoning: null,
+    });
+    const detailHash = await uwf.store.put(detailSchemas.detail, {
+      sessionId: "sx",
+      model: "mx",
+      duration: 500,
+      turnCount: 1,
+      turns: [turnHash],
+    });
+
+    const stepHash = await uwf.store.put(uwf.schemas.stepNode, {
+      start: startHash,
+      prev: null,
+      role: "writer",
+      output: outputHash,
+      detail: detailHash,
+      agent: "uwf-test",
+    });
+
+    const threadId = "01JTEST0000000000000008" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: stepHash });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
+
+    // Special characters should be preserved as-is
+    expect(markdown).toContain("Content with <special> & characters > like <this>");
+  });
+
+  test("scenario 10: quota limit with XML tags", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "test-wf",
+      description: "desc",
+      roles: {
+        roleA: {
+          description: "Role A",
+          goal: "Goal for roleA",
+          capabilities: [],
+          procedure: "Do stuff.",
+          output: "Output.",
+          meta: "placeholder00" as CasRef,
+        },
+      },
+      conditions: {},
+      graph: {},
+    });
+
+    const startHash = await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Initial prompt",
+    });
+
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const steps: CasRef[] = [];
+    let prev: CasRef | null = null;
+    for (let i = 0; i < 5; i++) {
+      const step = (await uwf.store.put(uwf.schemas.stepNode, {
+        start: startHash,
+        prev,
+        role: "roleA",
+        output: outputHash,
+        detail: null,
+        agent: "uwf-test",
+      })) as CasRef;
+      steps.push(step);
+      prev = step;
+    }
+
+    const threadId = "01JTEST0000000000000009" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: steps[steps.length - 1]! });
+
+    // Use very small quota
+    const markdown = await cmdThreadRead(tmpDir, threadId, 1, null, false);
+
+    // Should have skip hint
+    expect(markdown).toContain("earlier step");
+
+    // Should have XML tags for displayed steps
+    if (markdown.includes("<prompt>")) {
+      expect(markdown).toContain("</prompt>");
+    }
+  });
+});
@@ -22,48 +22,48 @@ function runCli(args: string[]): { stdout: string; stderr: string; exitCode: num
  }
 }

-describe("thread step --count CLI parsing", () => {
+describe("thread exec --count CLI parsing", () => {
  test("--help shows -c/--count option", () => {
-    const result = runCli(["thread", "step", "--help"]);
+    const result = runCli(["thread", "exec", "--help"]);
    expect(result.stdout).toContain("--count");
    expect(result.stdout).toContain("-c");
  });

  test("description says 'one or more steps'", () => {
-    const result = runCli(["thread", "step", "--help"]);
+    const result = runCli(["thread", "exec", "--help"]);
    expect(result.stdout).toContain("one or more steps");
  });
 });

-describe("cmdThreadStep count logic", () => {
+describe("cmdThreadExec count logic", () => {
  test("count=0 fails with validation error", () => {
-    const result = runCli(["thread", "step", "FAKE_THREAD_ID", "-c", "0"]);
+    const result = runCli(["thread", "exec", "FAKE_THREAD_ID", "-c", "0"]);
    expect(result.exitCode).not.toBe(0);
    expect(result.stderr).toContain("positive integer");
  });

  test("negative count fails with validation error", () => {
-    const result = runCli(["thread", "step", "FAKE_THREAD_ID", "-c", "-1"]);
+    const result = runCli(["thread", "exec", "FAKE_THREAD_ID", "-c", "-1"]);
    expect(result.exitCode).not.toBe(0);
    expect(result.stderr).toContain("positive integer");
  });

  test("non-integer count fails with validation error", () => {
-    const result = runCli(["thread", "step", "FAKE_THREAD_ID", "-c", "1.5"]);
+    const result = runCli(["thread", "exec", "FAKE_THREAD_ID", "-c", "1.5"]);
    expect(result.exitCode).not.toBe(0);
    expect(result.stderr).toContain("positive integer");
  });

  test("count=1 is the default (no -c flag)", () => {
    // Without -c, it should attempt to run 1 step (failing on missing thread, not on count validation)
-    const result = runCli(["thread", "step", "FAKE_THREAD_ID"]);
+    const result = runCli(["thread", "exec", "FAKE_THREAD_ID"]);
    expect(result.exitCode).not.toBe(0);
    // Should NOT contain "positive integer" error — should fail on thread lookup instead
    expect(result.stderr).not.toContain("positive integer");
  });

  test("count=3 passes validation (fails on thread lookup)", () => {
-    const result = runCli(["thread", "step", "FAKE_THREAD_ID", "-c", "3"]);
+    const result = runCli(["thread", "exec", "FAKE_THREAD_ID", "-c", "3"]);
    expect(result.exitCode).not.toBe(0);
    // Should NOT contain "positive integer" error — should fail on thread/storage lookup
    expect(result.stderr).not.toContain("positive integer");
@@ -5,9 +5,9 @@ import { bootstrap, putSchema } from "@uncaged/json-cas";
 import { createFsStore } from "@uncaged/json-cas-fs";
 import type { CasRef, ThreadId } from "@uncaged/workflow-protocol";
 import { afterEach, beforeEach, describe, expect, test } from "vitest";
+import { cmdStepShow } from "../commands/step.js";
 import {
  cmdThreadRead,
-  cmdThreadStepDetails,
  extractLastAssistantContent,
  THREAD_READ_DEFAULT_QUOTA,
 } from "../commands/thread.js";
@@ -198,10 +198,10 @@ describe("extractLastAssistantContent", () => {
  });
 });

-// ── cmdThreadRead: ### Content section ───────────────────────────────────────
+// ── cmdThreadRead: <output> section ──────────────────────────────────────────

-describe("cmdThreadRead ### Content section", () => {
-  test("includes ### Content before ### Output when detail has assistant turns", async () => {
+describe("cmdThreadRead <output> section", () => {
+  test("includes <output> tags when detail has assistant turns", async () => {
    const uwf = await makeUwfStore(tmpDir);
    const detailSchemas = await registerDetailSchemas(uwf.store);

@@ -264,17 +264,13 @@ describe("cmdThreadRead ### Content section", () => {

    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);

-    expect(markdown).toContain("### Content");
+    expect(markdown).toContain("<output>");
+    expect(markdown).toContain("</output>");
    expect(markdown).toContain("The assistant response text");
-
-    const contentIdx = markdown.indexOf("### Content");
-    const outputIdx = markdown.indexOf("### Output");
-    expect(contentIdx).toBeGreaterThanOrEqual(0);
-    expect(outputIdx).toBeGreaterThanOrEqual(0);
-    expect(contentIdx).toBeLessThan(outputIdx);
+    expect(markdown).not.toContain("### Content");
  });

-  test("omits ### Content when detail has no matching assistant turns", async () => {
+  test("omits <output> tags when detail has no matching assistant turns", async () => {
    const uwf = await makeUwfStore(tmpDir);

    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
@@ -313,14 +309,15 @@ describe("cmdThreadRead ### Content section", () => {

    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);

+    expect(markdown).not.toContain("<output>");
+    expect(markdown).not.toContain("</output>");
    expect(markdown).not.toContain("### Content");
-    expect(markdown).toContain("### Output");
  });
 });

-// ── cmdThreadStepDetails ──────────────────────────────────────────────────────
+// ── cmdStepShow ───────────────────────────────────────────────────────────────

-describe("cmdThreadStepDetails", () => {
+describe("cmdStepShow", () => {
  test("returns expanded detail node with turns inlined", async () => {
    const uwf = await makeUwfStore(tmpDir);
    const detailSchemas = await registerDetailSchemas(uwf.store);
@@ -368,7 +365,7 @@ describe("cmdThreadStepDetails", () => {
      agent: "uwf-hermes",
    });

-    const result = await cmdThreadStepDetails(tmpDir, stepHash);
+    const result = await cmdStepShow(tmpDir, stepHash);

    expect(result).toMatchObject({
      sessionId: "sess42",
@@ -387,8 +384,266 @@ describe("cmdThreadStepDetails", () => {
      content: "done",
    });
  });
+});

-  test("throws when step hash does not exist", async () => {
-    await expect(cmdThreadStepDetails(tmpDir, "nonexistenth0" as CasRef)).rejects.toThrow();
+// ── cmdThreadRead: <prompt> deduplication ────────────────────────────────────
+
+describe("cmdThreadRead <prompt> deduplication", () => {
+  async function makeThreadWithRoles(uwf: UwfStore, roles: string[]): Promise<string> {
+    const roleMap: Record<string, unknown> = {};
+    for (const r of [...new Set(roles)]) {
+      roleMap[r] = {
+        description: r,
+        goal: `Goal for ${r}`,
+        capabilities: [],
+        procedure: "Do stuff.",
+        output: "Output.",
+        meta: "placeholder00" as CasRef,
+      };
+    }
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "dedup-wf",
+      description: "desc",
+      roles: roleMap,
+      conditions: {},
+      graph: {},
+    });
+    const startHash = await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Start",
+    });
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    let prev: string | null = null;
+    let stepHash = "";
+    for (const role of roles) {
+      stepHash = await uwf.store.put(uwf.schemas.stepNode, {
+        start: startHash,
+        prev: prev as CasRef | null,
+        role,
+        output: outputHash,
+        detail: null,
+        agent: "uwf-test",
+      });
+      prev = stepHash;
+    }
+    return stepHash;
+  }
+
+  test("same consecutive role shows <prompt> once", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+    const headHash = await makeThreadWithRoles(uwf, ["writer", "writer"]);
+    const threadId = "01JTEST0000000000000003" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: headHash });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
+    const count = (markdown.match(/<prompt>/g) ?? []).length;
+    expect(count).toBe(1);
+  });
+
+  test("different consecutive roles each show <prompt>", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+    const headHash = await makeThreadWithRoles(uwf, ["planner", "coder"]);
+    const threadId = "01JTEST0000000000000004" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: headHash });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
+    const count = (markdown.match(/<prompt>/g) ?? []).length;
+    expect(count).toBe(2);
+  });
+
+  test("non-consecutive same role shows <prompt> twice", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+    const headHash = await makeThreadWithRoles(uwf, ["roleA", "roleB", "roleA"]);
+    const threadId = "01JTEST0000000000000005" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: headHash });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
+    const count = (markdown.match(/<prompt>/g) ?? []).length;
+    expect(count).toBe(2);
+  });
+});
+
+// ── cmdThreadRead: showStart / before / quota ─────────────────────────────────
+
+describe("cmdThreadRead start section / before / quota", () => {
+  async function makeSimpleThread(
+    uwf: UwfStore,
+    roles: string[],
+  ): Promise<{ startHash: CasRef; stepHashes: CasRef[] }> {
+    const uniqueRoles = [...new Set(roles)];
+    const workflowHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "simple-wf",
+      description: "desc",
+      roles: Object.fromEntries(
+        uniqueRoles.map((r) => [
+          r,
+          {
+            description: r,
+            goal: `Goal for ${r}`,
+            capabilities: [],
+            procedure: "Do stuff.",
+            output: "Output.",
+            meta: "placeholder00" as CasRef,
+          },
+        ]),
+      ),
+      conditions: {},
+      graph: {},
+    });
+    const startHash = (await uwf.store.put(uwf.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "Initial prompt",
+    })) as CasRef;
+    const outputHash = await uwf.store.put(uwf.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+
+    const stepHashes: CasRef[] = [];
+    let prev: CasRef | null = null;
+    for (const role of roles) {
+      const stepHash = (await uwf.store.put(uwf.schemas.stepNode, {
+        start: startHash,
+        prev,
+        role,
+        output: outputHash,
+        detail: null,
+        agent: "uwf-test",
+      })) as CasRef;
+      stepHashes.push(stepHash);
+      prev = stepHash;
+    }
+    return { startHash, stepHashes };
+  }
+
+  test("showStart=true includes # Thread header and ## Task section", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+    const { stepHashes } = await makeSimpleThread(uwf, ["roleA"]);
+    const threadId = "01JTEST0000000000000006" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: stepHashes[stepHashes.length - 1]! });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, true);
+    expect(markdown).toContain("# Thread");
+    expect(markdown).toContain("## Task");
+    expect(markdown).toContain("Initial prompt");
+  });
+
+  test("showStart=false with before=null still shows # Thread header (default behavior)", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+    const { stepHashes } = await makeSimpleThread(uwf, ["roleA"]);
+    const threadId = "01JTEST0000000000000007" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: stepHashes[stepHashes.length - 1]! });
+
+    // When before=null, the start section is always shown regardless of showStart
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
+    expect(markdown).toContain("# Thread");
+    expect(markdown).toContain("## Task");
+  });
+
+  test("before filter: only steps before the given hash appear", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+    const { stepHashes } = await makeSimpleThread(uwf, ["roleA", "roleB", "roleC"]);
+    const [_hashA, hashB, hashC] = stepHashes as [CasRef, CasRef, CasRef];
+    const threadId = "01JTEST0000000000000008" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: hashC });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, hashB, false);
+    expect(markdown).toContain("roleA");
+    expect(markdown).not.toContain("roleB");
+    expect(markdown).not.toContain("roleC");
+  });
+
+  test("quota=1 limits output and includes skip hint", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+    const { stepHashes } = await makeSimpleThread(uwf, ["roleA", "roleB", "roleC"]);
+    const threadId = "01JTEST000000000000000A" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: stepHashes[stepHashes.length - 1]! });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, 1, null, false);
+    expect(markdown).toContain("earlier step");
+  });
+
+  test("all steps fit in quota: no skip hint", async () => {
+    const uwf = await makeUwfStore(tmpDir);
+    const { stepHashes } = await makeSimpleThread(uwf, ["roleA"]);
+    const threadId = "01JTEST000000000000000B" as ThreadId;
+    await saveThreadsIndex(tmpDir, { [threadId]: stepHashes[0]! });
+
+    const markdown = await cmdThreadRead(tmpDir, threadId, THREAD_READ_DEFAULT_QUOTA, null, false);
+    expect(markdown).not.toContain("earlier step");
+  });
+});
+
+// ── Tests that call process.exit must be last ─────────────────────────────────
+
+describe("cmdStepShow (process.exit tests - must be last)", () => {
+  test("throws when step hash does not exist", async () => {
+    await expect(cmdStepShow(tmpDir, "nonexistenth0" as CasRef)).rejects.toThrow();
+  });
+
+  test("before with unknown hash rejects", async () => {
+    const _uwf = await makeUwfStore(tmpDir);
+    const casDir = join(tmpDir, "cas");
+    await mkdir(casDir, { recursive: true });
+    const store = createFsStore(casDir);
+    const schemas = await registerUwfSchemas(store);
+    const uwfStore: UwfStore = { storageRoot: tmpDir, store, schemas };
+
+    const workflowHash = await uwfStore.store.put(uwfStore.schemas.workflow, {
+      name: "wf2",
+      description: "",
+      roles: {
+        roleA: {
+          description: "r",
+          goal: "g",
+          capabilities: [],
+          procedure: "p",
+          output: "o",
+          meta: "placeholder00" as CasRef,
+        },
+      },
+      conditions: {},
+      graph: {},
+    });
+    const startHash = await uwfStore.store.put(uwfStore.schemas.startNode, {
+      workflow: workflowHash,
+      prompt: "p",
+    });
+    const outputHash = await uwfStore.store.put(uwfStore.schemas.workflow, {
+      name: "out",
+      description: "",
+      roles: {},
+      conditions: {},
+      graph: {},
+    });
+    const stepHash = await uwfStore.store.put(uwfStore.schemas.stepNode, {
+      start: startHash,
+      prev: null,
+      role: "roleA",
+      output: outputHash,
+      detail: null,
+      agent: "uwf-test",
+    });
+    await saveThreadsIndex(tmpDir, { ["01JTEST000000000000000C" as ThreadId]: stepHash as CasRef });
+
+    await expect(
+      cmdThreadRead(
+        tmpDir,
+        "01JTEST000000000000000C" as ThreadId,
+        THREAD_READ_DEFAULT_QUOTA,
+        "unknownhash0" as CasRef,
+        false,
+      ),
+    ).rejects.toThrow();
  });
 });
@@ -0,0 +1,367 @@
+import { mkdir, mkdtemp, rm, writeFile } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { createFsStore } from "@uncaged/json-cas-fs";
+import type { CasRef, WorkflowPayload } from "@uncaged/workflow-protocol";
+import { afterEach, beforeEach, describe, expect, test } from "vitest";
+import { stringify } from "yaml";
+import { cmdThreadStart } from "../commands/thread.js";
+import { registerUwfSchemas } from "../schemas.js";
+import type { UwfStore } from "../store.js";
+import { loadWorkflowRegistry, saveWorkflowRegistry } from "../store.js";
+
+// ── helpers ───────────────────────────────────────────────────────────────────
+
+async function makeUwfStore(storageRoot: string): Promise<UwfStore> {
+  const casDir = join(storageRoot, "cas");
+  await mkdir(casDir, { recursive: true });
+  const store = createFsStore(casDir);
+  const schemas = await registerUwfSchemas(store);
+  return { storageRoot, store, schemas };
+}
+
+async function storeWorkflow(uwf: UwfStore, name: string): Promise<CasRef> {
+  const payload: WorkflowPayload = {
+    name,
+    description: "Test workflow",
+    roles: {},
+    conditions: {},
+    graph: {},
+  };
+  return await uwf.store.put(uwf.schemas.workflow, payload);
+}
+
+async function createWorkflowYaml(name: string, version: string | null = null): Promise<string> {
+  const payload: WorkflowPayload = {
+    name,
+    description: version !== null ? `Test workflow (${version})` : "Test workflow",
+    roles: {},
+    conditions: {},
+    graph: {},
+  };
+  const yaml = stringify(payload);
+  return yaml;
+}
+
+// ── fixture ───────────────────────────────────────────────────────────────────
+
+let tmpDir: string;
+let storageRoot: string;
+let projectRoot: string;
+
+beforeEach(async () => {
+  tmpDir = await mkdtemp(join(tmpdir(), "cli-uwf-wf-resolve-test-"));
+  storageRoot = join(tmpDir, "storage");
+  projectRoot = join(tmpDir, "project");
+  await mkdir(storageRoot, { recursive: true });
+  await mkdir(projectRoot, { recursive: true });
+});
+
+afterEach(async () => {
+  await rm(tmpDir, { recursive: true, force: true });
+});
+
+// ── Strategy 1: CAS Hash Resolution ───────────────────────────────────────────
+
+describe("Strategy 1: CAS Hash Resolution", () => {
+  test("should resolve valid 13-char Crockford Base32 hash", async () => {
+    const uwf = await makeUwfStore(storageRoot);
+    const hash = await storeWorkflow(uwf, "test-workflow");
+
+    const result = await cmdThreadStart(storageRoot, hash, "test prompt", projectRoot);
+
+    expect(result.workflow).toBe(hash);
+    expect(result.thread).toMatch(/^[0-9A-HJKMNP-TV-Z]{26}$/);
+  });
+
+  test("should fail on invalid hash format (non-Crockford characters)", async () => {
+    await makeUwfStore(storageRoot);
+
+    await expect(
+      cmdThreadStart(storageRoot, "123456789ABCD", "prompt", projectRoot),
+    ).rejects.toThrow();
+  });
+
+  test("should fail on valid-format hash not present in CAS", async () => {
+    await makeUwfStore(storageRoot);
+    const fakeHash = "0000000000000"; // valid format, doesn't exist
+
+    await expect(cmdThreadStart(storageRoot, fakeHash, "prompt", projectRoot)).rejects.toThrow();
+  });
+
+  test("should reject 40-char hex hash (legacy format not supported)", async () => {
+    await makeUwfStore(storageRoot);
+    const hexHash = "a".repeat(40);
+
+    await expect(cmdThreadStart(storageRoot, hexHash, "prompt", projectRoot)).rejects.toThrow();
+  });
+});
+
+// ── Strategy 2: File Path Resolution ──────────────────────────────────────────
+
+describe("Strategy 2: File Path Resolution", () => {
+  test("should load workflow from absolute file path", async () => {
+    await makeUwfStore(storageRoot);
+    const yamlPath = join(tmpDir, "test-workflow.yaml");
+    await writeFile(yamlPath, await createWorkflowYaml("test-workflow"));
+
+    const result = await cmdThreadStart(storageRoot, yamlPath, "prompt", projectRoot);
+
+    expect(result.workflow).toMatch(/^[0-9A-HJKMNP-TV-Z]{13}$/);
+    const uwf = await makeUwfStore(storageRoot);
+    const node = uwf.store.get(result.workflow);
+    expect(node).not.toBeNull();
+    if (node !== null) {
+      expect((node.payload as WorkflowPayload).name).toBe("test-workflow");
+    }
+  });
+
+  test("should load workflow from relative file path", async () => {
+    await makeUwfStore(storageRoot);
+    const yamlPath = "test-workflow.yaml";
+    await writeFile(join(projectRoot, yamlPath), await createWorkflowYaml("test-workflow"));
+
+    const result = await cmdThreadStart(storageRoot, yamlPath, "prompt", projectRoot);
+
+    expect(result.workflow).toMatch(/^[0-9A-HJKMNP-TV-Z]{13}$/);
+  });
+
+  test("should fail when file path does not exist", async () => {
+    await makeUwfStore(storageRoot);
+
+    await expect(
+      cmdThreadStart(storageRoot, "./nonexistent.yaml", "prompt", projectRoot),
+    ).rejects.toThrow();
+  });
+
+  test("should fail on invalid YAML syntax in file", async () => {
+    await makeUwfStore(storageRoot);
+    const yamlPath = join(tmpDir, "bad-syntax.yaml");
+    await writeFile(yamlPath, "invalid: yaml: : :");
+
+    await expect(cmdThreadStart(storageRoot, yamlPath, "prompt", projectRoot)).rejects.toThrow();
+  });
+
+  test("should fail on valid YAML with invalid WorkflowPayload shape", async () => {
+    await makeUwfStore(storageRoot);
+    const yamlPath = join(tmpDir, "invalid-workflow.yaml");
+    await writeFile(yamlPath, "name: test\n# missing roles, conditions, and graph");
+
+    await expect(cmdThreadStart(storageRoot, yamlPath, "prompt", projectRoot)).rejects.toThrow();
+  });
+
+  test("should enforce filename matches workflow name", async () => {
+    await makeUwfStore(storageRoot);
+    const yamlPath = join(tmpDir, "solve-issue.yaml");
+    await writeFile(yamlPath, await createWorkflowYaml("wrong-name"));
+
+    await expect(cmdThreadStart(storageRoot, yamlPath, "prompt", projectRoot)).rejects.toThrow();
+  });
+});
+
+// ── Strategy 3: Local Discovery (Parent Traversal) ────────────────────────────
+
+describe("Strategy 3: Local Discovery", () => {
+  test("should find workflow in current directory .workflow/", async () => {
+    await makeUwfStore(storageRoot);
+    const workflowDir = join(projectRoot, ".workflow");
+    await mkdir(workflowDir, { recursive: true });
+    await writeFile(join(workflowDir, "solve-issue.yaml"), await createWorkflowYaml("solve-issue"));
+
+    const result = await cmdThreadStart(storageRoot, "solve-issue", "prompt", projectRoot);
+
+    expect(result.workflow).toMatch(/^[0-9A-HJKMNP-TV-Z]{13}$/);
+    const uwf = await makeUwfStore(storageRoot);
+    const node = uwf.store.get(result.workflow);
+    expect(node).not.toBeNull();
+    if (node !== null) {
+      expect((node.payload as WorkflowPayload).name).toBe("solve-issue");
+    }
+  });
+
+  test("should find workflow in parent directory .workflow/", async () => {
+    await makeUwfStore(storageRoot);
+    const workflowDir = join(projectRoot, ".workflow");
+    await mkdir(workflowDir, { recursive: true });
+    await writeFile(join(workflowDir, "solve-issue.yaml"), await createWorkflowYaml("solve-issue"));
+
+    const subdir = join(projectRoot, "packages", "cli-workflow", "src");
+    await mkdir(subdir, { recursive: true });
+
+    const result = await cmdThreadStart(storageRoot, "solve-issue", "prompt", subdir);
+
+    expect(result.workflow).toMatch(/^[0-9A-HJKMNP-TV-Z]{13}$/);
+  });
+
+  test("should stop at filesystem root when traversing", async () => {
+    await makeUwfStore(storageRoot);
+    const deepPath = join(tmpDir, "deep", "path", "that", "does", "not", "have", "workflow");
+    await mkdir(deepPath, { recursive: true });
+
+    await expect(cmdThreadStart(storageRoot, "nonexistent", "prompt", deepPath)).rejects.toThrow();
+  });
+
+  test("should prefer .workflow/ over .workflows/ directory", async () => {
+    await makeUwfStore(storageRoot);
+    const workflowDir = join(projectRoot, ".workflow");
+    const workflowsDir = join(projectRoot, ".workflows");
+    await mkdir(workflowDir, { recursive: true });
+    await mkdir(workflowsDir, { recursive: true });
+
+    await writeFile(
+      join(workflowDir, "solve-issue.yaml"),
+      await createWorkflowYaml("solve-issue", "1"),
+    );
+    await writeFile(
+      join(workflowsDir, "solve-issue.yaml"),
+      await createWorkflowYaml("solve-issue", "2"),
+    );
+
+    const result = await cmdThreadStart(storageRoot, "solve-issue", "prompt", projectRoot);
+
+    const uwf = await makeUwfStore(storageRoot);
+    const node = uwf.store.get(result.workflow);
+    expect(node).not.toBeNull();
+    if (node !== null) {
+      expect((node.payload as WorkflowPayload).description).toBe("Test workflow (1)");
+    }
+  });
+
+  test("should support .yml extension in local discovery", async () => {
+    await makeUwfStore(storageRoot);
+    const workflowDir = join(projectRoot, ".workflow");
+    await mkdir(workflowDir, { recursive: true });
+    await writeFile(join(workflowDir, "solve-issue.yml"), await createWorkflowYaml("solve-issue"));
+
+    const result = await cmdThreadStart(storageRoot, "solve-issue", "prompt", projectRoot);
+
+    expect(result.workflow).toMatch(/^[0-9A-HJKMNP-TV-Z]{13}$/);
+  });
+});
+
+// ── Strategy 4: Global Registry Fallback ──────────────────────────────────────
+
+describe("Strategy 4: Global Registry Resolution", () => {
+  test("should resolve workflow from global registry when not found locally", async () => {
+    const uwf = await makeUwfStore(storageRoot);
+    const hash = await storeWorkflow(uwf, "deploy-pipeline");
+    const registry = await loadWorkflowRegistry(storageRoot);
+    registry["deploy-pipeline"] = hash;
+    await saveWorkflowRegistry(storageRoot, registry);
+
+    const isolatedRoot = join(tmpDir, "isolated");
+    await mkdir(isolatedRoot, { recursive: true });
+
+    const result = await cmdThreadStart(storageRoot, "deploy-pipeline", "prompt", isolatedRoot);
+
+    expect(result.workflow).toBe(hash);
+  });
+
+  test("should fail when workflow not found in any strategy", async () => {
+    await makeUwfStore(storageRoot);
+
+    await expect(cmdThreadStart(storageRoot, "nonexistent", "prompt", tmpDir)).rejects.toThrow();
+  });
+});
+
+// ── Strategy Priority Order ───────────────────────────────────────────────────
+
+describe("Resolution Priority", () => {
+  test("should use explicit file path over local discovery", async () => {
+    await makeUwfStore(storageRoot);
+
+    // Setup: Create workflow in .workflow/ AND as explicit file
+    const workflowDir = join(projectRoot, ".workflow");
+    await mkdir(workflowDir, { recursive: true });
+    await writeFile(
+      join(workflowDir, "solve-issue.yaml"),
+      await createWorkflowYaml("solve-issue", "discovery"),
+    );
+
+    const explicitPath = join(projectRoot, "custom-solve-issue.yaml");
+    await writeFile(explicitPath, await createWorkflowYaml("custom-solve-issue", "explicit"));
+
+    // Execute with explicit path
+    const result = await cmdThreadStart(storageRoot, explicitPath, "prompt", projectRoot);
+
+    const uwf = await makeUwfStore(storageRoot);
+    const node = uwf.store.get(result.workflow);
+    expect(node).not.toBeNull();
+    if (node !== null) {
+      expect((node.payload as WorkflowPayload).description).toBe("Test workflow (explicit)");
+    }
+  });
+
+  test("should use local discovery over global registry", async () => {
+    const uwf = await makeUwfStore(storageRoot);
+
+    // Setup: Register globally
+    const globalHash = await storeWorkflow(uwf, "solve-issue");
+    const registry = await loadWorkflowRegistry(storageRoot);
+    registry["solve-issue"] = globalHash;
+    await saveWorkflowRegistry(storageRoot, registry);
+
+    // Setup: Create local .workflow/
+    const workflowDir = join(projectRoot, ".workflow");
+    await mkdir(workflowDir, { recursive: true });
+    const localYaml = await createWorkflowYaml("solve-issue", "local");
+    await writeFile(join(workflowDir, "solve-issue.yaml"), localYaml);
+
+    const result = await cmdThreadStart(storageRoot, "solve-issue", "prompt", projectRoot);
+
+    const uwf2 = await makeUwfStore(storageRoot);
+    const node = uwf2.store.get(result.workflow);
+    expect(node).not.toBeNull();
+    if (node !== null) {
+      expect((node.payload as WorkflowPayload).description).toBe("Test workflow (local)");
+    }
+  });
+});
+
+// ── Edge Cases ────────────────────────────────────────────────────────────────
+
+describe("Edge Cases", () => {
+  test("should treat '13-char-string.yaml' as file path, not CAS hash", async () => {
+    await makeUwfStore(storageRoot);
+    const fileName = "0123456789ABC.yaml"; // 13 chars + .yaml
+    await writeFile(join(projectRoot, fileName), await createWorkflowYaml("0123456789ABC"));
+
+    const result = await cmdThreadStart(storageRoot, fileName, "prompt", projectRoot);
+
+    expect(result.workflow).toMatch(/^[0-9A-HJKMNP-TV-Z]{13}$/);
+  });
+
+  test("should handle workflow names containing slashes as file paths", async () => {
+    await makeUwfStore(storageRoot);
+    const filePath = "subdir/solve-issue.yaml";
+    const fullPath = join(projectRoot, filePath);
+    await mkdir(join(projectRoot, "subdir"), { recursive: true });
+    await writeFile(fullPath, await createWorkflowYaml("solve-issue"));
+
+    const result = await cmdThreadStart(storageRoot, filePath, "prompt", projectRoot);
+
+    expect(result.workflow).toMatch(/^[0-9A-HJKMNP-TV-Z]{13}$/);
+  });
+
+  test("should handle absolute paths correctly", async () => {
+    await makeUwfStore(storageRoot);
+    const absPath = join(tmpDir, "abs-workflow.yaml");
+    await writeFile(absPath, await createWorkflowYaml("abs-workflow"));
+
+    const result = await cmdThreadStart(storageRoot, absPath, "prompt", projectRoot);
+
+    expect(result.workflow).toMatch(/^[0-9A-HJKMNP-TV-Z]{13}$/);
+  });
+
+  test("should fail on empty workflow ID", async () => {
+    await makeUwfStore(storageRoot);
+
+    await expect(cmdThreadStart(storageRoot, "", "prompt", projectRoot)).rejects.toThrow();
+  });
+
+  test("should fail on whitespace-only workflow ID", async () => {
+    await makeUwfStore(storageRoot);
+
+    await expect(cmdThreadStart(storageRoot, "   ", "prompt", projectRoot)).rejects.toThrow();
+  });
+});
@@ -0,0 +1,147 @@
+import { mkdir, readdir, readFile, rename, rm, writeFile } from "node:fs/promises";
+import { join } from "node:path";
+import type { RunningThreadItem, ThreadId } from "@uncaged/workflow-protocol";
+
+import type { RunningMarker } from "./types.js";
+
+/**
+ * Get the path to the running markers directory.
+ */
+export function getRunningDir(storageRoot: string): string {
+  return join(storageRoot, "running");
+}
+
+/**
+ * Get the path to a specific thread's marker file.
+ */
+export function getMarkerPath(storageRoot: string, threadId: ThreadId): string {
+  return join(getRunningDir(storageRoot), `${threadId}.json`);
+}
+
+/**
+ * Check if a PID is still running.
+ * Returns true if the process exists, false otherwise.
+ */
+export function isPidAlive(pid: number): boolean {
+  try {
+    // process.kill with signal 0 checks existence without killing
+    process.kill(pid, 0);
+    return true;
+  } catch {
+    // ESRCH means process doesn't exist
+    return false;
+  }
+}
+
+/**
+ * Create a marker file for a running thread.
+ * Writes to a temp file in the same directory, then atomically renames.
+ */
+export async function createMarker(storageRoot: string, marker: RunningMarker): Promise<void> {
+  const runningDir = getRunningDir(storageRoot);
+  await mkdir(runningDir, { recursive: true });
+
+  const markerPath = getMarkerPath(storageRoot, marker.thread);
+  const tempPath = join(runningDir, `.${marker.thread}-${process.pid}.tmp`);
+
+  const content = JSON.stringify(marker, null, 2);
+  await writeFile(tempPath, content, "utf8");
+  await rename(tempPath, markerPath);
+}
+
+/**
+ * Delete a marker file for a thread.
+ */
+export async function deleteMarker(storageRoot: string, threadId: ThreadId): Promise<void> {
+  const markerPath = getMarkerPath(storageRoot, threadId);
+  try {
+    await rm(markerPath);
+  } catch {
+    // Ignore errors if file doesn't exist
+  }
+}
+
+/**
+ * Read a marker file. Returns null if file doesn't exist or is invalid.
+ */
+export async function readMarker(
+  storageRoot: string,
+  threadId: ThreadId,
+): Promise<RunningMarker | null> {
+  const markerPath = getMarkerPath(storageRoot, threadId);
+  try {
+    const content = await readFile(markerPath, "utf8");
+    const marker = JSON.parse(content) as RunningMarker;
+    return marker;
+  } catch {
+    return null;
+  }
+}
+
+/**
+ * List all running threads, filtering out stale markers.
+ */
+export async function listRunningThreads(storageRoot: string): Promise<RunningThreadItem[]> {
+  const runningDir = getRunningDir(storageRoot);
+
+  let files: string[];
+  try {
+    files = await readdir(runningDir);
+  } catch {
+    // Directory doesn't exist or can't be read
+    return [];
+  }
+
+  const results: RunningThreadItem[] = [];
+
+  for (const filename of files) {
+    if (!filename.endsWith(".json")) {
+      continue;
+    }
+
+    const threadId = filename.slice(0, -5) as ThreadId;
+    const marker = await readMarker(storageRoot, threadId);
+
+    if (marker === null) {
+      // Invalid marker file
+      continue;
+    }
+
+    if (!isPidAlive(marker.pid)) {
+      // Stale marker - process no longer exists
+      await deleteMarker(storageRoot, threadId);
+      continue;
+    }
+
+    results.push({
+      thread: marker.thread,
+      workflow: marker.workflow,
+      pid: marker.pid,
+      startedAt: marker.startedAt,
+    });
+  }
+
+  return results;
+}
+
+/**
+ * Check if a thread is currently executing in the background.
+ * Returns the marker if running, null otherwise.
+ */
+export async function isThreadRunning(
+  storageRoot: string,
+  threadId: ThreadId,
+): Promise<RunningMarker | null> {
+  const marker = await readMarker(storageRoot, threadId);
+  if (marker === null) {
+    return null;
+  }
+
+  if (!isPidAlive(marker.pid)) {
+    // Stale marker
+    await deleteMarker(storageRoot, threadId);
+    return null;
+  }
+
+  return marker;
+}
@@ -0,0 +1,11 @@
+export {
+  createMarker,
+  deleteMarker,
+  getMarkerPath,
+  getRunningDir,
+  isPidAlive,
+  isThreadRunning,
+  listRunningThreads,
+  readMarker,
+} from "./background.js";
+export type { RunningMarker } from "./types.js";
@@ -0,0 +1,9 @@
+import type { CasRef, ThreadId } from "@uncaged/workflow-protocol";
+
+/** Marker file stored at ~/.uncaged/workflow/running/<thread-id>.json */
+export type RunningMarker = {
+  thread: ThreadId;
+  workflow: CasRef;
+  pid: number;
+  startedAt: number;
+};
@@ -1,8 +1,7 @@
 #!/usr/bin/env bun

-import type { ThreadId } from "@uncaged/workflow-protocol";
+import type { CasRef, ThreadId } from "@uncaged/workflow-protocol";
 import { Command } from "commander";
-import { stringify as yamlStringify } from "yaml";
 import {
  cmdCasGet,
  cmdCasHas,
@@ -17,19 +16,19 @@ import {
 import { cmdLogClean, cmdLogList, cmdLogShow } from "./commands/log.js";
 import { cmdSetup, cmdSetupInteractive } from "./commands/setup.js";
 import { cmdSkillCli } from "./commands/skill.js";
+import { cmdStepFork, cmdStepList, cmdStepShow } from "./commands/step.js";
 import {
-  cmdThreadFork,
-  cmdThreadKill,
+  cmdThreadCancel,
+  cmdThreadExec,
  cmdThreadList,
  cmdThreadRead,
  cmdThreadShow,
  cmdThreadStart,
-  cmdThreadStep,
-  cmdThreadStepDetails,
-  cmdThreadSteps,
+  cmdThreadStop,
  THREAD_READ_DEFAULT_QUOTA,
+  type ThreadStatus,
 } from "./commands/thread.js";
-import { cmdWorkflowList, cmdWorkflowPut, cmdWorkflowShow } from "./commands/workflow.js";
+import { cmdWorkflowAdd, cmdWorkflowList, cmdWorkflowShow } from "./commands/workflow.js";
 import { formatOutput, type OutputFormat } from "./format.js";
 import { resolveStorageRoot } from "./store.js";

@@ -52,20 +51,27 @@ const program = new Command();
 const pkg = await import("../package.json", { with: { type: "json" } });
 program
  .name("uwf")
-  .description("Stateless workflow CLI")
+  .description(
+    "Stateless workflow CLI\n\n" +
+      "Four-layer architecture:\n" +
+      "  workflow → thread → step → turn\n" +
+      "  模板定义   执行实例   单步结果   agent内部交互",
+  )
  .version(pkg.default.version, "-V, --version");
 program.option("--format <fmt>", "Output format: json or yaml", "json");

-const workflow = program.command("workflow").description("Workflow registry and CAS");
+const workflow = program
+  .command("workflow")
+  .description("Workflow definitions (layer 1: templates)");

 workflow
-  .command("put")
+  .command("add")
  .description("Register a workflow from YAML")
  .argument("<file>", "Workflow YAML file")
  .action((file: string) => {
    const storageRoot = resolveStorageRoot();
    runAction(async () => {
-      const result = await cmdWorkflowPut(storageRoot, file);
+      const result = await cmdWorkflowAdd(storageRoot, file);
      writeOutput(result);
    });
  });
@@ -93,7 +99,7 @@ workflow
    });
  });

-const thread = program.command("thread").description("Thread lifecycle and execution");
+const thread = program.command("thread").description("Thread execution (layer 2: instances)");

 thread
  .command("start")
@@ -109,24 +115,46 @@ thread
  });

 thread
-  .command("step")
+  .command("exec")
  .description("Execute one or more steps")
  .argument("<thread-id>", "Thread ULID")
  .option("--agent <cmd>", "Override agent command")
  .option("-c, --count <number>", "Number of steps to run (default: 1)")
-  .action((threadId: string, opts: { agent: string | undefined; count: string | undefined }) => {
-    const storageRoot = resolveStorageRoot();
-    runAction(async () => {
-      const agentOverride = opts.agent ?? null;
-      const count = opts.count !== undefined ? Number(opts.count) : 1;
-      const results = await cmdThreadStep(storageRoot, threadId, agentOverride, count);
-      if (results.length === 1) {
-        writeOutput(results[0]);
-      } else {
-        writeOutput(results);
-      }
-    });
-  });
+  .option("--background", "Run in background and return immediately")
+  .option("--_background-worker", "Internal flag for background worker process", false)
+  .action(
+    (
+      threadId: string,
+      opts: {
+        agent: string | undefined;
+        count: string | undefined;
+        background: boolean;
+        _backgroundWorker: boolean;
+      },
+    ) => {
+      const storageRoot = resolveStorageRoot();
+      runAction(async () => {
+        const agentOverride = opts.agent ?? null;
+        const count = opts.count !== undefined ? Number(opts.count) : 1;
+        const background = opts.background ?? false;
+        const backgroundWorker = opts._backgroundWorker ?? false;
+
+        const results = await cmdThreadExec(
+          storageRoot,
+          threadId,
+          agentOverride,
+          count,
+          background,
+          backgroundWorker,
+        );
+        if (results.length === 1) {
+          writeOutput(results[0]);
+        } else {
+          writeOutput(results);
+        }
+      });
+    },
+  );

 thread
  .command("show")
@@ -142,36 +170,49 @@ thread

 thread
  .command("list")
-  .description("List active threads")
-  .option("--all", "Include archived threads")
-  .action((opts: { all: boolean }) => {
+  .description("List threads")
+  .option("--status <status>", "Filter by status: idle, running, or completed")
+  .action((opts: { status: string | undefined }) => {
    const storageRoot = resolveStorageRoot();
    runAction(async () => {
-      const result = await cmdThreadList(storageRoot, opts.all);
+      const validStatuses: ThreadStatus[] = ["idle", "running", "completed"];
+      let statusFilter: ThreadStatus | null = null;
+
+      if (opts.status !== undefined) {
+        if (!validStatuses.includes(opts.status as ThreadStatus)) {
+          process.stderr.write(
+            `Invalid status: ${opts.status}. Must be one of: idle, running, completed\n`,
+          );
+          process.exit(1);
+        }
+        statusFilter = opts.status as ThreadStatus;
+      }
+
+      const result = await cmdThreadList(storageRoot, statusFilter);
      writeOutput(result);
    });
  });

 thread
-  .command("kill")
-  .description("Terminate and archive a thread")
+  .command("stop")
+  .description("Stop background execution of a thread (keep thread active)")
  .argument("<thread-id>", "Thread ULID")
  .action((threadId: string) => {
    const storageRoot = resolveStorageRoot();
    runAction(async () => {
-      const result = await cmdThreadKill(storageRoot, threadId);
+      const result = await cmdThreadStop(storageRoot, threadId);
      writeOutput(result);
    });
  });

 thread
-  .command("steps")
-  .description("List all steps in a thread")
+  .command("cancel")
+  .description("Cancel a thread (stop execution and move to history)")
  .argument("<thread-id>", "Thread ULID")
  .action((threadId: string) => {
    const storageRoot = resolveStorageRoot();
    runAction(async () => {
-      const result = await cmdThreadSteps(storageRoot, threadId);
+      const result = await cmdThreadCancel(storageRoot, threadId);
      writeOutput(result);
    });
  });
@@ -205,28 +246,141 @@ thread
    },
  );

-thread
+const step = program.command("step").description("Step results (layer 3: single cycle)");
+
+step
+  .command("list")
+  .description("List all steps in a thread")
+  .argument("<thread-id>", "Thread ULID")
+  .action((threadId: string) => {
+    const storageRoot = resolveStorageRoot();
+    runAction(async () => {
+      const result = await cmdStepList(storageRoot, threadId);
+      writeOutput(result);
+    });
+  });
+
+step
+  .command("show")
+  .description("Show details of a specific step")
+  .argument("<step-hash>", "CAS hash of the StepNode")
+  .action((stepHash: string) => {
+    const storageRoot = resolveStorageRoot();
+    runAction(async () => {
+      const detail = await cmdStepShow(storageRoot, stepHash as CasRef);
+      writeOutput(detail);
+    });
+  });
+
+// step read is not yet registered (half-baked, see step.ts cmdStepRead)
+
+step
  .command("fork")
  .description("Fork a thread from a specific step")
  .argument("<step-hash>", "CAS hash of the StartNode or StepNode to fork from")
  .action((stepHash: string) => {
    const storageRoot = resolveStorageRoot();
    runAction(async () => {
-      const result = await cmdThreadFork(storageRoot, stepHash);
+      const result = await cmdStepFork(storageRoot, stepHash as CasRef);
      writeOutput(result);
    });
  });

+// ── Deprecation Handlers ──────────────────────────────────────────────────────
+// These commands have been removed. Show helpful error messages.
+
+workflow
+  .command("put")
+  .description("[DEPRECATED] Use 'workflow add' instead")
+  .argument("<file>", "Workflow YAML file")
+  .action(() => {
+    process.stderr.write(`Error: Command 'workflow put' has been removed.
+Use 'workflow add' instead.
+
+For more information, see: uwf help workflow add
+`);
+    process.exit(1);
+  });
+
+thread
+  .command("step")
+  .description("[DEPRECATED] Use 'thread exec' instead")
+  .argument("<thread-id>", "Thread ULID")
+  .allowUnknownOption()
+  .action(() => {
+    process.stderr.write(`Error: Command 'thread step' has been removed.
+Use 'thread exec' instead.
+
+For more information, see: uwf help thread exec
+`);
+    process.exit(1);
+  });
+
+thread
+  .command("steps")
+  .description("[DEPRECATED] Use 'step list' instead")
+  .argument("<thread-id>", "Thread ULID")
+  .action(() => {
+    process.stderr.write(`Error: Command 'thread steps' has been removed.
+Use 'step list' instead.
+
+For more information, see: uwf help step list
+`);
+    process.exit(1);
+  });
+
 thread
  .command("step-details")
-  .description("Dump the full detail node of a step as YAML")
-  .argument("<step-hash>", "CAS hash of the StepNode")
-  .action((stepHash: string) => {
-    const storageRoot = resolveStorageRoot();
-    runAction(async () => {
-      const detail = await cmdThreadStepDetails(storageRoot, stepHash);
-      process.stdout.write(yamlStringify(detail));
-    });
+  .description("[DEPRECATED] Use 'step show' instead")
+  .argument("<step-hash>", "Step hash")
+  .action(() => {
+    process.stderr.write(`Error: Command 'thread step-details' has been removed.
+Use 'step show' instead.
+
+For more information, see: uwf help step show
+`);
+    process.exit(1);
+  });
+
+thread
+  .command("fork")
+  .description("[DEPRECATED] Use 'step fork' instead")
+  .argument("<step-hash>", "Step hash")
+  .action(() => {
+    process.stderr.write(`Error: Command 'thread fork' has been removed.
+Use 'step fork' instead.
+
+For more information, see: uwf help step fork
+`);
+    process.exit(1);
+  });
+
+thread
+  .command("kill")
+  .description("[DEPRECATED] Use 'thread stop' or 'thread cancel' instead")
+  .argument("<thread-id>", "Thread ULID")
+  .action(() => {
+    process.stderr.write(`Error: Command 'thread kill' has been removed.
+Use 'thread stop' to stop background execution (keep thread active),
+or 'thread cancel' to cancel and archive the thread.
+
+For more information, see:
+  uwf help thread stop
+  uwf help thread cancel
+`);
+    process.exit(1);
+  });
+
+thread
+  .command("running")
+  .description("[DEPRECATED] Use 'thread list --status running' instead")
+  .action(() => {
+    process.stderr.write(`Error: Command 'thread running' has been removed.
+Use 'thread list --status running' instead.
+
+For more information, see: uwf help thread list
+`);
+    process.exit(1);
  });

 const skill = program.command("skill").description("Built-in skill references for agents");
@@ -1,4 +1,4 @@
-import { existsSync, mkdirSync, readFileSync, writeFileSync } from "node:fs";
+import { existsSync, mkdirSync, readdirSync, readFileSync, statSync, writeFileSync } from "node:fs";
 import { join } from "node:path";
 import { stdin as input, stdout as output } from "node:process";
 import { createInterface } from "node:readline/promises";
@@ -137,6 +137,182 @@ function apiKeyEnvName(providerName: string): string {
  return `${providerName.toUpperCase().replace(/[^A-Z0-9]/g, "_")}_API_KEY`;
 }

+// ──────────────────────────────────────────────────────────────────────────────
+// Extracted helpers — _discoverAgents
+// ──────────────────────────────────────────────────────────────────────────────
+
+/**
+ * Scans directories from a PATH string for uwf-* executables.
+ */
+export async function _searchPathDirs(pathEnv: string): Promise<string[]> {
+  if (!pathEnv) return [];
+  const dirs = pathEnv.split(":").filter((d) => d.length > 0);
+  const agents = new Set<string>();
+  for (const dir of dirs) {
+    _scanDirForAgents(dir, agents);
+  }
+  return Array.from(agents).sort();
+}
+
+function _scanDirForAgents(dir: string, agents: Set<string>): void {
+  try {
+    if (!existsSync(dir)) return;
+    const entries = readdirSync(dir);
+    for (const entry of entries) {
+      if (!entry.startsWith("uwf-") || entry === "uwf") continue;
+      if (_isExecutableFile(join(dir, entry))) {
+        agents.add(entry);
+      }
+    }
+  } catch {
+    // Skip inaccessible directories
+  }
+}
+
+function _isExecutableFile(fullPath: string): boolean {
+  try {
+    const s = statSync(fullPath);
+    return s.isFile() && (s.mode & 0o111) !== 0;
+  } catch {
+    return false;
+  }
+}
+
+/**
+ * Parses the stdout of `which -a` into sorted unique basenames.
+ */
+export function _parseWhichOutput(text: string): string[] {
+  if (!text) return [];
+  const agents = new Set<string>();
+  for (const line of text.trim().split("\n")) {
+    if (!line) continue;
+    const basename = line.split("/").pop() ?? "";
+    if (basename.startsWith("uwf-") && basename !== "uwf") {
+      agents.add(basename);
+    }
+  }
+  return Array.from(agents).sort();
+}
+
+/**
+ * Discover uwf-* agent binaries in PATH.
+ * Returns sorted list of binary names (e.g., ["uwf-hermes", "uwf-claude-code"]).
+ */
+export async function _discoverAgents(): Promise<string[]> {
+  try {
+    const agents = await _tryWhichDiscovery();
+    if (agents !== null) return agents;
+    return await _searchPathDirs(process.env.PATH ?? "");
+  } catch {
+    return [];
+  }
+}
+
+async function _tryWhichDiscovery(): Promise<string[] | null> {
+  try {
+    const proc = Bun.spawn(["which", "-a", "uwf-hermes", "uwf-claude-code", "uwf-cursor"], {
+      stdout: "pipe",
+      stderr: "pipe",
+    });
+    const text = await new Response(proc.stdout).text();
+    await proc.exited;
+    if (proc.exitCode !== 0) return null;
+    return _parseWhichOutput(text);
+  } catch {
+    return null;
+  }
+}
+
+// ──────────────────────────────────────────────────────────────────────────────
+// Extracted helpers — onData closure (promptSecret)
+// ──────────────────────────────────────────────────────────────────────────────
+
+/** Returns true for newline, carriage return, or EOF (EOT). */
+export function _isTerminator(c: string): boolean {
+  return c === "\n" || c === "\r" || c === "";
+}
+
+/** Returns true for DEL or backspace. */
+export function _isBackspace(c: string): boolean {
+  return c === "" || c === "\b";
+}
+
+// ──────────────────────────────────────────────────────────────────────────────
+// Extracted helpers — cmdSetupInteractive
+// ──────────────────────────────────────────────────────────────────────────────
+
+type ProviderEntry = { name: string; label: string; baseUrl: string };
+
+/** Prints the numbered provider list and custom option to stdout. */
+export function _printProviderMenu(providers: readonly ProviderEntry[]): void {
+  const numWidth = String(providers.length + 1).length;
+  for (let i = 0; i < providers.length; i++) {
+    const p = providers[i];
+    if (!p) continue;
+    const num = String(i + 1).padStart(numWidth);
+    console.log(`  ${num}) ${p.label.padEnd(28)} ${p.baseUrl}`);
+  }
+  const customNum = String(providers.length + 1).padStart(numWidth);
+  console.log(`  ${customNum}) Custom (enter name and URL manually)\n`);
+}
+
+/** Resolves a numeric choice string to a preset provider, or null for custom/invalid. */
+export function _resolveProviderChoice(
+  choice: string,
+  providers: readonly ProviderEntry[],
+): { providerName: string; baseUrl: string } | null {
+  const n = Number.parseInt(choice, 10);
+  if (Number.isNaN(n) || n < 1 || n > providers.length) return null;
+  const p = providers[n - 1];
+  if (!p) return null;
+  return { providerName: p.name, baseUrl: p.baseUrl };
+}
+
+/** Resolves numeric index or literal model name to a model string. */
+export function _resolveModelChoice(input: string, models: string[]): string {
+  const n = Number.parseInt(input, 10);
+  if (!Number.isNaN(n) && n >= 1 && n <= models.length) {
+    return models[n - 1] ?? input;
+  }
+  return input;
+}
+
+/** Prints the multi-column model list to stdout. */
+export function _printModelMenu(models: string[], termCols: number): void {
+  const nw = String(models.length).length;
+  const maxLen = models.reduce((m, s) => Math.max(m, s.length), 0);
+  const colWidth = nw + 2 + maxLen + 4;
+  const cols = Math.max(1, Math.floor(termCols / colWidth));
+  const rows = Math.ceil(models.length / cols);
+  for (let r = 0; r < rows; r++) {
+    let line = "";
+    for (let c = 0; c < cols; c++) {
+      const idx = c * rows + r;
+      if (idx >= models.length) break;
+      const num = String(idx + 1).padStart(nw);
+      const name = (models[idx] ?? "").padEnd(maxLen);
+      line += `  ${num}) ${name}  `;
+    }
+    console.log(line.trimEnd());
+  }
+}
+
+type ValidationResult = { ok: boolean; error: string | null };
+
+/** Prints the model validation result to stdout. */
+export function _printValidationResult(validation: ValidationResult): void {
+  if (validation.ok) {
+    console.log("✓ Model verified — connection successful.\n");
+  } else {
+    console.log(`\n⚠ Warning: Could not reach model — ${validation.error}`);
+    console.log(
+      "  Config saved, but you may want to try a different model or check your API key.\n",
+    );
+  }
+}
+
+// ──────────────────────────────────────────────────────────────────────────────
+
 /**
 * Merge setup args into config.yaml structure. Non-destructive — preserves existing entries.
 */
@@ -212,6 +388,46 @@ export async function cmdSetup(args: SetupArgs): Promise<Record<string, unknown>
  };
 }

+type SecretState = {
+  buf: string;
+  rawWasSet: boolean;
+  resolve: (value: string) => void;
+  onData: (chunk: string) => void;
+};
+
+function _handleSecretTerminator(state: SecretState): void {
+  if (process.stdin.isTTY) process.stdin.setRawMode(state.rawWasSet);
+  process.stdin.pause();
+  process.stdin.removeListener("data", state.onData);
+  process.stdout.write("\n");
+  state.resolve(state.buf.trim());
+}
+
+function _handleSecretBackspace(state: SecretState): void {
+  if (state.buf.length > 0) {
+    state.buf = state.buf.slice(0, -1);
+    process.stdout.write("\b \b");
+  }
+}
+
+function _handleSecretChar(c: string, state: SecretState): boolean {
+  if (_isTerminator(c)) {
+    _handleSecretTerminator(state);
+    return true;
+  }
+  if (_isBackspace(c)) {
+    _handleSecretBackspace(state);
+    return false;
+  }
+  if (c === "") {
+    if (process.stdin.isTTY) process.stdin.setRawMode(state.rawWasSet);
+    process.exit(130);
+  }
+  state.buf += c;
+  process.stdout.write("*");
+  return false;
+}
+
 /** Read a line with terminal echo disabled (for secrets). */
 async function promptSecret(label: string): Promise<string> {
  process.stdout.write(label);
@@ -223,33 +439,13 @@ async function promptSecret(label: string): Promise<string> {
    process.stdin.resume();
    process.stdin.setEncoding("utf8");

-    let buf = "";
-    const onData = (chunk: string) => {
+    const state: SecretState = { buf: "", rawWasSet, resolve, onData: () => {} };
+    state.onData = (chunk: string) => {
      for (const c of chunk.toString()) {
-        if (c === "\n" || c === "\r" || c === "\u0004") {
-          if (process.stdin.isTTY) process.stdin.setRawMode(rawWasSet);
-          process.stdin.pause();
-          process.stdin.removeListener("data", onData);
-          process.stdout.write("\n");
-          resolve(buf.trim());
-          return;
-        }
-        if (c === "\u007F" || c === "\b") {
-          if (buf.length > 0) {
-            buf = buf.slice(0, -1);
-            process.stdout.write("\b \b");
-          }
-          continue;
-        }
-        if (c === "\u0003") {
-          if (process.stdin.isTTY) process.stdin.setRawMode(rawWasSet);
-          process.exit(130);
-        }
-        buf += c;
-        process.stdout.write("*");
+        if (_handleSecretChar(c, state)) return;
      }
    };
-    process.stdin.on("data", onData);
+    process.stdin.on("data", state.onData);
  });
 }

@@ -275,6 +471,56 @@ async function fetchModels(baseUrl: string, apiKey: string): Promise<string[]> {
  }
 }

+async function _promptProviderSelection(
+  rl: ReturnType<typeof createInterface>,
+): Promise<{ providerName: string; baseUrl: string }> {
+  console.log("Select a provider:\n");
+  _printProviderMenu(PRESET_PROVIDERS);
+
+  const choice = (await rl.question(`Choose [1-${PRESET_PROVIDERS.length + 1}]: `)).trim();
+  const choiceNum = Number.parseInt(choice, 10);
+  if (Number.isNaN(choiceNum) || choiceNum < 1 || choiceNum > PRESET_PROVIDERS.length + 1) {
+    throw new Error(`Invalid choice: ${choice}`);
+  }
+
+  const preset = _resolveProviderChoice(choice, PRESET_PROVIDERS);
+  if (preset) {
+    const selected = PRESET_PROVIDERS[choiceNum - 1];
+    if (selected) {
+      console.log(`\n  → ${selected.label} (${selected.baseUrl})\n`);
+    }
+    return preset;
+  }
+
+  const providerName = (await rl.question("Provider name (e.g. my-proxy): ")).trim();
+  if (!providerName) throw new Error("Provider name required");
+  const baseUrl = (await rl.question("OpenAI-compatible API base URL: ")).trim();
+  if (!baseUrl) throw new Error("Base URL required");
+  return { providerName, baseUrl };
+}
+
+async function _promptModelSelection(
+  rl: ReturnType<typeof createInterface>,
+  baseUrl: string,
+  apiKey: string,
+): Promise<string> {
+  console.log("\nFetching available models...");
+  const models = await fetchModels(baseUrl, apiKey);
+
+  if (models.length === 0) {
+    console.log("Could not fetch models. Enter model name manually.");
+    const model = (await rl.question("Default model (e.g. qwen-plus, gpt-4o): ")).trim();
+    if (!model) throw new Error("Model required");
+    return model;
+  }
+  console.log(`\nAvailable models (${models.length}):\n`);
+  _printModelMenu(models, process.stdout.columns || 100);
+  console.log(`\nChoose a number, or type a model name directly.`);
+  const modelInput = (await rl.question(`Default model [1-${models.length}]: `)).trim();
+  if (!modelInput) throw new Error("Model required");
+  return _resolveModelChoice(modelInput, models);
+}
+
 /**
 * Interactive setup — prompts user for provider, API key, model.
 */
@@ -284,39 +530,7 @@ export async function cmdSetupInteractive(storageRoot: string): Promise<Record<s
  try {
    console.log("Configure LLM provider for uwf workflow agents.\n");

-    // 1. Provider selection
-    const numWidth = String(PRESET_PROVIDERS.length + 1).length;
-    console.log("Select a provider:\n");
-    for (let i = 0; i < PRESET_PROVIDERS.length; i++) {
-      const p = PRESET_PROVIDERS[i];
-      if (!p) continue;
-      const num = String(i + 1).padStart(numWidth);
-      console.log(`  ${num}) ${p.label.padEnd(28)} ${p.baseUrl}`);
-    }
-    const customNum = String(PRESET_PROVIDERS.length + 1).padStart(numWidth);
-    console.log(`  ${customNum}) Custom (enter name and URL manually)\n`);
-
-    const choice = (await rl.question(`Choose [1-${PRESET_PROVIDERS.length + 1}]: `)).trim();
-    const choiceNum = Number.parseInt(choice, 10);
-    if (Number.isNaN(choiceNum) || choiceNum < 1 || choiceNum > PRESET_PROVIDERS.length + 1) {
-      throw new Error(`Invalid choice: ${choice}`);
-    }
-
-    let providerName: string;
-    let baseUrl: string;
-
-    if (choiceNum <= PRESET_PROVIDERS.length) {
-      const selected = PRESET_PROVIDERS[choiceNum - 1];
-      if (!selected) throw new Error("Invalid selection");
-      providerName = selected.name;
-      baseUrl = selected.baseUrl;
-      console.log(`\n  → ${selected.label} (${selected.baseUrl})\n`);
-    } else {
-      providerName = (await rl.question("Provider name (e.g. my-proxy): ")).trim();
-      if (!providerName) throw new Error("Provider name required");
-      baseUrl = (await rl.question("OpenAI-compatible API base URL: ")).trim();
-      if (!baseUrl) throw new Error("Base URL required");
-    }
+    const { providerName, baseUrl } = await _promptProviderSelection(rl);

    // 2. API key
    rl.close();
@@ -325,47 +539,8 @@ export async function cmdSetupInteractive(storageRoot: string): Promise<Record<s

    // 3. Model selection
    const rl2 = createInterface({ input, output });
-    console.log("\nFetching available models...");
-    const models = await fetchModels(baseUrl, apiKey);
-
-    let model: string;
-    if (models.length > 0) {
-      console.log(`\nAvailable models (${models.length}):\n`);
-      const nw = String(models.length).length;
-      // Multi-column layout
-      const maxLen = models.reduce((m, s) => Math.max(m, s.length), 0);
-      const colWidth = nw + 2 + maxLen + 4; // "  N) name    "
-      const termCols = process.stdout.columns || 100;
-      const cols = Math.max(1, Math.floor(termCols / colWidth));
-      const rows = Math.ceil(models.length / cols);
-      for (let r = 0; r < rows; r++) {
-        let line = "";
-        for (let c = 0; c < cols; c++) {
-          const idx = c * rows + r;
-          if (idx >= models.length) break;
-          const num = String(idx + 1).padStart(nw);
-          const name = (models[idx] ?? "").padEnd(maxLen);
-          line += `  ${num}) ${name}  `;
-        }
-        console.log(line.trimEnd());
-      }
-      console.log(`\nChoose a number, or type a model name directly.`);
-      const modelInput = (await rl2.question(`Default model [1-${models.length}]: `)).trim();
-      if (!modelInput) throw new Error("Model required");
-      const modelNum = Number.parseInt(modelInput, 10);
-      if (!Number.isNaN(modelNum) && modelNum >= 1 && modelNum <= models.length) {
-        model = models[modelNum - 1] ?? modelInput;
-      } else {
-        model = modelInput;
-      }
-    } else {
-      console.log("Could not fetch models. Enter model name manually.");
-      model = (await rl2.question("Default model (e.g. qwen-plus, gpt-4o): ")).trim();
-      if (!model) throw new Error("Model required");
-    }
-
+    const model = await _promptModelSelection(rl2, baseUrl, apiKey);
    rl2.close();
-
    console.log(`  → ${providerName}/${model}\n`);

    const setupResult = await cmdSetup({
@@ -378,17 +553,8 @@ export async function cmdSetupInteractive(storageRoot: string): Promise<Record<s

    // Show validation result
    if (setupResult.validation && typeof setupResult.validation === "object") {
-      const v = setupResult.validation as { ok: boolean; error?: string };
-      if (v.ok) {
-        console.log("✓ Model verified — connection successful.\n");
-      } else {
-        console.log(`\n⚠ Warning: Could not reach model — ${v.error}`);
-        console.log(
-          "  Config saved, but you may want to try a different model or check your API key.\n",
-        );
-      }
+      _printValidationResult(setupResult.validation as ValidationResult);
    }
-
    console.log("Setup complete! Get started:\n");
    console.log("  uwf workflow put <workflow.yaml>   Register a workflow");
    console.log('  uwf thread start <name> -p "..."   Start a thread');
@@ -0,0 +1,227 @@
+import type { Store as CasStore, JSONSchema } from "@uncaged/json-cas";
+import { getSchema } from "@uncaged/json-cas";
+import type {
+  CasRef,
+  StartNodePayload,
+  StepNodePayload,
+  ThreadId,
+} from "@uncaged/workflow-protocol";
+import { loadThreadsIndex, type UwfStore } from "../store.js";
+
+type ChainState = {
+  startHash: CasRef;
+  start: StartNodePayload;
+  stepsNewestFirst: StepNodePayload[];
+  headIsStart: boolean;
+};
+
+type OrderedStepItem = {
+  hash: CasRef;
+  payload: StepNodePayload;
+  timestamp: number;
+};
+
+function fail(message: string): never {
+  process.stderr.write(`${message}\n`);
+  process.exit(1);
+}
+
+function walkChain(uwf: UwfStore, headHash: CasRef): ChainState {
+  const headNode = uwf.store.get(headHash);
+  if (headNode === null) {
+    fail(`CAS node not found: ${headHash}`);
+  }
+
+  if (headNode.type === uwf.schemas.startNode) {
+    return {
+      startHash: headHash,
+      start: headNode.payload as StartNodePayload,
+      stepsNewestFirst: [],
+      headIsStart: true,
+    };
+  }
+
+  if (headNode.type !== uwf.schemas.stepNode) {
+    fail(`head ${headHash} is not a StartNode or StepNode`);
+  }
+
+  const stepsNewestFirst: StepNodePayload[] = [];
+  let hash: CasRef | null = headHash;
+
+  while (hash !== null) {
+    const node = uwf.store.get(hash);
+    if (node === null) {
+      fail(`CAS node not found while walking chain: ${hash}`);
+    }
+    if (node.type !== uwf.schemas.stepNode) {
+      break;
+    }
+    const payload = node.payload as StepNodePayload;
+    stepsNewestFirst.push(payload);
+    hash = payload.prev;
+  }
+
+  const newest = stepsNewestFirst[0];
+  if (newest === undefined) {
+    fail(`empty step chain at head ${headHash}`);
+  }
+
+  const startNode = uwf.store.get(newest.start);
+  if (startNode === null || startNode.type !== uwf.schemas.startNode) {
+    fail(`StartNode not found: ${newest.start}`);
+  }
+
+  return {
+    startHash: newest.start,
+    start: startNode.payload as StartNodePayload,
+    stepsNewestFirst,
+    headIsStart: false,
+  };
+}
+
+function expandOutput(uwf: UwfStore, outputRef: CasRef): unknown {
+  const node = uwf.store.get(outputRef);
+  if (node === null) {
+    return {};
+  }
+  return node.payload;
+}
+
+/**
+ * Recursively expand all cas_ref fields in a CAS node's payload,
+ * replacing hash strings with the referenced node's expanded payload.
+ */
+function expandDeep(store: CasStore, hash: CasRef, visited?: Set<string>): unknown {
+  const seen = visited ?? new Set<string>();
+  if (seen.has(hash)) return hash; // cycle guard
+  seen.add(hash);
+
+  const node = store.get(hash);
+  if (node === null) return hash;
+
+  const schema = getSchema(store, node.type);
+  if (schema === null) return node.payload;
+
+  return expandValue(store, schema, node.payload, seen);
+}
+
+function expandCasRefField(store: CasStore, value: unknown, visited: Set<string>): unknown {
+  if (typeof value === "string") {
+    return expandDeep(store, value as CasRef, visited);
+  }
+  return value;
+}
+
+function expandAnyOfField(
+  store: CasStore,
+  schema: JSONSchema,
+  value: unknown,
+  visited: Set<string>,
+): unknown {
+  if (!Array.isArray(schema.anyOf)) return value;
+  for (const sub of schema.anyOf as JSONSchema[]) {
+    if (sub.format === "cas_ref" && typeof value === "string") {
+      return expandDeep(store, value as CasRef, visited);
+    }
+  }
+  return value;
+}
+
+function expandArrayField(
+  store: CasStore,
+  schema: JSONSchema,
+  value: unknown,
+  visited: Set<string>,
+): unknown {
+  if (!schema.items || !Array.isArray(value)) return value;
+  const itemSchema = schema.items as JSONSchema;
+  return (value as unknown[]).map((item) => expandValue(store, itemSchema, item, visited));
+}
+
+function expandObjectField(
+  store: CasStore,
+  schema: JSONSchema,
+  value: unknown,
+  visited: Set<string>,
+): unknown {
+  if (value === null || typeof value !== "object" || Array.isArray(value) || !schema.properties) {
+    return value;
+  }
+  const props = schema.properties as Record<string, JSONSchema>;
+  const obj = value as Record<string, unknown>;
+  const result: Record<string, unknown> = {};
+  for (const [key, val] of Object.entries(obj)) {
+    const propSchema = props[key];
+    result[key] = propSchema ? expandValue(store, propSchema, val, visited) : val;
+  }
+  return result;
+}
+
+function expandValue(
+  store: CasStore,
+  schema: JSONSchema,
+  value: unknown,
+  visited: Set<string>,
+): unknown {
+  if (schema.format === "cas_ref") return expandCasRefField(store, value, visited);
+  if (Array.isArray(schema.anyOf)) return expandAnyOfField(store, schema, value, visited);
+  if (schema.type === "array") return expandArrayField(store, schema, value, visited);
+  return expandObjectField(store, schema, value, visited);
+}
+
+function collectOrderedSteps(
+  uwf: UwfStore,
+  headHash: CasRef,
+  chain: ChainState,
+): OrderedStepItem[] {
+  let hash: CasRef | null = headHash;
+  const hashToNode = new Map<string, { payload: StepNodePayload; timestamp: number }>();
+  while (hash !== null) {
+    const node = uwf.store.get(hash);
+    if (node === null || node.type !== uwf.schemas.stepNode) {
+      break;
+    }
+    const payload = node.payload as StepNodePayload;
+    hashToNode.set(hash, { payload, timestamp: node.timestamp });
+    hash = payload.prev;
+  }
+
+  let cur: CasRef | null = chain.headIsStart ? null : headHash;
+  const ordered: OrderedStepItem[] = [];
+  while (cur !== null) {
+    const entry = hashToNode.get(cur);
+    if (entry === undefined) {
+      break;
+    }
+    ordered.push({ hash: cur, ...entry });
+    cur = entry.payload.prev;
+  }
+
+  ordered.reverse();
+  return ordered;
+}
+
+async function resolveHeadHash(storageRoot: string, threadId: ThreadId): Promise<CasRef> {
+  const index = await loadThreadsIndex(storageRoot);
+  const head = index[threadId];
+  if (head === undefined) {
+    fail(`thread not active: ${threadId}`);
+  }
+  return head;
+}
+
+export {
+  type ChainState,
+  collectOrderedSteps,
+  expandAnyOfField,
+  expandArrayField,
+  expandCasRefField,
+  expandDeep,
+  expandObjectField,
+  expandOutput,
+  expandValue,
+  fail,
+  type OrderedStepItem,
+  resolveHeadHash,
+  walkChain,
+};
@@ -0,0 +1,145 @@
+import type {
+  CasRef,
+  StartEntry,
+  StepEntry,
+  StepNodePayload,
+  ThreadForkOutput,
+  ThreadId,
+  ThreadStepsOutput,
+} from "@uncaged/workflow-protocol";
+import { generateUlid } from "@uncaged/workflow-util";
+import { createUwfStore, loadThreadsIndex, saveThreadsIndex } from "../store.js";
+import {
+  collectOrderedSteps,
+  expandDeep,
+  expandOutput,
+  fail,
+  resolveHeadHash,
+  walkChain,
+} from "./shared.js";
+
+/**
+ * List all steps in a thread (previously: thread steps)
+ */
+export async function cmdStepList(
+  storageRoot: string,
+  threadId: ThreadId,
+): Promise<ThreadStepsOutput> {
+  const headHash = await resolveHeadHash(storageRoot, threadId);
+  const uwf = await createUwfStore(storageRoot);
+  const chain = walkChain(uwf, headHash);
+
+  const startNode = uwf.store.get(chain.startHash);
+  if (startNode === null) {
+    fail(`StartNode not found: ${chain.startHash}`);
+  }
+
+  const startEntry: StartEntry = {
+    hash: chain.startHash,
+    workflow: chain.start.workflow,
+    prompt: chain.start.prompt,
+    timestamp: startNode.timestamp,
+  };
+
+  const stepEntries: StepEntry[] = [];
+  const ordered = collectOrderedSteps(uwf, headHash, chain);
+
+  for (const item of ordered) {
+    stepEntries.push({
+      hash: item.hash,
+      role: item.payload.role,
+      output: expandOutput(uwf, item.payload.output),
+      detail: item.payload.detail ?? null,
+      agent: item.payload.agent,
+      timestamp: item.timestamp,
+    });
+  }
+
+  return {
+    thread: threadId,
+    workflow: chain.start.workflow,
+    steps: [startEntry, ...stepEntries],
+  };
+}
+
+/**
+ * Show details of a specific step (previously: thread step-details)
+ */
+export async function cmdStepShow(storageRoot: string, stepHash: CasRef): Promise<unknown> {
+  const uwf = await createUwfStore(storageRoot);
+  const node = uwf.store.get(stepHash);
+  if (node === null) {
+    fail(`CAS node not found: ${stepHash}`);
+  }
+  if (node.type !== uwf.schemas.stepNode) {
+    fail(`node ${stepHash} is not a StepNode`);
+  }
+  const payload = node.payload as StepNodePayload;
+  if (!payload.detail) {
+    fail(`step ${stepHash} has no detail`);
+  }
+  return expandDeep(uwf.store, payload.detail);
+}
+
+/**
+ * Fork a thread from a specific step (previously: thread fork)
+ */
+export async function cmdStepFork(
+  storageRoot: string,
+  stepHash: CasRef,
+): Promise<ThreadForkOutput> {
+  const uwf = await createUwfStore(storageRoot);
+  const node = uwf.store.get(stepHash);
+  if (node === null) {
+    fail(`CAS node not found: ${stepHash}`);
+  }
+  if (node.type !== uwf.schemas.startNode && node.type !== uwf.schemas.stepNode) {
+    fail(`node ${stepHash} is not a StartNode or StepNode`);
+  }
+
+  const newThreadId = generateUlid(Date.now()) as ThreadId;
+  const index = await loadThreadsIndex(storageRoot);
+  index[newThreadId] = stepHash;
+  await saveThreadsIndex(storageRoot, index);
+
+  return {
+    thread: newThreadId,
+    forkedFrom: {
+      step: stepHash,
+    },
+  };
+}
+
+/**
+ * Read a step's agent output as markdown (new command - requires #462)
+ * TODO: Implement once unified agent detail/turn schema is available
+ */
+export async function cmdStepRead(
+  storageRoot: string,
+  stepHash: CasRef,
+  _before: number | null = null,
+): Promise<string> {
+  const uwf = await createUwfStore(storageRoot);
+  const node = uwf.store.get(stepHash);
+  if (node === null) {
+    fail(`CAS node not found: ${stepHash}`);
+  }
+  if (node.type !== uwf.schemas.stepNode) {
+    fail(`node ${stepHash} is not a StepNode`);
+  }
+  const payload = node.payload as StepNodePayload;
+  if (!payload.output) {
+    fail(`step ${stepHash} has no output`);
+  }
+
+  // TODO: Implement progressive turn reading with --before N
+  // For now, return a placeholder
+  const outputNode = uwf.store.get(payload.output);
+  if (outputNode === null) {
+    fail(`output node not found: ${payload.output}`);
+  }
+
+  // Return the output as JSON for now
+  // Once #462 is implemented, this will properly format frontmatter + markdown
+  return JSON.stringify(outputNode.payload, null, 2);
+}
@@ -1,7 +1,7 @@
-import { execFileSync } from "node:child_process";
-import { readFile } from "node:fs/promises";
-import type { Store as CasStore, JSONSchema } from "@uncaged/json-cas";
-import { getSchema, validate } from "@uncaged/json-cas";
+import { execFileSync, spawn } from "node:child_process";
+import { access, readFile } from "node:fs/promises";
+import { dirname, isAbsolute, resolve as resolvePath } from "node:path";
+import { validate } from "@uncaged/json-cas";
 import { getEnvPath, loadWorkflowConfig } from "@uncaged/workflow-agent-kit";
 import { evaluate } from "@uncaged/workflow-moderator";
 import type {
@@ -9,39 +9,41 @@ import type {
  AgentConfig,
  CasRef,
  ModeratorContext,
-  StartEntry,
  StartNodePayload,
  StartOutput,
  StepContext,
-  StepEntry,
  StepNodePayload,
  StepOutput,
-  ThreadForkOutput,
  ThreadId,
  ThreadListItem,
-  ThreadStepsOutput,
  WorkflowConfig,
  WorkflowPayload,
 } from "@uncaged/workflow-protocol";
 import { createProcessLogger, generateUlid, type ProcessLogger } from "@uncaged/workflow-util";
 import { config as loadDotenv } from "dotenv";
 import { parse, stringify } from "yaml";
-
+import { createMarker, deleteMarker, isThreadRunning } from "../background/index.js";
 import {
  appendThreadHistory,
  createUwfStore,
-  discoverProjectWorkflows,
  findThreadInHistory,
  loadThreadHistory,
  loadThreadsIndex,
  loadWorkflowRegistry,
-  resolveProjectWorkflowFile,
  resolveWorkflowHash,
  saveThreadsIndex,
  type ThreadHistoryLine,
  type UwfStore,
 } from "../store.js";
 import { checkWorkflowFilenameConsistency, isCasRef, parseWorkflowPayload } from "../validate.js";
+import {
+  type ChainState,
+  collectOrderedSteps,
+  expandOutput,
+  fail,
+  type OrderedStepItem,
+  walkChain,
+} from "./shared.js";
 import { materializeWorkflowPayload } from "./workflow.js";

 const END_ROLE = "$END";
@@ -53,33 +55,88 @@ const PL_AGENT_SPAWN = "R5J2W8N4";
 const PL_AGENT_DONE = "C6P9E3H7";
 const PL_THREAD_ARCHIVED = "F4D8Q2K5";
 const PL_STEP_ERROR = "B8T5N1V6";
+const PL_BACKGROUND_START = "X7Q4W9M2";

 function failStep(plog: ProcessLogger, message: string): never {
  plog.log(PL_STEP_ERROR, message, null);
  fail(message);
 }

-type ChainState = {
-  startHash: CasRef;
-  start: StartNodePayload;
-  stepsNewestFirst: StepNodePayload[];
-  headIsStart: boolean;
-};
+/**
+ * Check if a string looks like a file path (contains path separators or has .yaml/.yml extension).
+ */
+function isFilePath(input: string): boolean {
+  return (
+    input.includes("/") || input.includes("\\") || input.endsWith(".yaml") || input.endsWith(".yml")
+  );
+}

-type OrderedStepItem = {
-  hash: CasRef;
-  payload: StepNodePayload;
-  timestamp: number;
-};
+/**
+ * Check if a workflow file exists at the given path.
+ */
+async function workflowFileExists(dir: string, name: string, ext: string): Promise<string | null> {
+  const candidate = resolvePath(dir, `${name}${ext}`);
+  try {
+    await access(candidate);
+    return candidate;
+  } catch {
+    return null;
+  }
+}

-export type KillOutput = {
-  thread: ThreadId;
-  archived: boolean;
-};
+/**
+ * Search for a workflow file in a given directory (checks both .workflow/ and .workflows/).
+ */
+async function findWorkflowInDir(dir: string, name: string): Promise<string | null> {
+  // Check .workflow/ directory first (preferred)
+  for (const ext of [".yaml", ".yml"]) {
+    const result = await workflowFileExists(resolvePath(dir, ".workflow"), name, ext);
+    if (result !== null) {
+      return result;
+    }
+  }

-function fail(message: string): never {
-  process.stderr.write(`${message}\n`);
-  process.exit(1);
+  // Check .workflows/ directory as fallback (legacy)
+  for (const ext of [".yaml", ".yml"]) {
+    const result = await workflowFileExists(resolvePath(dir, ".workflows"), name, ext);
+    if (result !== null) {
+      return result;
+    }
+  }
+
+  return null;
+}
+
+/**
+ * Traverse parent directories looking for `.workflow/<name>.yaml` or `.workflow/<name>.yml`.
+ * Returns the absolute path if found, otherwise null.
+ * Stops at filesystem root or .git directory.
+ */
+async function findWorkflowInParents(startDir: string, name: string): Promise<string | null> {
+  let currentDir = resolvePath(startDir);
+  const root = resolvePath("/");
+
+  while (true) {
+    const found = await findWorkflowInDir(currentDir, name);
+    if (found !== null) {
+      return found;
+    }
+
+    // Stop at filesystem root
+    if (currentDir === root) {
+      break;
+    }
+
+    // Move to parent directory
+    const parentDir = dirname(currentDir);
+    if (parentDir === currentDir) {
+      // Reached filesystem root
+      break;
+    }
+    currentDir = parentDir;
+  }
+
+  return null;
 }

 async function materializeLocalWorkflow(uwf: UwfStore, filePath: string): Promise<CasRef> {
@@ -123,18 +180,41 @@ async function resolveWorkflowCasRef(
  workflowId: string,
  projectRoot: string,
 ): Promise<CasRef> {
-  // Project-local resolution: check .workflows/<workflowId>.yaml first
-  const localEntries = await discoverProjectWorkflows(projectRoot);
-  const localFile = resolveProjectWorkflowFile(localEntries, workflowId);
-  if (localFile !== null) {
-    return materializeLocalWorkflow(uwf, localFile);
+  // Validate input
+  const trimmed = workflowId.trim();
+  if (trimmed === "") {
+    fail("workflow ID cannot be empty");
  }

-  // Global registry fallback
+  // Strategy 1: Direct CAS hash
+  if (isCasRef(trimmed)) {
+    const node = uwf.store.get(trimmed);
+    if (node === null) {
+      fail(`CAS node not found: ${trimmed}`);
+    }
+    if (node.type !== uwf.schemas.workflow) {
+      fail(`node ${trimmed} is not a Workflow (type ${node.type})`);
+    }
+    return trimmed;
+  }
+
+  // Strategy 2: Explicit file path (relative or absolute)
+  if (isFilePath(trimmed)) {
+    const absolutePath = isAbsolute(trimmed) ? trimmed : resolvePath(projectRoot, trimmed);
+    return materializeLocalWorkflow(uwf, absolutePath);
+  }
+
+  // Strategy 3: Local discovery (parent directory traversal)
+  const localPath = await findWorkflowInParents(projectRoot, trimmed);
+  if (localPath !== null) {
+    return materializeLocalWorkflow(uwf, localPath);
+  }
+
+  // Strategy 4: Global registry fallback
  const registry = await loadWorkflowRegistry(storageRoot);
-  const hash = resolveWorkflowHash(registry, workflowId);
+  const hash = resolveWorkflowHash(registry, trimmed);
  if (!isCasRef(hash)) {
-    fail(`workflow not found: ${workflowId}`);
+    fail(`workflow not found: ${trimmed}`);
  }
  const node = uwf.store.get(hash);
  if (node === null) {
@@ -222,6 +302,7 @@ export async function cmdThreadShow(storageRoot: string, threadId: ThreadId): Pr
      thread: threadId,
      head: activeHead,
      done: false,
+      background: null,
    };
  }

@@ -232,215 +313,79 @@ export async function cmdThreadShow(storageRoot: string, threadId: ThreadId): Pr
      thread: threadId,
      head: hist.head,
      done: true,
+      background: null,
    };
  }

  fail(`thread not found: ${threadId}`);
 }

+export type ThreadStatus = "idle" | "running" | "completed";
+
+export type ThreadListItemWithStatus = ThreadListItem & {
+  status: ThreadStatus;
+};
+
 async function threadListItemFromActive(
+  storageRoot: string,
  uwf: UwfStore,
  threadId: ThreadId,
  head: CasRef,
-): Promise<ThreadListItem | null> {
+): Promise<ThreadListItemWithStatus | null> {
  const workflow = resolveWorkflowFromHead(uwf, head);
  if (workflow === null) {
    return null;
  }
-  return { thread: threadId, workflow, head };
+
+  // Check if thread is currently running in background
+  const runningMarker = await isThreadRunning(storageRoot, threadId);
+  const status: ThreadStatus = runningMarker !== null ? "running" : "idle";
+
+  return { thread: threadId, workflow, head, status };
 }

 export async function cmdThreadList(
  storageRoot: string,
-  includeAll: boolean,
-): Promise<ThreadListItem[]> {
+  statusFilter: ThreadStatus | null,
+): Promise<ThreadListItemWithStatus[]> {
  const uwf = await createUwfStore(storageRoot);
  const index = await loadThreadsIndex(storageRoot);
-  const items: ThreadListItem[] = [];
+  const items: ThreadListItemWithStatus[] = [];

+  // Add active threads
  for (const [threadId, head] of Object.entries(index)) {
-    const item = await threadListItemFromActive(uwf, threadId as ThreadId, head);
+    const item = await threadListItemFromActive(storageRoot, uwf, threadId as ThreadId, head);
    if (item !== null) {
      items.push(item);
    }
  }

-  if (!includeAll) {
-    return items;
+  // Add completed threads if requested
+  if (statusFilter === "completed" || statusFilter === null) {
+    const activeIds = new Set(items.map((i) => i.thread));
+    const history = await loadThreadHistory(storageRoot);
+    for (const entry of history) {
+      if (!activeIds.has(entry.thread)) {
+        items.push({
+          thread: entry.thread,
+          workflow: entry.workflow,
+          head: entry.head,
+          status: "completed",
+        });
+      }
+    }
  }

-  const activeIds = new Set(items.map((i) => i.thread));
-  const history = await loadThreadHistory(storageRoot);
-  for (const entry of history) {
-    if (!activeIds.has(entry.thread)) {
-      items.push({
-        thread: entry.thread,
-        workflow: entry.workflow,
-        head: entry.head,
-      });
-    }
+  // Apply status filter if provided
+  if (statusFilter !== null) {
+    return items.filter((item) => item.status === statusFilter);
  }

  return items;
 }

-function walkChain(uwf: UwfStore, headHash: CasRef): ChainState {
-  const headNode = uwf.store.get(headHash);
-  if (headNode === null) {
-    fail(`CAS node not found: ${headHash}`);
-  }
-
-  if (headNode.type === uwf.schemas.startNode) {
-    return {
-      startHash: headHash,
-      start: headNode.payload as StartNodePayload,
-      stepsNewestFirst: [],
-      headIsStart: true,
-    };
-  }
-
-  if (headNode.type !== uwf.schemas.stepNode) {
-    fail(`head ${headHash} is not a StartNode or StepNode`);
-  }
-
-  const stepsNewestFirst: StepNodePayload[] = [];
-  let hash: CasRef | null = headHash;
-
-  while (hash !== null) {
-    const node = uwf.store.get(hash);
-    if (node === null) {
-      fail(`CAS node not found while walking chain: ${hash}`);
-    }
-    if (node.type !== uwf.schemas.stepNode) {
-      break;
-    }
-    const payload = node.payload as StepNodePayload;
-    stepsNewestFirst.push(payload);
-    hash = payload.prev;
-  }
-
-  const newest = stepsNewestFirst[0];
-  if (newest === undefined) {
-    fail(`empty step chain at head ${headHash}`);
-  }
-
-  const startNode = uwf.store.get(newest.start);
-  if (startNode === null || startNode.type !== uwf.schemas.startNode) {
-    fail(`StartNode not found: ${newest.start}`);
-  }
-
-  return {
-    startHash: newest.start,
-    start: startNode.payload as StartNodePayload,
-    stepsNewestFirst,
-    headIsStart: false,
-  };
-}
-
-function expandOutput(uwf: UwfStore, outputRef: CasRef): unknown {
-  const node = uwf.store.get(outputRef);
-  if (node === null) {
-    return {};
-  }
-  return node.payload;
-}
-
-/**
- * Recursively expand all cas_ref fields in a CAS node's payload,
- * replacing hash strings with the referenced node's expanded payload.
- */
-function expandDeep(store: CasStore, hash: CasRef, visited?: Set<string>): unknown {
-  const seen = visited ?? new Set<string>();
-  if (seen.has(hash)) return hash; // cycle guard
-  seen.add(hash);
-
-  const node = store.get(hash);
-  if (node === null) return hash;
-
-  const schema = getSchema(store, node.type);
-  if (schema === null) return node.payload;
-
-  return expandValue(store, schema, node.payload, seen);
-}
-
-function expandValue(
-  store: CasStore,
-  schema: JSONSchema,
-  value: unknown,
-  visited: Set<string>,
-): unknown {
-  // If this field is a cas_ref, expand it
-  if (schema.format === "cas_ref") {
-    if (typeof value === "string") {
-      return expandDeep(store, value as CasRef, visited);
-    }
-    return value;
-  }
-
-  // anyOf (nullable refs)
-  if (Array.isArray(schema.anyOf)) {
-    for (const sub of schema.anyOf as JSONSchema[]) {
-      if (sub.format === "cas_ref" && typeof value === "string") {
-        return expandDeep(store, value as CasRef, visited);
-      }
-    }
-    return value;
-  }
-
-  // Array of cas_ref items
-  if (schema.type === "array" && schema.items && Array.isArray(value)) {
-    const itemSchema = schema.items as JSONSchema;
-    return (value as unknown[]).map((item) => expandValue(store, itemSchema, item, visited));
-  }
-
-  // Object with properties
-  if (value !== null && typeof value === "object" && !Array.isArray(value) && schema.properties) {
-    const props = schema.properties as Record<string, JSONSchema>;
-    const obj = value as Record<string, unknown>;
-    const result: Record<string, unknown> = {};
-    for (const [key, val] of Object.entries(obj)) {
-      const propSchema = props[key];
-      result[key] = propSchema ? expandValue(store, propSchema, val, visited) : val;
-    }
-    return result;
-  }
-
-  return value;
-}
-
-function collectOrderedSteps(
-  uwf: UwfStore,
-  headHash: CasRef,
-  chain: ChainState,
-): OrderedStepItem[] {
-  let hash: CasRef | null = headHash;
-  const hashToNode = new Map<string, { payload: StepNodePayload; timestamp: number }>();
-  while (hash !== null) {
-    const node = uwf.store.get(hash);
-    if (node === null || node.type !== uwf.schemas.stepNode) {
-      break;
-    }
-    const payload = node.payload as StepNodePayload;
-    hashToNode.set(hash, { payload, timestamp: node.timestamp });
-    hash = payload.prev;
-  }
-
-  let cur: CasRef | null = chain.headIsStart ? null : headHash;
-  const ordered: OrderedStepItem[] = [];
-  while (cur !== null) {
-    const entry = hashToNode.get(cur);
-    if (entry === undefined) {
-      break;
-    }
-    ordered.push({ hash: cur, ...entry });
-    cur = entry.payload.prev;
-  }
-  ordered.reverse();
-  return ordered;
-}
-
 function formatYaml(value: unknown): string {
-  return stringify(value).trimEnd();
+  return stringify(value, { aliasDuplicateObjects: false }).trimEnd();
 }

 function formatCompactStep(index: number, item: OrderedStepItem, outputYaml: string): string {
@@ -489,6 +434,85 @@ export function extractLastAssistantContent(uwf: UwfStore, detailRef: CasRef): s
  return null;
 }

+function sliceBeforeHash(
+  candidates: OrderedStepItem[],
+  before: CasRef,
+  threadId: ThreadId,
+): OrderedStepItem[] {
+  const idx = candidates.findIndex((s) => s.hash === before);
+  if (idx === -1) {
+    fail(`step ${before} not found in thread ${threadId}`);
+  }
+  return candidates.slice(0, idx);
+}
+
+function selectByQuota(
+  candidates: OrderedStepItem[],
+  uwf: UwfStore,
+  quota: number,
+): { selected: OrderedStepItem[]; skippedCount: number } {
+  const selected: OrderedStepItem[] = [];
+  let totalChars = 0;
+  for (let i = candidates.length - 1; i >= 0; i--) {
+    const item = candidates[i];
+    if (item === undefined) continue;
+    const outputYaml = formatYaml(expandOutput(uwf, item.payload.output));
+    const blockLen = formatCompactStep(i + 1, item, outputYaml).length;
+    selected.unshift(item);
+    totalChars += blockLen;
+    if (totalChars > quota) break;
+  }
+  return { selected, skippedCount: candidates.length - selected.length };
+}
+
+function formatStepHeader(stepNum: number, item: OrderedStepItem): string {
+  const ts = new Date(item.timestamp)
+    .toISOString()
+    .replace("T", " ")
+    .replace(/\.\d+Z$/, "");
+  return [
+    `## Step ${stepNum}: ${item.payload.role} \`${item.hash}\``,
+    `**Agent:** ${item.payload.agent} | **Time:** ${ts}`,
+  ].join("\n");
+}
+
+function formatStepPrompt(
+  roleDef: WorkflowPayload["roles"][string] | undefined,
+  role: string,
+  shownPromptRoles: Set<string>,
+): string {
+  if (!roleDef || shownPromptRoles.has(role)) return "";
+  shownPromptRoles.add(role);
+  return ["", "", "<prompt>", roleDef.goal, "</prompt>"].join("\n");
+}
+
+function formatStepContent(uwf: UwfStore, item: OrderedStepItem): string {
+  if (!item.payload.detail) return "";
+  const content = extractLastAssistantContent(uwf, item.payload.detail);
+  if (content === null) return "";
+  return ["", "", "<output>", content, "</output>"].join("\n");
+}
+
+function formatStartSection(options: {
+  threadId: ThreadId;
+  workflowName: string;
+  workflowHash: CasRef;
+  prompt: string;
+  before: CasRef | null;
+  showStart: boolean;
+}): string {
+  if (options.before !== null && !options.showStart) return "";
+  return [
+    `# Thread \`${options.threadId}\``,
+    "",
+    `**Workflow:** ${options.workflowName} (\`${options.workflowHash}\`)`,
+    "",
+    "## Task",
+    "",
+    options.prompt,
+  ].join("\n");
+}
+
 function formatThreadReadMarkdown(options: {
  threadId: ThreadId;
  workflowName: string;
@@ -501,50 +525,16 @@ function formatThreadReadMarkdown(options: {
  before: CasRef | null;
  showStart: boolean;
 }): string {
-  const { ordered, uwf, workflow, quota, before, showStart } = options;
+  const { ordered, uwf, workflow, quota, before } = options;

-  // Determine which steps to consider
-  let candidates = ordered;
-  if (before !== null) {
-    const idx = candidates.findIndex((s) => s.hash === before);
-    if (idx === -1) {
-      fail(`step ${before} not found in thread ${options.threadId}`);
-    }
-    candidates = candidates.slice(0, idx);
-  }
+  const candidates = before !== null ? sliceBeforeHash(ordered, before, options.threadId) : ordered;
+  const { selected, skippedCount } = selectByQuota(candidates, uwf, quota);

-  // Walk backward from newest, accumulating chars until quota exceeded
-  const selected: OrderedStepItem[] = [];
-  let totalChars = 0;
-  for (let i = candidates.length - 1; i >= 0; i--) {
-    const item = candidates[i];
-    if (item === undefined) continue;
-    const outputYaml = formatYaml(expandOutput(uwf, item.payload.output));
-    const blockLen = formatCompactStep(i + 1, item, outputYaml).length;
-    selected.unshift(item);
-    totalChars += blockLen;
-    if (totalChars > quota) break;
-  }
-
-  const skippedCount = candidates.length - selected.length;
  const parts: string[] = [];

-  // Start section
-  if (before === null || showStart) {
-    parts.push(
-      [
-        `# Thread \`${options.threadId}\``,
-        "",
-        `**Workflow:** ${options.workflowName} (\`${options.workflowHash}\`)`,
-        "",
-        "## Task",
-        "",
-        options.prompt,
-      ].join("\n"),
-    );
-  }
+  const startSection = formatStartSection(options);
+  if (startSection !== "") parts.push(startSection);

-  // Skip hint
  if (skippedCount > 0 && selected.length > 0) {
    const firstSelected = selected[0];
    if (firstSelected !== undefined) {
@@ -554,34 +544,21 @@ function formatThreadReadMarkdown(options: {
    }
  }

-  // Step blocks
  const startIndex = candidates.length - selected.length;
+  const shownPromptRoles = new Set<string>();
  for (let i = 0; i < selected.length; i++) {
    const item = selected[i];
    if (item === undefined) continue;
    const stepNum = startIndex + i + 1;
-    const outputYaml = formatYaml(expandOutput(uwf, item.payload.output));
-    const ts = new Date(item.timestamp)
-      .toISOString()
-      .replace("T", " ")
-      .replace(/\.\d+Z$/, "");
-    const stepLines = [
-      `## Step ${stepNum}: ${item.payload.role} \`${item.hash}\``,
-      `**Agent:** ${item.payload.agent} | **Time:** ${ts}`,
-    ];
    const roleDef = workflow.roles[item.payload.role];
-    if (roleDef) {
-      const prompt = roleDef.goal;
-      stepLines.push("", "### Prompt", "", prompt);
-    }
-    if (item.payload.detail) {
-      const content = extractLastAssistantContent(uwf, item.payload.detail);
-      if (content !== null) {
-        stepLines.push("", "### Content", "", content);
-      }
-    }
-    stepLines.push("", "### Output", "", "```yaml", outputYaml, "```");
-    parts.push(stepLines.join("\n"));
+    const stepBlock = [
+      formatStepHeader(stepNum, item),
+      formatStepPrompt(roleDef, item.payload.role, shownPromptRoles),
+      formatStepContent(uwf, item),
+    ]
+      .filter((s) => s !== "")
+      .join("");
+    parts.push(stepBlock);
  }

  return parts.join("\n\n---\n\n");
@@ -594,6 +571,7 @@ function buildModeratorContext(uwf: UwfStore, chain: ChainState): ModeratorConte
    output: expandOutput(uwf, step.output),
    detail: step.detail,
    agent: step.agent,
+    edgePrompt: step.edgePrompt ?? "",
  }));
  return { start: chain.start, steps };
 }
@@ -653,19 +631,18 @@ function spawnAgent(
  role: string,
  edgePrompt: string,
 ): CasRef {
-  const argv = [...agent.args, threadId, role];
-  const env = { ...process.env, UWF_EDGE_PROMPT: edgePrompt };
+  const argv = [...agent.args, "--thread", threadId, "--role", role, "--prompt", edgePrompt];
  let stdout: string;
  try {
    stdout = execFileSync(agent.command, argv, {
      encoding: "utf8",
-      env,
      stdio: ["ignore", "pipe", "pipe"],
+      maxBuffer: 50 * 1024 * 1024, // 50 MB — stream-json output can be large
    });
  } catch (e) {
-    const err = e as NodeJS.ErrnoException & { stderr?: Buffer | string };
+    const err = e as NodeJS.ErrnoException & { stderr?: Buffer | string | null };
    const stderr =
-      err.stderr === undefined
+      err.stderr == null
        ? ""
        : typeof err.stderr === "string"
          ? err.stderr
@@ -698,31 +675,65 @@ async function archiveThread(
  });
 }

-export async function cmdThreadStep(
+export async function cmdThreadExec(
  storageRoot: string,
  threadId: ThreadId,
  agentOverride: string | null,
  count: number,
+  background: boolean,
+  backgroundWorker: boolean,
 ): Promise<StepOutput[]> {
  if (count < 1 || !Number.isInteger(count)) {
    fail(`--count must be a positive integer, got: ${count}`);
  }

+  // Check if thread is already running in background (unless we ARE the background worker)
+  if (!backgroundWorker) {
+    const runningMarker = await isThreadRunning(storageRoot, threadId);
+    if (runningMarker !== null) {
+      fail(`thread already executing in background (PID: ${runningMarker.pid})`);
+    }
+  }
+
  const workflowHash = await resolveActiveThreadWorkflowHash(storageRoot, threadId);
  const plog = createProcessLogger({
    storageRoot,
    context: { thread: threadId, workflow: workflowHash },
  });

-  const results: StepOutput[] = [];
-  for (let i = 0; i < count; i++) {
-    const result = await cmdThreadStepOnce(storageRoot, threadId, agentOverride, plog);
-    results.push(result);
-    if (result.done) {
-      break;
+  if (background && !backgroundWorker) {
+    // Spawn background process
+    return cmdThreadStepBackground(storageRoot, threadId, agentOverride, count, plog, workflowHash);
+  }
+
+  // If we're the background worker, create marker before execution
+  let markerCreated = false;
+  if (backgroundWorker) {
+    await createMarker(storageRoot, {
+      thread: threadId,
+      workflow: workflowHash,
+      pid: process.pid,
+      startedAt: Date.now(),
+    });
+    markerCreated = true;
+  }
+
+  try {
+    const results: StepOutput[] = [];
+    for (let i = 0; i < count; i++) {
+      const result = await cmdThreadStepOnce(storageRoot, threadId, agentOverride, plog);
+      results.push(result);
+      if (result.done) {
+        break;
+      }
+    }
+    return results;
+  } finally {
+    // Cleanup marker if we created one
+    if (markerCreated) {
+      await deleteMarker(storageRoot, threadId);
    }
  }
-  return results;
 }

 async function resolveActiveThreadWorkflowHash(
@@ -739,6 +750,57 @@ async function resolveActiveThreadWorkflowHash(
  return chain.start.workflow;
 }

+async function cmdThreadStepBackground(
+  storageRoot: string,
+  threadId: ThreadId,
+  agentOverride: string | null,
+  count: number,
+  plog: ProcessLogger,
+  workflowHash: CasRef,
+): Promise<StepOutput[]> {
+  // Get current head to return to caller
+  const index = await loadThreadsIndex(storageRoot);
+  const headHash = index[threadId];
+  if (headHash === undefined) {
+    failStep(plog, `thread not active: ${threadId}`);
+  }
+
+  // Spawn detached background process
+  const scriptPath = process.argv[1];
+  if (scriptPath === undefined) {
+    failStep(plog, "unable to determine script path for background execution");
+  }
+
+  const args = ["thread", "exec", threadId, "--count", String(count)];
+
+  if (agentOverride !== null) {
+    args.push("--agent", agentOverride);
+  }
+
+  // Internal flag to signal the background worker to create/cleanup markers
+  args.push("--_background-worker");
+
+  plog.log(PL_BACKGROUND_START, `spawning background process count=${count}`, null);
+
+  const child = spawn(scriptPath, args, {
+    detached: true,
+    stdio: "ignore",
+  });
+
+  child.unref();
+
+  // Return immediately with current state and background flag
+  return [
+    {
+      workflow: workflowHash,
+      thread: threadId,
+      head: headHash,
+      done: false,
+      background: true,
+    },
+  ];
+}
+
 async function cmdThreadStepOnce(
  storageRoot: string,
  threadId: ThreadId,
@@ -776,6 +838,7 @@ async function cmdThreadStepOnce(
      thread: threadId,
      head: headHash,
      done: true,
+      background: null,
    };
  }

@@ -823,6 +886,7 @@ async function cmdThreadStepOnce(
    thread: threadId,
    head: newHead,
    done,
+    background: null,
  };
 }

@@ -839,47 +903,6 @@ async function resolveHeadHash(storageRoot: string, threadId: ThreadId): Promise
  fail(`thread not found: ${threadId}`);
 }

-export async function cmdThreadSteps(
-  storageRoot: string,
-  threadId: ThreadId,
-): Promise<ThreadStepsOutput> {
-  const headHash = await resolveHeadHash(storageRoot, threadId);
-  const uwf = await createUwfStore(storageRoot);
-  const chain = walkChain(uwf, headHash);
-
-  const startNode = uwf.store.get(chain.startHash);
-  if (startNode === null) {
-    fail(`StartNode not found: ${chain.startHash}`);
-  }
-
-  const startEntry: StartEntry = {
-    hash: chain.startHash,
-    workflow: chain.start.workflow,
-    prompt: chain.start.prompt,
-    timestamp: startNode.timestamp,
-  };
-
-  const stepEntries: StepEntry[] = [];
-  const ordered = collectOrderedSteps(uwf, headHash, chain);
-
-  for (const item of ordered) {
-    stepEntries.push({
-      hash: item.hash,
-      role: item.payload.role,
-      output: expandOutput(uwf, item.payload.output),
-      detail: item.payload.detail,
-      agent: item.payload.agent,
-      timestamp: item.timestamp,
-    });
-  }
-
-  return {
-    thread: threadId,
-    workflow: chain.start.workflow,
-    steps: [startEntry, ...stepEntries],
-  };
-}
-
 export async function cmdThreadRead(
  storageRoot: string,
  threadId: ThreadId,
@@ -907,58 +930,67 @@ export async function cmdThreadRead(
  });
 }

-export async function cmdThreadFork(
-  storageRoot: string,
-  stepHash: CasRef,
-): Promise<ThreadForkOutput> {
-  const uwf = await createUwfStore(storageRoot);
-  const node = uwf.store.get(stepHash);
-  if (node === null) {
-    fail(`CAS node not found: ${stepHash}`);
-  }
-  if (node.type !== uwf.schemas.startNode && node.type !== uwf.schemas.stepNode) {
-    fail(`node ${stepHash} is not a StartNode or StepNode`);
-  }
+export type StopOutput = {
+  thread: ThreadId;
+  stopped: boolean;
+};

-  const newThreadId = generateUlid(Date.now()) as ThreadId;
-  const index = await loadThreadsIndex(storageRoot);
-  index[newThreadId] = stepHash;
-  await saveThreadsIndex(storageRoot, index);
+export type CancelOutput = {
+  thread: ThreadId;
+  cancelled: boolean;
+};

-  return {
-    thread: newThreadId,
-    forkedFrom: {
-      step: stepHash,
-    },
-  };
-}
-
-export async function cmdThreadStepDetails(
-  storageRoot: string,
-  stepHash: CasRef,
-): Promise<unknown> {
-  const uwf = await createUwfStore(storageRoot);
-  const node = uwf.store.get(stepHash);
-  if (node === null) {
-    fail(`CAS node not found: ${stepHash}`);
-  }
-  if (node.type !== uwf.schemas.stepNode) {
-    fail(`node ${stepHash} is not a StepNode`);
-  }
-  const payload = node.payload as StepNodePayload;
-  if (!payload.detail) {
-    fail(`step ${stepHash} has no detail`);
-  }
-  return expandDeep(uwf.store, payload.detail);
-}
-
-export async function cmdThreadKill(storageRoot: string, threadId: ThreadId): Promise<KillOutput> {
+/**
+ * Stop background execution of a thread (but keep thread active)
+ */
+export async function cmdThreadStop(storageRoot: string, threadId: ThreadId): Promise<StopOutput> {
  const index = await loadThreadsIndex(storageRoot);
  const head = index[threadId];
  if (head === undefined) {
    fail(`thread not active: ${threadId}`);
  }

+  // Check if thread is running in background and terminate it
+  const runningMarker = await isThreadRunning(storageRoot, threadId);
+  if (runningMarker === null) {
+    process.stderr.write(`Warning: thread ${threadId} is not currently running\n`);
+    return { thread: threadId, stopped: false };
+  }
+
+  try {
+    process.kill(runningMarker.pid, "SIGTERM");
+  } catch {
+    // Process may have already exited, ignore error
+  }
+  await deleteMarker(storageRoot, threadId);
+
+  return { thread: threadId, stopped: true };
+}
+
+/**
+ * Cancel a thread (stop execution + move to history)
+ */
+export async function cmdThreadCancel(
+  storageRoot: string,
+  threadId: ThreadId,
+): Promise<CancelOutput> {
+  const index = await loadThreadsIndex(storageRoot);
+  const head = index[threadId];
+  if (head === undefined) {
+    fail(`thread not active: ${threadId}`);
+  }
+
+  // Check if thread is running in background and terminate it
+  const runningMarker = await isThreadRunning(storageRoot, threadId);
+  if (runningMarker !== null) {
+    try {
+      process.kill(runningMarker.pid, "SIGTERM");
+    } catch {
+      // Process may have already exited, ignore error
+    }
+    await deleteMarker(storageRoot, threadId);
+  }
+
  const uwf = await createUwfStore(storageRoot);
  const workflow = resolveWorkflowFromHead(uwf, head);
  if (workflow === null) {
@@ -976,5 +1008,5 @@ export async function cmdThreadKill(storageRoot: string, threadId: ThreadId): Pr
  };
  await appendThreadHistory(storageRoot, historyEntry);

-  return { thread: threadId, archived: true };
+  return { thread: threadId, cancelled: true };
 }
@@ -29,7 +29,7 @@ export type WorkflowListEntry = {
  origin: WorkflowOrigin;
 };

-export type WorkflowPutOutput = {
+export type WorkflowAddOutput = {
  name: string;
  hash: CasRef;
 };
@@ -111,10 +111,10 @@ export async function materializeWorkflowPayload(
  };
 }

-export async function cmdWorkflowPut(
+export async function cmdWorkflowAdd(
  storageRoot: string,
  filePath: string,
-): Promise<WorkflowPutOutput> {
+): Promise<WorkflowAddOutput> {
  let text: string;
  try {
    text = await readFile(filePath, "utf8");
@@ -7,6 +7,6 @@ export function formatOutput(data: unknown, format: OutputFormat): string {
    case "json":
      return JSON.stringify(data);
    case "yaml":
-      return stringify(data).trimEnd();
+      return stringify(data, { aliasDuplicateObjects: false }).trimEnd();
  }
 }
@@ -0,0 +1,141 @@
+# @uncaged/workflow-agent-builtin
+
+`uwf-builtin` agent — built-in LLM agent with file read/write and shell tools.
+
+## Overview
+
+Layer 3 agent implementation. Runs an OpenAI-compatible chat completion loop with built-in tools (`read_file`, `write_file`, `run_command`). Uses the configured provider/model from `config.yaml`. Produces frontmatter markdown output and stores turn-by-turn session detail in CAS.
+
+Useful when you want a self-contained agent without an external CLI like Hermes or Claude Code.
+
+**Dependencies:** `@uncaged/json-cas`, `@uncaged/workflow-agent-kit`, `@uncaged/workflow-util`
+
+## Installation
+
+Included as the `uwf-builtin` binary when you install `@uncaged/workflow-agent-builtin`:
+
+```bash
+bun add -g @uncaged/workflow-agent-builtin
+```
+
+## CLI Usage
+
+Invoked by `uwf thread step`:
+
+```bash
+uwf-builtin <thread-id> <role>
+```
+
+Configure as default agent:
+
+```bash
+uwf setup --agent builtin
+```
+
+Override per step:
+
+```bash
+uwf thread step <thread-id> --agent uwf-builtin
+```
+
+Environment variables set by the engine:
+
+| Variable | Purpose |
+|----------|---------|
+| `UWF_EDGE_PROMPT` | Moderator edge instruction for this step |
+
+## API
+
+All exports come from `src/index.ts`.
+
+### Agent factory
+
+```typescript
+function createBuiltinAgent(): () => Promise<void>
+function buildBuiltinMessages(ctx: AgentContext): ChatMessage[]
+```
+
+### LLM loop
+
+```typescript
+const BUILTIN_MAX_TURNS = 30;
+const BUILTIN_CONTINUE_MAX_TURNS = 5;
+
+function runBuiltinLoop(/* options: RunBuiltinLoopOptions */): Promise<RunBuiltinLoopResult>
+function chatCompletionWithTools(
+  provider: ResolvedLlmProvider,
+  messages: ChatMessage[],
+  tools: OpenAiToolDefinition[],
+): Promise<LlmAssistantResponse>
+```
+
+`RunBuiltinLoopOptions` and `RunBuiltinLoopResult` are internal to `loop.ts` and not re-exported from `index.ts`.
+
+### Tools
+
+```typescript
+function getBuiltinTools(): readonly BuiltinTool[]
+function executeBuiltinTool(
+  name: string,
+  args: Record<string, unknown>,
+  ctx: ToolContext,
+): Promise<string>
+```
+
+### Session and detail
+
+```typescript
+function initSessionDir(storageRoot: string): Promise<void>
+function appendSessionTurn(storageRoot: string, sessionId: string, turn: BuiltinTurnPayload): Promise<void>
+function readSessionTurns(storageRoot: string, sessionId: string): Promise<BuiltinTurnPayload[]>
+function removeSession(storageRoot: string, sessionId: string): Promise<void>
+function registerBuiltinSchemas(store: Store): Promise<BuiltinSchemaHashes>
+function storeBuiltinDetail(store: Store, payload: BuiltinDetailPayload): Promise<string>
+```
+
+### Types
+
+```typescript
+type ChatMessage = /* system | user | assistant | tool */;
+type LlmAssistantResponse = { content: string | null; toolCalls: LlmToolCall[] | null };
+type LlmToolCall = { id: string; name: string; arguments: string };
+type BuiltinTool = { name: string; description: string; parameters: Record<string, unknown> };
+type ToolContext = { cwd: string; storageRoot: string };
+type BuiltinDetailPayload = { /* session turns, model, timestamps */ };
+type BuiltinLoopTurn = { /* single loop iteration record */ };
+type BuiltinToolCallRecord = { /* tool call audit */ };
+type BuiltinToolResultRecord = { /* tool result audit */ };
+type BuiltinTurnPayload = { /* persisted turn */ };
+```
+
+## Internal Structure
+
+```
+src/
+├── index.ts
+├── cli.ts              Binary entrypoint
+├── agent.ts            createBuiltinAgent
+├── loop.ts             Multi-turn LLM + tool loop
+├── prompt.ts           buildBuiltinMessages
+├── session.ts          Session directory persistence
+├── detail.ts           CAS detail node storage
+├── schemas.ts          Builtin CAS schemas
+├── types.ts            Detail and turn payload types
+├── llm/
+│   ├── index.ts
+│   ├── llm.ts          chatCompletionWithTools
+│   └── types.ts        ChatMessage, LlmToolCall, etc.
+└── tools/
+    ├── index.ts        getBuiltinTools, executeBuiltinTool
+    ├── read-file.ts
+    ├── write-file.ts
+    ├── run-command.ts
+    ├── path.ts
+    └── types.ts
+```
+
+## Configuration
+
+Requires a configured OpenAI-compatible provider and model in `~/.uncaged/workflow/config.yaml` (via `uwf setup`). API keys are loaded from `~/.uncaged/workflow/.env`.
+
+Tools run with the current working directory as `ToolContext.cwd` (typically the directory where `uwf thread step` was invoked).
@@ -0,0 +1,16 @@
+import { describe, expect, test } from "bun:test";
+
+import type { LlmToolCall } from "../src/llm/types.js";
+
+/** Mirror OpenAI response shape for parser coverage via chatCompletionWithTools integration later. */
+describe("LlmToolCall shape", () => {
+  test("tool call record fields", () => {
+    const call: LlmToolCall = {
+      id: "call_1",
+      name: "read_file",
+      arguments: '{"path":"README.md"}',
+    };
+    expect(call.name).toBe("read_file");
+    expect(JSON.parse(call.arguments)).toEqual({ path: "README.md" });
+  });
+});
@@ -0,0 +1,256 @@
+import { beforeEach, describe, expect, mock, test } from "bun:test";
+
+const mockChatCompletionWithTools = mock(async () => ({
+  content: "---\nstatus: done\n---",
+  toolCalls: [],
+}));
+const mockAppendSessionTurn = mock(async () => {});
+const mockExecuteBuiltinTool = mock(async () => "tool-result");
+
+mock.module("../src/llm/index.js", () => ({
+  chatCompletionWithTools: mockChatCompletionWithTools,
+}));
+mock.module("../src/session.js", () => ({
+  appendSessionTurn: mockAppendSessionTurn,
+}));
+mock.module("../src/tools/index.js", () => ({
+  builtinToolsToOpenAi: () => [],
+  executeBuiltinTool: mockExecuteBuiltinTool,
+  getBuiltinTools: () => [],
+}));
+
+import {
+  executeTurnTools,
+  extractFinalText,
+  runBuiltinLoop,
+  shouldInjectDeadlineWarning,
+  shouldNudge,
+  shouldProcessToolCalls,
+} from "../src/loop.js";
+
+const fakeProvider = {} as any;
+const fakeToolCtx = {} as any;
+
+function makeOptions(overrides: Partial<Parameters<typeof runBuiltinLoop>[0]> = {}) {
+  return {
+    provider: fakeProvider,
+    messages: [{ role: "system" as const, content: "sys" }],
+    toolCtx: fakeToolCtx,
+    maxTurns: 5,
+    storageRoot: "/tmp",
+    sessionId: "sess",
+    noTools: false,
+    ...overrides,
+  };
+}
+
+beforeEach(() => {
+  mockChatCompletionWithTools.mockReset();
+  mockAppendSessionTurn.mockReset();
+  mockExecuteBuiltinTool.mockReset();
+});
+
+describe("shouldNudge", () => {
+  test("2.1 returns true when all conditions met", () => {
+    expect(shouldNudge({ noTools: false, text: "some text", turn: 0, maxTurns: 5 })).toBe(true);
+  });
+  test("2.2 returns false when noTools=true", () => {
+    expect(shouldNudge({ noTools: true, text: "some text", turn: 0, maxTurns: 5 })).toBe(false);
+  });
+  test("2.3 returns false when text starts with ---", () => {
+    expect(shouldNudge({ noTools: false, text: "---\nstatus: done", turn: 0, maxTurns: 5 })).toBe(
+      false,
+    );
+  });
+  test("2.4 returns false on last turn", () => {
+    expect(shouldNudge({ noTools: false, text: "some text", turn: 4, maxTurns: 5 })).toBe(false);
+  });
+  test("2.5 returns true on second-to-last turn", () => {
+    expect(shouldNudge({ noTools: false, text: "some text", turn: 3, maxTurns: 5 })).toBe(true);
+  });
+  test("2.6 leading whitespace before --- suppresses nudge", () => {
+    expect(shouldNudge({ noTools: false, text: "  ---\nstatus: done", turn: 0, maxTurns: 5 })).toBe(
+      false,
+    );
+  });
+});
+
+describe("executeTurnTools", () => {
+  test("4.1 executes each tool call and pushes tool result messages", async () => {
+    mockExecuteBuiltinTool.mockResolvedValue("result");
+    const messages: any[] = [];
+    const calls = [
+      { id: "c1", name: "tool_a", arguments: "{}" },
+      { id: "c2", name: "tool_b", arguments: "{}" },
+    ];
+    const count = await executeTurnTools(calls, fakeToolCtx, messages, "/tmp", "sess");
+    expect(messages.length).toBe(2);
+    expect(messages[0].role).toBe("tool");
+    expect(messages[1].role).toBe("tool");
+    expect(count).toBe(2);
+  });
+  test("4.2 tool result content matches executeBuiltinTool return value", async () => {
+    mockExecuteBuiltinTool.mockResolvedValue("result-A");
+    const messages: any[] = [];
+    await executeTurnTools(
+      [{ id: "c1", name: "read_file", arguments: "{}" }],
+      fakeToolCtx,
+      messages,
+      "/tmp",
+      "sess",
+    );
+    expect(messages[0].content).toBe("result-A");
+  });
+});
+
+describe("runBuiltinLoop integration", () => {
+  test("3.1 single text-only response returns finalText immediately", async () => {
+    mockChatCompletionWithTools.mockResolvedValue({
+      content: "---\nstatus: done\n---",
+      toolCalls: [],
+    });
+    const result = await runBuiltinLoop(makeOptions());
+    expect(result.finalText).toBe("---\nstatus: done\n---");
+    expect(result.turnCount).toBe(1);
+  });
+  test("3.2 noTools=true suppresses tool calls", async () => {
+    mockChatCompletionWithTools.mockResolvedValue({
+      content: "ok",
+      toolCalls: [{ id: "c1", name: "read_file", arguments: "{}" }],
+    });
+    const result = await runBuiltinLoop(makeOptions({ noTools: true }));
+    expect(result.finalText).toBe("ok");
+    expect(result.turnCount).toBe(1);
+  });
+  test("3.3 tool call followed by text response", async () => {
+    mockChatCompletionWithTools
+      .mockResolvedValueOnce({
+        content: null,
+        toolCalls: [{ id: "c1", name: "read_file", arguments: "{}" }],
+      })
+      .mockResolvedValueOnce({ content: "---\nstatus: done\n---", toolCalls: [] });
+    mockExecuteBuiltinTool.mockResolvedValue("file contents");
+    const result = await runBuiltinLoop(makeOptions());
+    expect(result.finalText).toBe("---\nstatus: done\n---");
+    expect(result.turnCount).toBe(3);
+  });
+  test("3.4 nudge cycle inserts nudge message", async () => {
+    mockChatCompletionWithTools
+      .mockResolvedValueOnce({ content: "I am thinking", toolCalls: [] })
+      .mockResolvedValueOnce({ content: "---\nstatus: done\n---", toolCalls: [] });
+    const result = await runBuiltinLoop(makeOptions());
+    expect(result.finalText).toBe("---\nstatus: done\n---");
+    const nudgeMsg = result.messages.find(
+      (m) =>
+        m.role === "user" && typeof m.content === "string" && m.content.includes("frontmatter"),
+    );
+    expect(nudgeMsg).toBeDefined();
+  });
+  test("3.5 maxTurns exhaustion falls back to last assistant content", async () => {
+    mockChatCompletionWithTools.mockResolvedValue({ content: "still thinking", toolCalls: [] });
+    const result = await runBuiltinLoop(makeOptions({ maxTurns: 3 }));
+    expect(result.finalText).toBe("still thinking");
+  });
+  test("3.6 original messages array is not mutated", async () => {
+    mockChatCompletionWithTools.mockResolvedValue({
+      content: "---\nstatus: done\n---",
+      toolCalls: [],
+    });
+    const original = [{ role: "system" as const, content: "sys" }];
+    await runBuiltinLoop(makeOptions({ messages: original }));
+    expect(original.length).toBe(1);
+  });
+});
+
+describe("shouldInjectDeadlineWarning", () => {
+  test("5.1 returns true when turn count reaches warning threshold and not yet warned", () => {
+    expect(shouldInjectDeadlineWarning(7, 10, false, false)).toBe(true);
+  });
+  test("5.2 returns false when already warned", () => {
+    expect(shouldInjectDeadlineWarning(7, 10, true, false)).toBe(false);
+  });
+  test("5.3 returns false when noTools is true", () => {
+    expect(shouldInjectDeadlineWarning(7, 10, false, true)).toBe(false);
+  });
+  test("5.4 returns false when turns remaining > DEADLINE_WARNING_TURNS", () => {
+    expect(shouldInjectDeadlineWarning(5, 10, false, false)).toBe(false);
+  });
+  test("5.5 returns true when exactly at warning threshold", () => {
+    expect(shouldInjectDeadlineWarning(7, 10, false, false)).toBe(true);
+  });
+  test("5.6 returns false when turns remaining is 0", () => {
+    expect(shouldInjectDeadlineWarning(10, 10, false, false)).toBe(false);
+  });
+});
+
+describe("shouldProcessToolCalls", () => {
+  test("6.1 returns true when toolCalls present and noTools=false", () => {
+    expect(shouldProcessToolCalls([{ id: "x", name: "read", arguments: "{}" }], false)).toBe(true);
+  });
+  test("6.2 returns false when toolCalls is null", () => {
+    expect(shouldProcessToolCalls(null, false)).toBe(false);
+  });
+  test("6.3 returns false when toolCalls is empty array", () => {
+    expect(shouldProcessToolCalls([], false)).toBe(false);
+  });
+  test("6.4 returns false when noTools=true", () => {
+    expect(shouldProcessToolCalls([{ id: "x", name: "read", arguments: "{}" }], true)).toBe(false);
+  });
+  test("6.5 returns true when multiple tool calls present", () => {
+    expect(
+      shouldProcessToolCalls(
+        [
+          { id: "x1", name: "read", arguments: "{}" },
+          { id: "x2", name: "write", arguments: "{}" },
+        ],
+        false,
+      ),
+    ).toBe(true);
+  });
+});
+
+describe("extractFinalText", () => {
+  test("7.1 returns last assistant message content", () => {
+    const messages = [
+      { role: "system" as const, content: "sys", tool_calls: null },
+      { role: "assistant" as const, content: "first", tool_calls: null },
+      { role: "assistant" as const, content: "last", tool_calls: null },
+    ];
+    expect(extractFinalText(messages)).toBe("last");
+  });
+  test("7.2 returns empty string when no assistant messages", () => {
+    expect(extractFinalText([{ role: "system" as const, content: "sys", tool_calls: null }])).toBe(
+      "",
+    );
+  });
+  test("7.3 skips assistant messages with null content", () => {
+    const messages = [
+      { role: "assistant" as const, content: "first", tool_calls: null },
+      {
+        role: "assistant" as const,
+        content: null,
+        tool_calls: [{ id: "x", name: "t", arguments: "{}" }],
+      },
+      { role: "assistant" as const, content: "second", tool_calls: null },
+    ];
+    expect(extractFinalText(messages)).toBe("second");
+  });
+  test("7.4 skips assistant messages with empty content", () => {
+    const messages = [
+      { role: "assistant" as const, content: "first", tool_calls: null },
+      { role: "assistant" as const, content: "", tool_calls: null },
+      { role: "user" as const, content: "nudge", tool_calls: null },
+    ];
+    expect(extractFinalText(messages)).toBe("first");
+  });
+  test("7.5 handles empty messages array", () => {
+    expect(extractFinalText([])).toBe("");
+  });
+  test("7.6 handles messages with only user and system roles", () => {
+    const messages = [
+      { role: "system" as const, content: "sys", tool_calls: null },
+      { role: "user" as const, content: "query", tool_calls: null },
+    ];
+    expect(extractFinalText(messages)).toBe("");
+  });
+});
@@ -0,0 +1,21 @@
+import { describe, expect, test } from "bun:test";
+import { resolve } from "node:path";
+import { resolvePath } from "../src/tools/path.js";
+
+describe("resolvePath", () => {
+  test("resolves relative paths against cwd", () => {
+    const root = "/workspace/project";
+    const resolved = resolvePath(root, "src/foo.ts");
+    expect(resolved).toBe(resolve(root, "src/foo.ts"));
+  });
+
+  test("resolves absolute paths as-is", () => {
+    const resolved = resolvePath("/workspace", "/etc/hosts");
+    expect(resolved).toBe("/etc/hosts");
+  });
+
+  test("resolves parent traversal normally", () => {
+    const resolved = resolvePath("/workspace/project", "../other/file.ts");
+    expect(resolved).toBe(resolve("/workspace/project", "../other/file.ts"));
+  });
+});
@@ -0,0 +1,236 @@
+import { describe, expect, test } from "bun:test";
+
+import type { AgentContext } from "@uncaged/workflow-agent-kit";
+
+import { buildBuiltinMessages } from "../src/prompt.js";
+
+function minimalContext(overrides: Partial<AgentContext> = {}): AgentContext {
+  return {
+    threadId: "00000000000000000000000000" as AgentContext["threadId"],
+    role: "developer",
+    store: {} as AgentContext["store"],
+    workflow: {
+      name: "test",
+      description: "test workflow",
+      roles: {
+        developer: {
+          description: "Developer role",
+          goal: "Ship the fix",
+          capabilities: ["file-edit"],
+          procedure: "Edit files",
+          output: "A patch",
+          frontmatter: "schema-hash",
+        },
+      },
+      conditions: {},
+      graph: {},
+    },
+    start: { workflow: "wf-hash", prompt: "Fix the bug" },
+    steps: [],
+    outputFormatInstruction: "---\nstatus: done\n---",
+    edgePrompt: "Implement the fix described in the plan.",
+    isFirstVisit: true,
+    ...overrides,
+  };
+}
+
+describe("buildBuiltinMessages", () => {
+  test("system includes output format and role goal", () => {
+    const messages = buildBuiltinMessages(minimalContext());
+    const system = messages[0];
+    expect(system?.role).toBe("system");
+    if (system?.role === "system") {
+      expect(system.content).toContain("status: done");
+      expect(system.content).toContain("## Goal");
+      expect(system.content).toContain("Ship the fix");
+    }
+  });
+
+  test("first visit produces system + single user message with edge prompt", () => {
+    const messages = buildBuiltinMessages(minimalContext());
+    expect(messages).toHaveLength(2);
+    expect(messages[1]?.role).toBe("user");
+    if (messages[1]?.role === "user") {
+      expect(messages[1].content).toContain("Implement the fix");
+      expect(messages[1].content).not.toContain("## What Happened Since Your Last Turn");
+    }
+  });
+
+  test("first visit with prior steps includes inter-step summary in final user message", () => {
+    const messages = buildBuiltinMessages(
+      minimalContext({
+        steps: [
+          {
+            role: "planner",
+            output: { plan: "step 1" },
+            agent: "uwf-builtin",
+            detail: "detail-hash",
+            edgePrompt: "Create a plan.",
+          },
+        ],
+      }),
+    );
+    expect(messages).toHaveLength(2);
+    const finalUser = messages[1];
+    if (finalUser?.role === "user") {
+      expect(finalUser.content).toContain("Implement the fix");
+      expect(finalUser.content).toContain("## What Happened Since Your Last Turn");
+      expect(finalUser.content).toContain("planner");
+    }
+  });
+
+  test("re-entry reconstructs prior user/assistant turns plus current user message", () => {
+    const messages = buildBuiltinMessages(
+      minimalContext({
+        isFirstVisit: false,
+        edgePrompt: "Fix the reviewer's feedback.",
+        steps: [
+          {
+            role: "developer",
+            output: { summary: "Initial fix" },
+            agent: "uwf-builtin",
+            detail: "detail-1",
+            edgePrompt: "Implement the fix.",
+          },
+          {
+            role: "reviewer",
+            output: { approved: false, comments: "Missing tests" },
+            agent: "uwf-builtin",
+            detail: "detail-2",
+            edgePrompt: "Review the implementation.",
+          },
+        ],
+      }),
+    );
+
+    expect(messages).toHaveLength(4);
+    expect(messages[0]?.role).toBe("system");
+    expect(messages[1]?.role).toBe("user");
+    expect(messages[2]?.role).toBe("assistant");
+    expect(messages[3]?.role).toBe("user");
+
+    if (messages[1]?.role === "user") {
+      expect(messages[1].content).toBe("Implement the fix.");
+    }
+    if (messages[2]?.role === "assistant") {
+      expect(messages[2].content).toBe(JSON.stringify({ summary: "Initial fix" }));
+    }
+    if (messages[3]?.role === "user") {
+      expect(messages[3].content).toContain("Fix the reviewer's feedback.");
+      expect(messages[3].content).toContain("## What Happened Since Your Last Turn");
+      expect(messages[3].content).toContain("reviewer");
+      expect(messages[3].content).toContain("Missing tests");
+    }
+  });
+
+  test("prefix is stable across re-entry for LLM cache hits", () => {
+    const firstVisitMessages = buildBuiltinMessages(
+      minimalContext({
+        edgePrompt: "Implement the fix.",
+        steps: [],
+      }),
+    );
+
+    const reEntryMessages = buildBuiltinMessages(
+      minimalContext({
+        isFirstVisit: false,
+        edgePrompt: "Fix the reviewer's feedback.",
+        steps: [
+          {
+            role: "developer",
+            output: { summary: "Initial fix" },
+            agent: "uwf-builtin",
+            detail: "detail-1",
+            edgePrompt: "Implement the fix.",
+          },
+          {
+            role: "reviewer",
+            output: { approved: false },
+            agent: "uwf-builtin",
+            detail: "detail-2",
+            edgePrompt: "Review the code.",
+          },
+        ],
+      }),
+    );
+
+    expect(reEntryMessages[0]).toEqual(firstVisitMessages[0]);
+    expect(reEntryMessages[1]).toEqual(firstVisitMessages[1]);
+    expect(reEntryMessages[2]?.role).toBe("assistant");
+    if (reEntryMessages[2]?.role === "assistant") {
+      expect(reEntryMessages[2].content).toBe(JSON.stringify({ summary: "Initial fix" }));
+    }
+    expect(reEntryMessages[3]?.role).toBe("user");
+    if (reEntryMessages[3]?.role === "user") {
+      expect(reEntryMessages[3].content).toContain("Fix the reviewer's feedback.");
+    }
+  });
+
+  test("multiple prior visits emit one user/assistant pair per visit", () => {
+    const messages = buildBuiltinMessages(
+      minimalContext({
+        isFirstVisit: false,
+        edgePrompt: "Third round fix.",
+        steps: [
+          {
+            role: "developer",
+            output: { round: 1 },
+            agent: "uwf-builtin",
+            detail: "d1",
+            edgePrompt: "First attempt.",
+          },
+          {
+            role: "reviewer",
+            output: { approved: false },
+            agent: "uwf-builtin",
+            detail: "d2",
+            edgePrompt: "Review round 1.",
+          },
+          {
+            role: "developer",
+            output: { round: 2 },
+            agent: "uwf-builtin",
+            detail: "d3",
+            edgePrompt: "Second attempt.",
+          },
+          {
+            role: "reviewer",
+            output: { approved: false },
+            agent: "uwf-builtin",
+            detail: "d4",
+            edgePrompt: "Review round 2.",
+          },
+        ],
+      }),
+    );
+
+    expect(messages).toHaveLength(6);
+    expect(messages.map((m) => m.role)).toEqual([
+      "system",
+      "user",
+      "assistant",
+      "user",
+      "assistant",
+      "user",
+    ]);
+
+    if (messages[1]?.role === "user") {
+      expect(messages[1].content).toBe("First attempt.");
+    }
+    if (messages[2]?.role === "assistant") {
+      expect(messages[2].content).toBe(JSON.stringify({ round: 1 }));
+    }
+    if (messages[3]?.role === "user") {
+      expect(messages[3].content).toContain("Second attempt.");
+      expect(messages[3].content).toContain("reviewer");
+    }
+    if (messages[4]?.role === "assistant") {
+      expect(messages[4].content).toBe(JSON.stringify({ round: 2 }));
+    }
+    if (messages[5]?.role === "user") {
+      expect(messages[5].content).toContain("Third round fix.");
+      expect(messages[5].content).toContain("### Step 4: reviewer");
+      expect(messages[5].content).toContain('"approved":false');
+    }
+  });
+});
@@ -0,0 +1,34 @@
+{
+  "name": "@uncaged/workflow-agent-builtin",
+  "version": "0.5.0",
+  "files": [
+    "src",
+    "dist",
+    "package.json"
+  ],
+  "type": "module",
+  "bin": {
+    "uwf-builtin": "./src/cli.ts"
+  },
+  "exports": {
+    ".": {
+      "bun": "./src/index.ts",
+      "types": "./dist/index.d.ts",
+      "import": "./dist/index.js"
+    }
+  },
+  "scripts": {
+    "test": "bun test"
+  },
+  "dependencies": {
+    "@uncaged/json-cas": "^0.4.0",
+    "@uncaged/workflow-agent-kit": "workspace:^",
+    "@uncaged/workflow-util": "workspace:^"
+  },
+  "devDependencies": {
+    "typescript": "^5.8.3"
+  },
+  "publishConfig": {
+    "access": "public"
+  }
+}
@@ -0,0 +1,158 @@
+import type { Store } from "@uncaged/json-cas";
+import {
+  type AgentContext,
+  type AgentRunResult,
+  createAgent,
+  loadWorkflowConfig,
+  resolveModel,
+  resolveStorageRoot,
+} from "@uncaged/workflow-agent-kit";
+import { createLogger, generateUlid } from "@uncaged/workflow-util";
+
+import { storeBuiltinDetail } from "./detail.js";
+import type { ChatMessage } from "./llm/index.js";
+import { BUILTIN_CONTINUE_MAX_TURNS, BUILTIN_MAX_TURNS, runBuiltinLoop } from "./loop.js";
+import { buildBuiltinMessages } from "./prompt.js";
+import { initSessionDir } from "./session.js";
+
+const log = createLogger({ sink: { kind: "stderr" } });
+
+const FRONTMATTER_FENCE = "---";
+
+/**
+ * Strip any text before the first `---` fence.
+ * LLMs sometimes emit preamble text before the frontmatter block.
+ */
+function stripPreamble(text: string): string {
+  if (text.startsWith(FRONTMATTER_FENCE)) {
+    return text;
+  }
+  const idx = text.indexOf(`\n${FRONTMATTER_FENCE}\n`);
+  if (idx !== -1) {
+    log("6GWRP3QX", `stripped ${idx + 1} chars of preamble before frontmatter`);
+    return text.slice(idx + 1);
+  }
+  return text;
+}
+
+type SessionRecord = {
+  sessionId: string;
+  model: string;
+  startedAtMs: number;
+  messages: ChatMessage[];
+};
+
+const sessions = new Map<string, SessionRecord>();
+
+function getSession(sessionId: string): SessionRecord {
+  const session = sessions.get(sessionId);
+  if (session === undefined) {
+    throw new Error(`builtin session not found: ${sessionId}`);
+  }
+  return session;
+}
+
+function buildToolContext(storageRoot: string): { cwd: string; storageRoot: string } {
+  return {
+    cwd: process.cwd(),
+    storageRoot,
+  };
+}
+
+async function runBuiltinWithMessages(
+  storageRoot: string,
+  provider: ReturnType<typeof resolveModel>,
+  messages: ChatMessage[],
+  session: SessionRecord,
+  store: Store,
+  maxTurns: number,
+  noTools: boolean,
+): Promise<AgentRunResult> {
+  const loopResult = await runBuiltinLoop({
+    provider,
+    messages,
+    toolCtx: buildToolContext(storageRoot),
+    maxTurns,
+    storageRoot,
+    sessionId: session.sessionId,
+    noTools,
+  });
+
+  session.messages = loopResult.messages;
+
+  if (loopResult.turnCount === 0) {
+    log("5RWTK9NB", "no turns produced, returning empty output");
+    return { output: "", detailHash: "", sessionId: session.sessionId };
+  }
+
+  // Read jsonl → persist turns to CAS → store detail
+  const { detailHash } = await storeBuiltinDetail(
+    store,
+    storageRoot,
+    session.sessionId,
+    session.model,
+    session.startedAtMs,
+  );
+
+  return { output: stripPreamble(loopResult.finalText), detailHash, sessionId: session.sessionId };
+}
+
+async function runBuiltin(ctx: AgentContext): Promise<AgentRunResult> {
+  const storageRoot = resolveStorageRoot();
+  const config = await loadWorkflowConfig(storageRoot);
+  const provider = resolveModel(config, config.defaultModel);
+
+  const sessionId = generateUlid(Date.now());
+  await initSessionDir(storageRoot);
+  const messages = buildBuiltinMessages(ctx);
+
+  const session: SessionRecord = {
+    sessionId,
+    model: provider.model,
+    startedAtMs: Date.now(),
+    messages,
+  };
+  sessions.set(sessionId, session);
+
+  return runBuiltinWithMessages(
+    storageRoot,
+    provider,
+    messages,
+    session,
+    ctx.store,
+    BUILTIN_MAX_TURNS,
+    false,
+  );
+}
+
+async function continueBuiltin(
+  sessionId: string,
+  message: string,
+  store: Store,
+): Promise<AgentRunResult> {
+  const session = getSession(sessionId);
+  const storageRoot = resolveStorageRoot();
+  const config = await loadWorkflowConfig(storageRoot);
+  const provider = resolveModel(config, config.defaultModel);
+
+  const messages: ChatMessage[] = [...session.messages, { role: "user", content: message }];
+
+  return runBuiltinWithMessages(
+    storageRoot,
+    provider,
+    messages,
+    session,
+    store,
+    BUILTIN_CONTINUE_MAX_TURNS,
+    true,
+  );
+}
+
+/** Agent CLI factory: built-in LLM loop with file/shell tools. */
+export function createBuiltinAgent(): () => Promise<void> {
+  return createAgent({
+    name: "builtin",
+    run: runBuiltin,
+    continue: continueBuiltin,
+  });
+}
@@ -0,0 +1,6 @@
+#!/usr/bin/env bun
+
+import { createBuiltinAgent } from "./agent.js";
+
+const main = createBuiltinAgent();
+void main();
@@ -0,0 +1,49 @@
+import { bootstrap, putSchema, type Store } from "@uncaged/json-cas";
+
+import { BUILTIN_DETAIL_SCHEMA, BUILTIN_TURN_SCHEMA } from "./schemas.js";
+import { readSessionTurns } from "./session.js";
+import type { BuiltinDetailPayload } from "./types.js";
+
+type BuiltinSchemaHashes = {
+  turn: string;
+  detail: string;
+};
+
+export async function registerBuiltinSchemas(store: Store): Promise<BuiltinSchemaHashes> {
+  await bootstrap(store);
+  const [turn, detail] = await Promise.all([
+    putSchema(store, BUILTIN_TURN_SCHEMA),
+    putSchema(store, BUILTIN_DETAIL_SCHEMA),
+  ]);
+  return { turn, detail };
+}
+
+/** Read session jsonl, persist each turn to CAS, return detail hash. */
+export async function storeBuiltinDetail(
+  store: Store,
+  storageRoot: string,
+  sessionId: string,
+  model: string,
+  startedAtMs: number,
+  nowMs: number = Date.now(),
+): Promise<{ detailHash: string; turnCount: number }> {
+  const schemas = await registerBuiltinSchemas(store);
+  const turns = await readSessionTurns(storageRoot, sessionId);
+
+  const turnHashes: string[] = [];
+  for (const turn of turns) {
+    const hash = await store.put(schemas.turn, turn);
+    turnHashes.push(hash);
+  }
+
+  const duration = Math.max(0, nowMs - startedAtMs);
+  const detail: BuiltinDetailPayload = {
+    sessionId,
+    model,
+    duration,
+    turnCount: turnHashes.length,
+    turns: turnHashes,
+  };
+  const detailHash = await store.put(schemas.detail, detail);
+  return { detailHash, turnCount: turnHashes.length };
+}
@@ -0,0 +1,16 @@
+export { createBuiltinAgent } from "./agent.js";
+export { registerBuiltinSchemas, storeBuiltinDetail } from "./detail.js";
+export type { ChatMessage, LlmAssistantResponse, LlmToolCall } from "./llm/index.js";
+export { chatCompletionWithTools } from "./llm/index.js";
+export { BUILTIN_CONTINUE_MAX_TURNS, BUILTIN_MAX_TURNS, runBuiltinLoop } from "./loop.js";
+export { buildBuiltinMessages } from "./prompt.js";
+export { appendSessionTurn, initSessionDir, readSessionTurns, removeSession } from "./session.js";
+export type { BuiltinTool, ToolContext } from "./tools/index.js";
+export { executeBuiltinTool, getBuiltinTools } from "./tools/index.js";
+export type {
+  BuiltinDetailPayload,
+  BuiltinLoopTurn,
+  BuiltinToolCallRecord,
+  BuiltinToolResultRecord,
+  BuiltinTurnPayload,
+} from "./types.js";
@@ -0,0 +1,7 @@
+export { chatCompletionWithTools } from "./llm.js";
+export type {
+  ChatMessage,
+  LlmAssistantResponse,
+  LlmToolCall,
+  OpenAiToolDefinition,
+} from "./types.js";
@@ -0,0 +1,139 @@
+import type { ResolvedLlmProvider } from "@uncaged/workflow-agent-kit";
+
+import type {
+  ChatMessage,
+  LlmAssistantResponse,
+  LlmToolCall,
+  OpenAiToolDefinition,
+} from "./types.js";
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+function chatUrl(baseUrl: string): string {
+  const trimmed = baseUrl.replace(/\/+$/, "");
+  return `${trimmed}/chat/completions`;
+}
+
+function parseToolCalls(raw: unknown): LlmToolCall[] | null {
+  if (!Array.isArray(raw) || raw.length === 0) {
+    return null;
+  }
+  const calls: LlmToolCall[] = [];
+  for (const entry of raw) {
+    if (!isRecord(entry)) {
+      continue;
+    }
+    const id = entry.id;
+    const fn = entry.function;
+    if (typeof id !== "string" || !isRecord(fn)) {
+      continue;
+    }
+    const name = fn.name;
+    const args = fn.arguments;
+    if (typeof name !== "string" || typeof args !== "string") {
+      continue;
+    }
+    calls.push({ id, name, arguments: args });
+  }
+  return calls.length > 0 ? calls : null;
+}
+
+function parseAssistantMessage(parsed: unknown): LlmAssistantResponse {
+  if (!isRecord(parsed)) {
+    throw new Error("LLM response is not an object");
+  }
+  const choices = parsed.choices;
+  if (!Array.isArray(choices) || choices.length === 0) {
+    throw new Error("LLM response has no choices");
+  }
+  const c0 = choices[0];
+  if (!isRecord(c0)) {
+    throw new Error("LLM choice is not an object");
+  }
+  const messageObj = c0.message;
+  if (!isRecord(messageObj)) {
+    throw new Error("LLM message is not an object");
+  }
+  const contentRaw = messageObj.content;
+  const content =
+    typeof contentRaw === "string"
+      ? contentRaw
+      : contentRaw === null || contentRaw === undefined
+        ? null
+        : null;
+  const toolCalls = parseToolCalls(messageObj.tool_calls);
+  return { content, toolCalls };
+}
+
+function serializeMessage(message: ChatMessage): Record<string, unknown> {
+  if (message.role === "tool") {
+    return {
+      role: "tool",
+      tool_call_id: message.tool_call_id,
+      content: message.content,
+    };
+  }
+  if (message.role === "assistant") {
+    const base: Record<string, unknown> = {
+      role: "assistant",
+      content: message.content,
+    };
+    if (message.tool_calls !== null && message.tool_calls.length > 0) {
+      base.tool_calls = message.tool_calls.map((call) => ({
+        id: call.id,
+        type: "function",
+        function: { name: call.name, arguments: call.arguments },
+      }));
+    }
+    return base;
+  }
+  return { role: message.role, content: message.content };
+}
+
+/** OpenAI-compatible chat completion with tool calling (non-streaming). */
+export async function chatCompletionWithTools(
+  provider: ResolvedLlmProvider,
+  messages: ChatMessage[],
+  tools: OpenAiToolDefinition[] | null,
+): Promise<LlmAssistantResponse> {
+  const body: Record<string, unknown> = {
+    model: provider.model,
+    messages: messages.map(serializeMessage),
+  };
+  if (tools !== null && tools.length > 0) {
+    body.tools = tools;
+    body.tool_choice = "auto";
+  }
+
+  let response: Response;
+  try {
+    response = await fetch(chatUrl(provider.baseUrl), {
+      method: "POST",
+      headers: {
+        Authorization: `Bearer ${provider.apiKey}`,
+        "Content-Type": "application/json",
+      },
+      body: JSON.stringify(body),
+    });
+  } catch (cause) {
+    const message = cause instanceof Error ? cause.message : String(cause);
+    throw new Error(`LLM network error: ${message}`);
+  }
+
+  const responseText = await response.text();
+  if (!response.ok) {
+    throw new Error(`LLM HTTP ${response.status}: ${responseText.slice(0, 2000)}`);
+  }
+
+  let parsed: unknown;
+  try {
+    parsed = JSON.parse(responseText) as unknown;
+  } catch (cause) {
+    const message = cause instanceof Error ? cause.message : String(cause);
+    throw new Error(`LLM invalid JSON response: ${message}`);
+  }
+
+  return parseAssistantMessage(parsed);
+}
@@ -0,0 +1,29 @@
+export type LlmToolCall = {
+  id: string;
+  name: string;
+  arguments: string;
+};
+
+export type LlmAssistantResponse = {
+  content: string | null;
+  toolCalls: LlmToolCall[] | null;
+};
+
+export type ChatMessage =
+  | { role: "system"; content: string }
+  | { role: "user"; content: string }
+  | {
+      role: "assistant";
+      content: string | null;
+      tool_calls: LlmToolCall[] | null;
+    }
+  | { role: "tool"; tool_call_id: string; content: string };
+
+export type OpenAiToolDefinition = {
+  type: "function";
+  function: {
+    name: string;
+    description: string;
+    parameters: Record<string, unknown>;
+  };
+};
@@ -0,0 +1,303 @@
+import type { ResolvedLlmProvider } from "@uncaged/workflow-agent-kit";
+import { createLogger } from "@uncaged/workflow-util";
+
+import {
+  type ChatMessage,
+  chatCompletionWithTools,
+  type LlmToolCall,
+  type OpenAiToolDefinition,
+} from "./llm/index.js";
+import { appendSessionTurn } from "./session.js";
+import {
+  builtinToolsToOpenAi,
+  executeBuiltinTool,
+  getBuiltinTools,
+  type ToolContext,
+} from "./tools/index.js";
+import type { BuiltinToolCall, BuiltinTurnPayload } from "./types.js";
+
+const log = createLogger({ sink: { kind: "stderr" } });
+
+export const BUILTIN_MAX_TURNS = 30;
+export const BUILTIN_CONTINUE_MAX_TURNS = 5;
+
+export type RunBuiltinLoopOptions = {
+  provider: ResolvedLlmProvider;
+  messages: ChatMessage[];
+  toolCtx: ToolContext;
+  maxTurns: number;
+  storageRoot: string;
+  sessionId: string;
+  /** When true, do not provide tools — force LLM to emit text only. */
+  noTools: boolean;
+};
+
+export type RunBuiltinLoopResult = {
+  finalText: string;
+  messages: ChatMessage[];
+  turnCount: number;
+};
+
+function mapToolCallsForPayload(calls: LlmToolCall[]): BuiltinToolCall[] {
+  return calls.map((call) => ({
+    name: call.name,
+    args: call.arguments,
+  }));
+}
+
+async function appendTurn(
+  storageRoot: string,
+  sessionId: string,
+  payload: BuiltinTurnPayload,
+): Promise<void> {
+  await appendSessionTurn(storageRoot, sessionId, payload);
+}
+
+export async function executeTurnTools(
+  calls: Array<{ id: string; name: string; arguments: string }>,
+  toolCtx: ToolContext,
+  messages: ChatMessage[],
+  storageRoot: string,
+  sessionId: string,
+): Promise<number> {
+  let turnCount = 0;
+  for (const call of calls) {
+    const result = await executeBuiltinTool(call.name, call.arguments, toolCtx);
+    messages.push({ role: "tool", tool_call_id: call.id, content: result });
+    await appendTurn(storageRoot, sessionId, {
+      role: "tool",
+      content: result,
+      toolCalls: null,
+      reasoning: null,
+    });
+    turnCount += 1;
+  }
+  return turnCount;
+}
+
+export type ShouldNudgeOptions = {
+  noTools: boolean;
+  text: string;
+  turn: number;
+  maxTurns: number;
+};
+
+const MAX_NUDGES = 3;
+const DEADLINE_WARNING_TURNS = 3;
+
+export function shouldInjectDeadlineWarning(
+  turn: number,
+  maxTurns: number,
+  alreadyWarned: boolean,
+  noTools: boolean,
+): boolean {
+  const turnsRemaining = maxTurns - turn;
+  return (
+    !noTools && !alreadyWarned && turnsRemaining > 0 && turnsRemaining <= DEADLINE_WARNING_TURNS
+  );
+}
+
+export function shouldProcessToolCalls(toolCalls: LlmToolCall[] | null, noTools: boolean): boolean {
+  return !noTools && toolCalls !== null && toolCalls.length > 0;
+}
+
+export function extractFinalText(messages: ChatMessage[]): string {
+  for (let i = messages.length - 1; i >= 0; i--) {
+    const msg = messages[i];
+    if (
+      msg !== undefined &&
+      msg.role === "assistant" &&
+      msg.content !== null &&
+      msg.content.trim() !== ""
+    ) {
+      return msg.content;
+    }
+  }
+  return "";
+}
+
+function injectDeadlineWarning(messages: ChatMessage[], turnsRemaining: number): void {
+  log("4NRXW6KT", `${turnsRemaining} turns remaining, injecting deadline warning`);
+  messages.push({
+    role: "user",
+    content:
+      `⚠️ You have ${turnsRemaining} turns remaining. ` +
+      "Wrap up your work and output the YAML frontmatter starting with `---`. " +
+      "If you cannot finish in time, output frontmatter with `status: failed` and describe what remains.",
+  });
+}
+
+type HandleTextOnlyTurnResult = {
+  shouldBreak: boolean;
+  finalText: string;
+  turnCount: number;
+  nudgeCount: number;
+  turnAdjustment: number;
+};
+
+async function handleTextOnlyTurn(
+  text: string,
+  messages: ChatMessage[],
+  storageRoot: string,
+  sessionId: string,
+  noTools: boolean,
+  turn: number,
+  maxTurns: number,
+  currentNudgeCount: number,
+): Promise<HandleTextOnlyTurnResult> {
+  await appendTurn(storageRoot, sessionId, {
+    role: "assistant",
+    content: text,
+    toolCalls: null,
+    reasoning: null,
+  });
+  const turnCount = 1;
+  let nudgeCount = currentNudgeCount;
+  let turnAdjustment = 0;
+
+  if (shouldNudge({ noTools, text, turn, maxTurns })) {
+    nudgeCount += 1;
+    log("7FXQM2KN", `text-only turn without frontmatter, nudge ${nudgeCount}/${MAX_NUDGES}`);
+    const nudge =
+      "You stopped calling tools but your response does not start with the required `---` YAML frontmatter. " +
+      "Either continue using tools to complete your work, or output your final response starting with `---`.";
+    messages.push({ role: "user", content: nudge });
+    // Nudge doesn't consume turn budget (up to MAX_NUDGES)
+    if (nudgeCount <= MAX_NUDGES) {
+      turnAdjustment = -1;
+    }
+    return { shouldBreak: false, finalText: "", turnCount, nudgeCount, turnAdjustment };
+  }
+
+  return { shouldBreak: true, finalText: text, turnCount, nudgeCount, turnAdjustment };
+}
+
+async function handleToolCallTurn(
+  content: string,
+  toolCalls: LlmToolCall[],
+  messages: ChatMessage[],
+  storageRoot: string,
+  sessionId: string,
+  toolCtx: ToolContext,
+): Promise<number> {
+  await appendTurn(storageRoot, sessionId, {
+    role: "assistant",
+    content,
+    toolCalls: mapToolCallsForPayload(toolCalls),
+    reasoning: null,
+  });
+  let turnCount = 1;
+
+  // Execute tools
+  turnCount += await executeTurnTools(toolCalls, toolCtx, messages, storageRoot, sessionId);
+
+  return turnCount;
+}
+
+export function shouldNudge({ noTools, text, turn, maxTurns }: ShouldNudgeOptions): boolean {
+  return !noTools && !text.trimStart().startsWith("---") && turn < maxTurns - 1;
+}
+
+type ProcessLoopIterationResult = {
+  shouldBreak: boolean;
+  finalText: string;
+  turnCount: number;
+  nudgeCount: number;
+  turnAdjustment: number;
+};
+
+async function processLoopIteration(
+  options: RunBuiltinLoopOptions,
+  messages: ChatMessage[],
+  openAiTools: OpenAiToolDefinition[],
+  turn: number,
+  nudgeCount: number,
+): Promise<ProcessLoopIterationResult> {
+  const response = await chatCompletionWithTools(
+    options.provider,
+    messages,
+    openAiTools.length > 0 ? openAiTools : null,
+  );
+
+  // When noTools is set, ignore any tool_calls the LLM might still return
+  const effectiveToolCalls = options.noTools ? null : (response.toolCalls ?? null);
+
+  const assistantMessage: ChatMessage = {
+    role: "assistant",
+    content: response.content,
+    tool_calls: effectiveToolCalls,
+  };
+  messages.push(assistantMessage);
+
+  if (!shouldProcessToolCalls(effectiveToolCalls, options.noTools)) {
+    const text = response.content ?? "";
+    const result = await handleTextOnlyTurn(
+      text,
+      messages,
+      options.storageRoot,
+      options.sessionId,
+      options.noTools,
+      turn,
+      options.maxTurns,
+      nudgeCount,
+    );
+    return result;
+  }
+
+  // At this point, effectiveToolCalls is guaranteed to be non-null and non-empty
+  const turnCount = await handleToolCallTurn(
+    response.content ?? "",
+    effectiveToolCalls as LlmToolCall[],
+    messages,
+    options.storageRoot,
+    options.sessionId,
+    options.toolCtx,
+  );
+
+  return {
+    shouldBreak: false,
+    finalText: "",
+    turnCount,
+    nudgeCount,
+    turnAdjustment: 0,
+  };
+}
+
+/** Agent run loop: LLM ↔ tools until no tool_calls or maxTurns. */
+export async function runBuiltinLoop(
+  options: RunBuiltinLoopOptions,
+): Promise<RunBuiltinLoopResult> {
+  const messages = [...options.messages];
+  const openAiTools = options.noTools ? [] : builtinToolsToOpenAi(getBuiltinTools());
+  let finalText = "";
+  let turnCount = 0;
+  let nudgeCount = 0;
+  let deadlineWarned = false;
+
+  for (let turn = 0; turn < options.maxTurns; turn++) {
+    log("8K2M4N7P", `builtin loop turn ${turn + 1}/${options.maxTurns}`);
+
+    // Warn agent when approaching turn limit
+    if (shouldInjectDeadlineWarning(turn, options.maxTurns, deadlineWarned, options.noTools)) {
+      deadlineWarned = true;
+      const turnsRemaining = options.maxTurns - turn;
+      injectDeadlineWarning(messages, turnsRemaining);
+    }
+
+    const result = await processLoopIteration(options, messages, openAiTools, turn, nudgeCount);
+    turnCount += result.turnCount;
+    nudgeCount = result.nudgeCount;
+    turn += result.turnAdjustment;
+
+    if (result.shouldBreak) {
+      finalText = result.finalText;
+      break;
+    }
+  }
+
+  if (finalText === "") {
+    finalText = extractFinalText(messages);
+  }
+
+  return { finalText, messages, turnCount };
+}
@@ -0,0 +1,115 @@
+import { type AgentContext, buildRolePrompt } from "@uncaged/workflow-agent-kit";
+
+import type { ChatMessage } from "./llm/index.js";
+
+type StepContext = AgentContext["steps"][number];
+
+function formatStep(step: StepContext, stepNumber: number): string {
+  return [
+    `### Step ${stepNumber}: ${step.role}`,
+    `Output: ${JSON.stringify(step.output)}`,
+    `Agent: ${step.agent}`,
+  ].join("\n");
+}
+
+function buildStepsSummary(steps: StepContext[], fromIndex: number, toIndex: number): string {
+  if (fromIndex >= toIndex) {
+    return "";
+  }
+
+  const lines: string[] = ["## What Happened Since Your Last Turn"];
+  for (let i = fromIndex; i < toIndex; i++) {
+    const step = steps[i];
+    if (step === undefined) {
+      continue;
+    }
+    lines.push("");
+    lines.push(formatStep(step, i + 1));
+  }
+  return lines.join("\n");
+}
+
+function buildUserTurnContent(edgePrompt: string, summary: string): string {
+  const parts: string[] = [];
+  if (edgePrompt !== "") {
+    parts.push(edgePrompt);
+  }
+  if (summary !== "") {
+    if (parts.length > 0) {
+      parts.push("");
+    }
+    parts.push(summary);
+  }
+  return parts.join("\n");
+}
+
+/**
+ * Reconstruct multi-turn chat messages from thread history for cache-friendly session resume.
+ *
+ * - system: role prompt + output format (stable prefix)
+ * - For each prior visit of this role: user (edgePrompt + inter-step summary) + assistant (output JSON)
+ * - Final user: current edgePrompt + summary since last visit of this role
+ */
+export function buildBuiltinMessages(ctx: AgentContext): ChatMessage[] {
+  const roleDef = ctx.workflow.roles[ctx.role];
+  const rolePrompt = roleDef !== undefined ? buildRolePrompt(roleDef) : "";
+  const systemParts: string[] = [];
+  if (ctx.outputFormatInstruction !== "") {
+    systemParts.push(ctx.outputFormatInstruction, "");
+  }
+  systemParts.push(rolePrompt);
+
+  systemParts.push(
+    "",
+    "## Workflow",
+    "",
+    `Your working directory is: ${process.cwd()}`,
+    "",
+    "You have tools available (read_file, write_file, run_command). " +
+      "Use them to complete your task — read files, run commands, make changes as needed. " +
+      "Your task is described in the user message below — do NOT use uwf or workflow CLI commands to discover your task. " +
+      "When you are done, output your final response with the YAML frontmatter block as specified above. " +
+      "Do NOT output the frontmatter until you have completed all necessary work. " +
+      "If you are running low on turns and cannot finish, output the frontmatter with `status: failed` and explain what remains in the body. " +
+      "CRITICAL: Your final output MUST start with the `---` fence on the very first line — " +
+      "no preamble text, no explanation before it. The parser requires `---` at position 0.",
+  );
+
+  const messages: ChatMessage[] = [{ role: "system", content: systemParts.join("\n") }];
+
+  const roleVisitIndices: number[] = [];
+  for (let i = 0; i < ctx.steps.length; i++) {
+    const step = ctx.steps[i];
+    if (step !== undefined && step.role === ctx.role) {
+      roleVisitIndices.push(i);
+    }
+  }
+
+  let prevVisitIndex = -1;
+  for (const visitIndex of roleVisitIndices) {
+    const visitStep = ctx.steps[visitIndex];
+    if (visitStep === undefined) {
+      continue;
+    }
+
+    const summary = buildStepsSummary(ctx.steps, prevVisitIndex + 1, visitIndex);
+    messages.push({
+      role: "user",
+      content: buildUserTurnContent(visitStep.edgePrompt, summary),
+    });
+    messages.push({
+      role: "assistant",
+      content: JSON.stringify(visitStep.output),
+      tool_calls: null,
+    });
+    prevVisitIndex = visitIndex;
+  }
+
+  const finalSummary = buildStepsSummary(ctx.steps, prevVisitIndex + 1, ctx.steps.length);
+  messages.push({
+    role: "user",
+    content: buildUserTurnContent(ctx.edgePrompt, finalSummary),
+  });
+
+  return messages;
+}
@@ -0,0 +1,45 @@
+import type { JSONSchema } from "@uncaged/json-cas";
+
+const BUILTIN_TOOL_CALL_SCHEMA: JSONSchema = {
+  type: "object",
+  required: ["name", "args"],
+  properties: {
+    name: { type: "string" },
+    args: { type: "string" },
+  },
+  additionalProperties: false,
+};
+
+export const BUILTIN_TURN_SCHEMA: JSONSchema = {
+  title: "builtin-turn",
+  type: "object",
+  required: ["role", "content"],
+  properties: {
+    role: { type: "string", enum: ["assistant", "tool"] },
+    content: { type: "string" },
+    toolCalls: {
+      anyOf: [{ type: "array", items: BUILTIN_TOOL_CALL_SCHEMA }, { type: "null" }],
+    },
+    reasoning: {
+      anyOf: [{ type: "string" }, { type: "null" }],
+    },
+  },
+  additionalProperties: false,
+};
+
+export const BUILTIN_DETAIL_SCHEMA: JSONSchema = {
+  title: "builtin-detail",
+  type: "object",
+  required: ["sessionId", "model", "duration", "turnCount", "turns"],
+  properties: {
+    sessionId: { type: "string" },
+    model: { type: "string" },
+    duration: { type: "integer" },
+    turnCount: { type: "integer" },
+    turns: {
+      type: "array",
+      items: { type: "string", format: "cas_ref" },
+    },
+  },
+  additionalProperties: false,
+};
@@ -0,0 +1,59 @@
+import { appendFile, mkdir, readFile, rm } from "node:fs/promises";
+import { join } from "node:path";
+
+import { createLogger } from "@uncaged/workflow-util";
+
+import type { BuiltinTurnPayload } from "./types.js";
+
+const log = createLogger({ sink: { kind: "stderr" } });
+
+function sessionsDir(storageRoot: string): string {
+  return join(storageRoot, "sessions");
+}
+
+function sessionFile(storageRoot: string, sessionId: string): string {
+  return join(sessionsDir(storageRoot), `${sessionId}.jsonl`);
+}
+
+/** Ensure sessions directory exists. */
+export async function initSessionDir(storageRoot: string): Promise<void> {
+  await mkdir(sessionsDir(storageRoot), { recursive: true });
+}
+
+/** Append a turn to the session jsonl file. */
+export async function appendSessionTurn(
+  storageRoot: string,
+  sessionId: string,
+  turn: BuiltinTurnPayload,
+): Promise<void> {
+  const line = `${JSON.stringify(turn)}\n`;
+  await appendFile(sessionFile(storageRoot, sessionId), line, "utf-8");
+  log("3XQVN8KR", `session ${sessionId} appended ${turn.role} turn`);
+}
+
+/** Read all turns from session jsonl. Returns empty array if file does not exist. */
+export async function readSessionTurns(
+  storageRoot: string,
+  sessionId: string,
+): Promise<BuiltinTurnPayload[]> {
+  try {
+    const content = await readFile(sessionFile(storageRoot, sessionId), "utf-8");
+    const lines = content
+      .trim()
+      .split("\n")
+      .filter((l) => l.length > 0);
+    return lines.map((l) => JSON.parse(l) as BuiltinTurnPayload);
+  } catch {
+    return [];
+  }
+}
+
+/** Remove session jsonl file (called after detail is persisted to step CAS). */
+export async function removeSession(storageRoot: string, sessionId: string): Promise<void> {
+  try {
+    await rm(sessionFile(storageRoot, sessionId));
+    log("7FWDP2MJ", `session ${sessionId} removed`);
+  } catch {
+    // already gone — fine
+  }
+}
@@ -0,0 +1,44 @@
+import type { OpenAiToolDefinition } from "../llm/index.js";
+
+import { readFileTool } from "./read-file.js";
+import { runCommandTool } from "./run-command.js";
+import type { BuiltinTool, ToolContext } from "./types.js";
+import { writeFileTool } from "./write-file.js";
+
+export { resolvePath } from "./path.js";
+export type { BuiltinTool, ToolContext } from "./types.js";
+
+const BUILTIN_TOOLS: BuiltinTool[] = [readFileTool, writeFileTool, runCommandTool];
+
+export function getBuiltinTools(): readonly BuiltinTool[] {
+  return BUILTIN_TOOLS;
+}
+
+export function builtinToolsToOpenAi(tools: readonly BuiltinTool[]): OpenAiToolDefinition[] {
+  return tools.map((tool) => ({
+    type: "function",
+    function: {
+      name: tool.name,
+      description: tool.description,
+      parameters: tool.parameters as Record<string, unknown>,
+    },
+  }));
+}
+
+export async function executeBuiltinTool(
+  name: string,
+  argsJson: string,
+  ctx: ToolContext,
+): Promise<string> {
+  const tool = BUILTIN_TOOLS.find((t) => t.name === name);
+  if (tool === undefined) {
+    return `Error: unknown tool ${name}`;
+  }
+  let args: unknown;
+  try {
+    args = JSON.parse(argsJson) as unknown;
+  } catch {
+    return "Error: tool arguments must be valid JSON";
+  }
+  return tool.execute(args, ctx);
+}
@@ -0,0 +1,6 @@
+import { resolve } from "node:path";
+
+/** Resolve a path relative to the working directory. */
+export function resolvePath(cwd: string, inputPath: string): string {
+  return resolve(cwd, inputPath);
+}
@@ -0,0 +1,41 @@
+import { readFile, stat } from "node:fs/promises";
+import { resolvePath } from "./path.js";
+import type { BuiltinTool } from "./types.js";
+
+const MAX_READ_BYTES = 512 * 1024;
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+export const readFileTool: BuiltinTool = {
+  name: "read_file",
+  description: "Read a UTF-8 text file from the workspace.",
+  parameters: {
+    type: "object",
+    required: ["path"],
+    properties: {
+      path: { type: "string", description: "Relative or absolute path within the workspace." },
+    },
+    additionalProperties: false,
+  },
+  execute: async (args, ctx) => {
+    if (!isRecord(args) || typeof args.path !== "string") {
+      return "Error: path must be a string";
+    }
+    const resolved = resolvePath(ctx.cwd, args.path);
+    try {
+      const info = await stat(resolved);
+      if (!info.isFile()) {
+        return "Error: not a file";
+      }
+      if (info.size > MAX_READ_BYTES) {
+        return `Error: file exceeds ${MAX_READ_BYTES} byte limit`;
+      }
+      return await readFile(resolved, "utf8");
+    } catch (cause) {
+      const message = cause instanceof Error ? cause.message : String(cause);
+      return `Error: ${message}`;
+    }
+  },
+};
@@ -0,0 +1,95 @@
+import { spawn } from "node:child_process";
+import { resolvePath } from "./path.js";
+import type { BuiltinTool } from "./types.js";
+
+const COMMAND_TIMEOUT_MS = 60_000;
+const MAX_OUTPUT_CHARS = 32_000;
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+function truncate(text: string, maxChars: number): string {
+  if (text.length <= maxChars) {
+    return text;
+  }
+  return `${text.slice(0, maxChars)}\n...(truncated)`;
+}
+
+function runShell(
+  command: string,
+  cwd: string,
+): Promise<{ stdout: string; stderr: string; code: number }> {
+  return new Promise((resolve, reject) => {
+    const child = spawn(command, {
+      cwd,
+      env: process.env,
+      shell: true,
+      stdio: ["ignore", "pipe", "pipe"],
+    });
+
+    let stdout = "";
+    let stderr = "";
+    child.stdout?.on("data", (chunk: Buffer) => {
+      stdout += chunk.toString();
+    });
+    child.stderr?.on("data", (chunk: Buffer) => {
+      stderr += chunk.toString();
+    });
+
+    const timer = setTimeout(() => {
+      child.kill("SIGTERM");
+    }, COMMAND_TIMEOUT_MS);
+
+    child.on("error", (cause) => {
+      clearTimeout(timer);
+      const message = cause instanceof Error ? cause.message : String(cause);
+      reject(new Error(message));
+    });
+
+    child.on("close", (code) => {
+      clearTimeout(timer);
+      resolve({ stdout, stderr, code: code ?? 1 });
+    });
+  });
+}
+
+export const runCommandTool: BuiltinTool = {
+  name: "run_command",
+  description: "Run a shell command. Output is truncated to 32KB.",
+  parameters: {
+    type: "object",
+    required: ["command"],
+    properties: {
+      command: { type: "string", description: "Shell command to execute." },
+      cwd: {
+        type: "string",
+        description: "Optional working directory relative to workspace root.",
+      },
+    },
+    additionalProperties: false,
+  },
+  execute: async (args, ctx) => {
+    if (!isRecord(args) || typeof args.command !== "string") {
+      return "Error: command must be a string";
+    }
+    let workDir = ctx.cwd;
+    if (args.cwd !== undefined && args.cwd !== null) {
+      if (typeof args.cwd !== "string") {
+        return "Error: cwd must be a string";
+      }
+      workDir = resolvePath(ctx.cwd, args.cwd);
+    }
+    try {
+      const { stdout, stderr, code } = await runShell(args.command, workDir);
+      const out = truncate(
+        `exit_code: ${code}\n--- stdout ---\n${stdout}\n--- stderr ---\n${stderr}`,
+        MAX_OUTPUT_CHARS,
+      );
+      return out;
+    } catch (cause) {
+      const message = cause instanceof Error ? cause.message : String(cause);
+      return `Error: ${message}`;
+    }
+  },
+};
@@ -0,0 +1,13 @@
+import type { JSONSchema } from "@uncaged/json-cas";
+
+export type ToolContext = {
+  cwd: string;
+  storageRoot: string;
+};
+
+export type BuiltinTool = {
+  name: string;
+  description: string;
+  parameters: JSONSchema;
+  execute: (args: unknown, ctx: ToolContext) => Promise<string>;
+};
@@ -0,0 +1,36 @@
+import { mkdir, writeFile } from "node:fs/promises";
+import { dirname } from "node:path";
+import { resolvePath } from "./path.js";
+import type { BuiltinTool } from "./types.js";
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+export const writeFileTool: BuiltinTool = {
+  name: "write_file",
+  description: "Write UTF-8 text to a file in the workspace (creates parent directories).",
+  parameters: {
+    type: "object",
+    required: ["path", "content"],
+    properties: {
+      path: { type: "string", description: "Relative or absolute path within the workspace." },
+      content: { type: "string", description: "File contents to write." },
+    },
+    additionalProperties: false,
+  },
+  execute: async (args, ctx) => {
+    if (!isRecord(args) || typeof args.path !== "string" || typeof args.content !== "string") {
+      return "Error: path and content must be strings";
+    }
+    const resolved = resolvePath(ctx.cwd, args.path);
+    try {
+      await mkdir(dirname(resolved), { recursive: true });
+      await writeFile(resolved, args.content, "utf8");
+      return `Wrote ${args.content.length} bytes to ${args.path}`;
+    } catch (cause) {
+      const message = cause instanceof Error ? cause.message : String(cause);
+      return `Error: ${message}`;
+    }
+  },
+};
@@ -0,0 +1,49 @@
+import type { ChatMessage } from "./llm/index.js";
+
+export type BuiltinToolCallRecord = {
+  id: string;
+  name: string;
+  args: string;
+};
+
+export type BuiltinToolResultRecord = {
+  toolCallId: string;
+  name: string;
+  content: string;
+};
+
+export type BuiltinLoopTurn = {
+  assistantContent: string | null;
+  toolCalls: BuiltinToolCallRecord[] | null;
+  toolResults: BuiltinToolResultRecord[] | null;
+};
+
+export type BuiltinSessionState = {
+  sessionId: string;
+  model: string;
+  startedAtMs: number;
+  messages: ChatMessage[];
+  turns: BuiltinLoopTurn[];
+};
+
+export type BuiltinTurnRole = "assistant" | "tool";
+
+export type BuiltinToolCall = {
+  name: string;
+  args: string;
+};
+
+export type BuiltinTurnPayload = {
+  role: BuiltinTurnRole;
+  content: string;
+  toolCalls: BuiltinToolCall[] | null;
+  reasoning: string | null;
+};
+
+export type BuiltinDetailPayload = {
+  sessionId: string;
+  model: string;
+  duration: number;
+  turnCount: number;
+  turns: string[];
+};
@@ -0,0 +1,9 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "dist"
+  },
+  "include": ["src"],
+  "references": [{ "path": "../workflow-agent-kit" }, { "path": "../workflow-util" }]
+}
@@ -0,0 +1,91 @@
+# @uncaged/workflow-agent-claude-code
+
+`uwf-claude-code` agent — spawns the Claude Code CLI and captures session detail.
+
+## Overview
+
+Layer 3 agent implementation. Spawns the `claude` CLI with a composed system prompt (role definition, task, prior steps, edge prompt). Parses stream or JSON stdout, caches session IDs for multi-turn continuation, and stores raw output plus structured detail in CAS.
+
+**Dependencies:** `@uncaged/json-cas`, `@uncaged/workflow-agent-kit`
+
+## Installation
+
+Included as the `uwf-claude-code` binary when you install `@uncaged/workflow-agent-claude-code`:
+
+```bash
+bun add -g @uncaged/workflow-agent-claude-code
+```
+
+Requires the `claude` CLI on `PATH`.
+
+## CLI Usage
+
+Invoked by `uwf thread step`:
+
+```bash
+uwf-claude-code <thread-id> <role>
+```
+
+Configure or override the agent:
+
+```bash
+uwf setup --agent claude-code
+uwf thread step <thread-id> --agent uwf-claude-code
+```
+
+Environment variables set by the engine:
+
+| Variable | Purpose |
+|----------|---------|
+| `UWF_EDGE_PROMPT` | Moderator edge instruction for this step |
+
+## API
+
+All exports come from `src/index.ts`.
+
+### Agent factory
+
+```typescript
+function createClaudeCodeAgent(): () => Promise<void>
+function buildClaudeCodePrompt(ctx: AgentContext): string
+```
+
+### Session detail
+
+```typescript
+function parseClaudeCodeStreamOutput(stdout: string): ClaudeCodeParsedResult | null
+function parseClaudeCodeJsonOutput(stdout: string): ClaudeCodeParsedResult | null
+function storeClaudeCodeDetail(
+  store: Store,
+  parsed: ClaudeCodeParsedResult,
+  sessionId: string,
+): Promise<string>
+function storeClaudeCodeRawOutput(store: Store, rawOutput: string): Promise<string>
+```
+
+## Usage (library)
+
+```typescript
+import { createClaudeCodeAgent, buildClaudeCodePrompt } from "@uncaged/workflow-agent-claude-code";
+
+const main = createClaudeCodeAgent();
+void main();
+```
+
+## Internal Structure
+
+```
+src/
+├── index.ts
+├── cli.ts              Binary entrypoint
+├── claude-code.ts      createClaudeCodeAgent, buildClaudeCodePrompt, spawn logic
+├── session-detail.ts   Parse stdout, store CAS detail nodes
+├── schemas.ts          Claude Code detail CAS schemas
+└── types.ts            ClaudeCodeParsedResult, message shapes
+```
+
+## Configuration
+
+Uses session caching from `@uncaged/workflow-agent-kit` (`getCachedSessionId` / `setCachedSessionId`). No separate config file — relies on the Claude Code CLI's own authentication.
+
+Maximum turns per invocation: 90 (constant in `claude-code.ts`).
@@ -41,7 +41,15 @@ describe("buildClaudeCodePrompt", () => {

  test("includes previous steps as history summary", () => {
    const ctx = makeCtx({
-      steps: [{ role: "planner", output: '{"plan":"do X"}', agent: "hermes" }],
+      steps: [
+        {
+          role: "planner",
+          output: '{"plan":"do X"}',
+          agent: "hermes",
+          detail: "detail-1",
+          edgePrompt: "Create a plan.",
+        },
+      ],
    });
    const result = buildClaudeCodePrompt(ctx);
    expect(result).toContain("## Previous Steps");
@@ -2,6 +2,7 @@ import { describe, expect, test } from "bun:test";
 import { createMemoryStore, walk } from "@uncaged/json-cas";
 import {
  parseClaudeCodeJsonOutput,
+  parseClaudeCodeStreamOutput,
  storeClaudeCodeDetail,
  storeClaudeCodeRawOutput,
 } from "../src/session-detail.js";
@@ -17,6 +18,8 @@ describe("parseClaudeCodeJsonOutput", () => {
      num_turns: 3,
      total_cost_usd: 0.08,
      duration_ms: 10276,
+      stop_reason: "end_turn",
+      usage: { input_tokens: 100, output_tokens: 50 },
    });
    const parsed = parseClaudeCodeJsonOutput(stdout);
    expect(parsed).not.toBeNull();
@@ -27,22 +30,10 @@ describe("parseClaudeCodeJsonOutput", () => {
    expect(parsed!.numTurns).toBe(3);
    expect(parsed!.totalCostUsd).toBe(0.08);
    expect(parsed!.durationMs).toBe(10276);
-  });
-
-  test("parses error_max_turns result", () => {
-    const stdout = JSON.stringify({
-      type: "result",
-      subtype: "error_max_turns",
-      result: "Ran out of turns",
-      session_id: "abc-def",
-      num_turns: 90,
-      total_cost_usd: 1.5,
-      duration_ms: 50000,
-    });
-    const parsed = parseClaudeCodeJsonOutput(stdout);
-    expect(parsed).not.toBeNull();
-    expect(parsed!.subtype).toBe("error_max_turns");
-    expect(parsed!.result).toBe("Ran out of turns");
+    expect(parsed!.stopReason).toBe("end_turn");
+    expect(parsed!.usage.inputTokens).toBe(100);
+    expect(parsed!.usage.outputTokens).toBe(50);
+    expect(parsed!.turns).toEqual([]);
  });

  test("returns null for non-JSON output", () => {
@@ -57,45 +48,253 @@ describe("parseClaudeCodeJsonOutput", () => {
  });
 });

-describe("storeClaudeCodeDetail", () => {
-  test("stores claude-code-detail CAS node and returns output + detailHash", async () => {
-    const store = createMemoryStore();
-    const parsed: ClaudeCodeParsedResult = {
-      type: "result",
-      subtype: "success",
-      result: "The answer",
-      sessionId: "abc-123",
-      numTurns: 5,
-      totalCostUsd: 0.12,
-      durationMs: 15000,
-    };
+describe("parseClaudeCodeStreamOutput", () => {
+  test("parses stream-json output with turns", () => {
+    const lines = [
+      JSON.stringify({
+        type: "system",
+        subtype: "init",
+        session_id: "sess-123",
+        model: "claude-sonnet-4.5",
+        tools: ["Bash", "Read"],
+      }),
+      JSON.stringify({
+        type: "assistant",
+        message: {
+          role: "assistant",
+          content: [
+            { type: "text", text: "I'll list the files." },
+            { type: "tool_use", id: "tool_1", name: "Bash", input: { command: "ls" } },
+          ],
+        },
+        session_id: "sess-123",
+      }),
+      JSON.stringify({
+        type: "user",
+        message: {
+          role: "user",
+          content: [{ type: "tool_result", tool_use_id: "tool_1", content: "file1.ts\nfile2.ts" }],
+        },
+        session_id: "sess-123",
+      }),
+      JSON.stringify({
+        type: "assistant",
+        message: {
+          role: "assistant",
+          content: [{ type: "text", text: "There are 2 files." }],
+        },
+        session_id: "sess-123",
+      }),
+      JSON.stringify({
+        type: "result",
+        subtype: "success",
+        result: "There are 2 files.",
+        session_id: "sess-123",
+        num_turns: 2,
+        total_cost_usd: 0.05,
+        duration_ms: 5000,
+        stop_reason: "end_turn",
+        usage: {
+          input_tokens: 200,
+          output_tokens: 30,
+          cache_read_input_tokens: 100,
+          cache_creation_input_tokens: 0,
+        },
+      }),
+    ];
+    const stdout = lines.join("\n");
+    const parsed = parseClaudeCodeStreamOutput(stdout);
+
+    expect(parsed).not.toBeNull();
+    expect(parsed!.model).toBe("claude-sonnet-4.5");
+    expect(parsed!.sessionId).toBe("sess-123");
+    expect(parsed!.result).toBe("There are 2 files.");
+    expect(parsed!.stopReason).toBe("end_turn");
+    expect(parsed!.usage.inputTokens).toBe(200);
+    expect(parsed!.usage.outputTokens).toBe(30);
+    expect(parsed!.usage.cacheReadInputTokens).toBe(100);
+
+    // Turns: assistant(text+tool), tool_result, assistant(text)
+    expect(parsed!.turns).toHaveLength(3);
+    expect(parsed!.turns[0]!.role).toBe("assistant");
+    expect(parsed!.turns[0]!.content).toBe("I'll list the files.");
+    expect(parsed!.turns[0]!.toolCalls).toHaveLength(1);
+    expect(parsed!.turns[0]!.toolCalls![0]!.name).toBe("Bash");
+    expect(parsed!.turns[1]!.role).toBe("tool_result");
+    expect(parsed!.turns[1]!.content).toBe("file1.ts\nfile2.ts");
+    expect(parsed!.turns[2]!.role).toBe("assistant");
+    expect(parsed!.turns[2]!.content).toBe("There are 2 files.");
+    expect(parsed!.turns[2]!.toolCalls).toBeNull();
+  });
+
+  test("returns null when no result line", () => {
+    const stdout = JSON.stringify({ type: "system", model: "test" });
+    expect(parseClaudeCodeStreamOutput(stdout)).toBeNull();
+  });
+
+  test("skips invalid JSON lines gracefully", () => {
+    const lines = [
+      "not json",
+      JSON.stringify({
+        type: "result",
+        subtype: "success",
+        result: "ok",
+        session_id: "s1",
+        num_turns: 1,
+        total_cost_usd: 0.01,
+        duration_ms: 1000,
+        stop_reason: "end_turn",
+        usage: {},
+      }),
+    ];
+    const parsed = parseClaudeCodeStreamOutput(lines.join("\n"));
+    expect(parsed).not.toBeNull();
+    expect(parsed!.result).toBe("ok");
+    expect(parsed!.turns).toHaveLength(0);
+  });
+});
+
+describe("parseClaudeCodeStreamOutput — helper extraction", () => {
+  test("processSystemLine sets model from system message", () => {
+    const lines = [
+      JSON.stringify({ type: "system", model: "claude-opus-4" }),
+      JSON.stringify({
+        type: "result",
+        subtype: "success",
+        result: "ok",
+        session_id: "s1",
+        num_turns: 0,
+        total_cost_usd: 0,
+        duration_ms: 0,
+        stop_reason: "end_turn",
+      }),
+    ];
+    const parsed = parseClaudeCodeStreamOutput(lines.join("\n"));
+    expect(parsed).not.toBeNull();
+    expect(parsed!.model).toBe("claude-opus-4");
+  });
+
+  test("processAssistantLine skips empty content", () => {
+    const lines = [
+      JSON.stringify({ type: "assistant", message: { role: "assistant", content: [] } }),
+      JSON.stringify({
+        type: "result",
+        subtype: "success",
+        result: "ok",
+        session_id: "s1",
+        num_turns: 0,
+        total_cost_usd: 0,
+        duration_ms: 0,
+        stop_reason: "end_turn",
+      }),
+    ];
+    const parsed = parseClaudeCodeStreamOutput(lines.join("\n"));
+    expect(parsed).not.toBeNull();
+    expect(parsed!.turns).toHaveLength(0);
+  });
+
+  test("processUserLine skips when no tool_result items", () => {
+    const lines = [
+      JSON.stringify({
+        type: "user",
+        message: { role: "user", content: [{ type: "text", text: "hi" }] },
+      }),
+      JSON.stringify({
+        type: "result",
+        subtype: "success",
+        result: "ok",
+        session_id: "s1",
+        num_turns: 0,
+        total_cost_usd: 0,
+        duration_ms: 0,
+        stop_reason: "end_turn",
+      }),
+    ];
+    const parsed = parseClaudeCodeStreamOutput(lines.join("\n"));
+    expect(parsed).not.toBeNull();
+    expect(parsed!.turns).toHaveLength(0);
+  });
+
+  test("turn indices are sequential across mixed assistant and user lines", () => {
+    const lines = [
+      JSON.stringify({
+        type: "assistant",
+        message: { role: "assistant", content: [{ type: "text", text: "A" }] },
+      }),
+      JSON.stringify({
+        type: "user",
+        message: { role: "user", content: [{ type: "tool_result", content: "R" }] },
+      }),
+      JSON.stringify({
+        type: "assistant",
+        message: { role: "assistant", content: [{ type: "text", text: "B" }] },
+      }),
+      JSON.stringify({
+        type: "result",
+        subtype: "success",
+        result: "ok",
+        session_id: "s1",
+        num_turns: 3,
+        total_cost_usd: 0,
+        duration_ms: 0,
+        stop_reason: "end_turn",
+      }),
+    ];
+    const parsed = parseClaudeCodeStreamOutput(lines.join("\n"));
+    expect(parsed).not.toBeNull();
+    expect(parsed!.turns).toHaveLength(3);
+    expect(parsed!.turns.map((t) => t.index)).toEqual([0, 1, 2]);
+  });
+});
+
+describe("storeClaudeCodeDetail", () => {
+  const baseParsed: ClaudeCodeParsedResult = {
+    type: "result",
+    subtype: "success",
+    result: "The answer",
+    sessionId: "abc-123",
+    numTurns: 5,
+    totalCostUsd: 0.12,
+    durationMs: 15000,
+    model: "claude-sonnet-4.5",
+    stopReason: "end_turn",
+    usage: {
+      inputTokens: 100,
+      outputTokens: 50,
+      cacheReadInputTokens: 0,
+      cacheCreationInputTokens: 0,
+    },
+    turns: [
+      { index: 0, role: "assistant", content: "hello", toolCalls: null },
+      { index: 1, role: "tool_result", content: "world", toolCalls: null },
+    ],
+  };
+
+  test("stores detail with per-turn CAS nodes", async () => {
+    const store = createMemoryStore();
+    const { detailHash, output, sessionId } = await storeClaudeCodeDetail(store, baseParsed);

-    const { detailHash, output, sessionId } = await storeClaudeCodeDetail(store, parsed);
    expect(detailHash).toHaveLength(13);
    expect(output).toBe("The answer");
    expect(sessionId).toBe("abc-123");

    const node = await store.get(detailHash);
    expect(node).not.toBeNull();
-    expect(node!.payload.sessionId).toBe("abc-123");
-    expect(node!.payload.numTurns).toBe(5);
-    expect(node!.payload.totalCostUsd).toBe(0.12);
-    expect(node!.payload.durationMs).toBe(15000);
+    expect(node!.payload.model).toBe("claude-sonnet-4.5");
+    expect(node!.payload.stopReason).toBe("end_turn");
+    expect(node!.payload.usage.inputTokens).toBe(100);
+    expect(node!.payload.turns).toHaveLength(2);
+
+    // Verify turn CAS nodes
+    const turn0 = await store.get(node!.payload.turns[0]);
+    expect(turn0).not.toBeNull();
+    expect(turn0!.payload.role).toBe("assistant");
+    expect(turn0!.payload.content).toBe("hello");
  });

  test("detail node is walkable from root", async () => {
    const store = createMemoryStore();
-    const parsed: ClaudeCodeParsedResult = {
-      type: "result",
-      subtype: "success",
-      result: "walkable test",
-      sessionId: "walk-123",
-      numTurns: 1,
-      totalCostUsd: 0.01,
-      durationMs: 1000,
-    };
-
-    const { detailHash } = await storeClaudeCodeDetail(store, parsed);
+    const { detailHash } = await storeClaudeCodeDetail(store, baseParsed);
    const visited: string[] = [];
    walk(store, detailHash, (hash) => visited.push(hash));
    expect(visited.length).toBeGreaterThan(0);
@@ -1,17 +1,22 @@
 import { spawn } from "node:child_process";
 import type { Store } from "@uncaged/json-cas";
-
 import {
  type AgentContext,
  type AgentRunResult,
  buildRolePrompt,
  createAgent,
+  getCachedSessionId,
+  setCachedSessionId,
 } from "@uncaged/workflow-agent-kit";
+import { createLogger } from "@uncaged/workflow-util";

-import { parseClaudeCodeJsonOutput, storeClaudeCodeDetail } from "./session-detail.js";
+import { parseClaudeCodeStreamOutput, storeClaudeCodeDetail } from "./session-detail.js";
+
+const log = createLogger({ sink: { kind: "stderr" } });

 const CLAUDE_COMMAND = "claude";
 const CLAUDE_MAX_TURNS = 90;
+const CLAUDE_MODEL = process.env.CLAUDE_MODEL ?? null;

 function buildHistorySummary(steps: AgentContext["steps"]): string {
  if (steps.length === 0) {
@@ -45,6 +50,7 @@ export function buildClaudeCodePrompt(ctx: AgentContext): string {
  if (historyBlock !== "") {
    parts.push("", historyBlock);
  }
+  parts.push("", "## Current Instruction", "", ctx.edgePrompt);
  return parts.join("\n");
 }

@@ -82,36 +88,46 @@ function spawnClaude(args: string[]): Promise<{ stdout: string; stderr: string }
 }

 function spawnClaudeRun(prompt: string): Promise<{ stdout: string; stderr: string }> {
-  return spawnClaude([
+  const args = [
    "-p",
    prompt,
    "--output-format",
-    "json",
+    "stream-json",
+    "--verbose",
    "--dangerously-skip-permissions",
    "--max-turns",
    String(CLAUDE_MAX_TURNS),
-  ]);
+  ];
+  if (CLAUDE_MODEL !== null) {
+    args.push("--model", CLAUDE_MODEL);
+  }
+  return spawnClaude(args);
 }

 function spawnClaudeResume(
  sessionId: string,
  message: string,
 ): Promise<{ stdout: string; stderr: string }> {
-  return spawnClaude([
+  const args = [
    "-p",
    message,
    "--resume",
    sessionId,
    "--output-format",
-    "json",
+    "stream-json",
+    "--verbose",
    "--dangerously-skip-permissions",
    "--max-turns",
    String(CLAUDE_MAX_TURNS),
-  ]);
+  ];
+  if (CLAUDE_MODEL !== null) {
+    args.push("--model", CLAUDE_MODEL);
+  }
+  return spawnClaude(args);
 }

 async function processClaudeOutput(stdout: string, store: Store): Promise<AgentRunResult> {
-  const parsed = parseClaudeCodeJsonOutput(stdout);
+  const parsed = parseClaudeCodeStreamOutput(stdout);

  if (parsed !== null) {
    const { detailHash, output, sessionId } = await storeClaudeCodeDetail(store, parsed);
@@ -119,14 +135,43 @@ async function processClaudeOutput(stdout: string, store: Store): Promise<AgentR
  }

  throw new Error(
-    `Claude Code returned non-JSON output (first 200 chars): ${stdout.slice(0, 200)}`,
+    `Claude Code returned unparseable output (first 200 chars): ${stdout.slice(0, 200)}`,
  );
 }

 async function runClaudeCode(ctx: AgentContext): Promise<AgentRunResult> {
  const fullPrompt = buildClaudeCodePrompt(ctx);
+
+  log("K7R2M4N8", `prompt for role=${ctx.role} (length=${fullPrompt.length}):\n${fullPrompt}`);
+
+  // Try resuming a cached session for re-entry scenarios (e.g. reviewer reject → developer re-entry).
+  if (!ctx.isFirstVisit) {
+    const cachedSessionId = await getCachedSessionId("claude-code", ctx.threadId, ctx.role);
+    if (cachedSessionId !== null) {
+      try {
+        const { stdout } = await spawnClaudeResume(cachedSessionId, fullPrompt);
+        const result = await processClaudeOutput(stdout, ctx.store);
+        if (result.sessionId !== undefined && result.sessionId !== "") {
+          await setCachedSessionId("claude-code", ctx.threadId, ctx.role, result.sessionId);
+        }
+        return result;
+      } catch (err) {
+        log(
+          "5VKR8N3Q",
+          "resume failed for session %s, falling back to fresh run: %s",
+          cachedSessionId,
+          err,
+        );
+      }
+    }
+  }
+
  const { stdout } = await spawnClaudeRun(fullPrompt);
-  return processClaudeOutput(stdout, ctx.store);
+  const result = await processClaudeOutput(stdout, ctx.store);
+  if (result.sessionId !== undefined && result.sessionId !== "") {
+    await setCachedSessionId("claude-code", ctx.threadId, ctx.role, result.sessionId);
+  }
+  return result;
 }

 async function continueClaudeCode(
@@ -1,6 +1,7 @@
 export { buildClaudeCodePrompt, createClaudeCodeAgent } from "./claude-code.js";
 export {
  parseClaudeCodeJsonOutput,
+  parseClaudeCodeStreamOutput,
  storeClaudeCodeDetail,
  storeClaudeCodeRawOutput,
 } from "./session-detail.js";
@@ -3,13 +3,52 @@ import type { JSONSchema } from "@uncaged/json-cas";
 export const CLAUDE_CODE_DETAIL_SCHEMA: JSONSchema = {
  title: "claude-code-detail",
  type: "object",
-  required: ["sessionId", "numTurns", "totalCostUsd", "durationMs", "subtype"],
+  required: [
+    "sessionId",
+    "model",
+    "subtype",
+    "durationMs",
+    "numTurns",
+    "totalCostUsd",
+    "stopReason",
+    "usage",
+    "turns",
+  ],
  properties: {
    sessionId: { type: "string" },
+    model: { type: "string" },
+    subtype: { type: "string" },
+    durationMs: { type: "integer" },
    numTurns: { type: "integer" },
    totalCostUsd: { type: "number" },
-    durationMs: { type: "integer" },
-    subtype: { type: "string" },
+    stopReason: { type: "string" },
+    usage: {
+      type: "object",
+      properties: {
+        inputTokens: { type: "integer" },
+        outputTokens: { type: "integer" },
+        cacheReadInputTokens: { type: "integer" },
+        cacheCreationInputTokens: { type: "integer" },
+      },
+      required: ["inputTokens", "outputTokens", "cacheReadInputTokens", "cacheCreationInputTokens"],
+    },
+    turns: {
+      type: "array",
+      items: { type: "string", format: "cas_ref" },
+    },
+  },
+  additionalProperties: false,
+};
+
+export const CLAUDE_CODE_TURN_SCHEMA: JSONSchema = {
+  title: "claude-code-turn",
+  type: "object",
+  required: ["index", "role", "content", "toolCalls"],
+  properties: {
+    index: { type: "integer" },
+    role: { type: "string" },
+    content: { type: "string" },
+    toolCalls: {},
  },
  additionalProperties: false,
 };
@@ -1,13 +1,175 @@
 import { bootstrap, putSchema, type Store } from "@uncaged/json-cas";

-import { CLAUDE_CODE_DETAIL_SCHEMA, CLAUDE_CODE_RAW_OUTPUT_SCHEMA } from "./schemas.js";
-import type { ClaudeCodeDetailPayload, ClaudeCodeParsedResult } from "./types.js";
+import {
+  CLAUDE_CODE_DETAIL_SCHEMA,
+  CLAUDE_CODE_RAW_OUTPUT_SCHEMA,
+  CLAUDE_CODE_TURN_SCHEMA,
+} from "./schemas.js";
+import type {
+  ClaudeCodeDetailPayload,
+  ClaudeCodeParsedResult,
+  ClaudeCodeToolCall,
+  ClaudeCodeTurnPayload,
+} from "./types.js";

 function isRecord(value: unknown): value is Record<string, unknown> {
  return typeof value === "object" && value !== null && !Array.isArray(value);
 }

-/** Parse Claude Code JSON stdout (`claude -p --output-format json`). */
+function safeNumber(v: unknown, fallback = 0): number {
+  return typeof v === "number" ? v : fallback;
+}
+
+function safeString(v: unknown, fallback = ""): string {
+  return typeof v === "string" ? v : fallback;
+}
+
+/**
+ * Extract tool calls from an assistant message content array.
+ */
+function extractToolCalls(content: unknown[]): ClaudeCodeToolCall[] {
+  const calls: ClaudeCodeToolCall[] = [];
+  for (const item of content) {
+    if (isRecord(item) && item.type === "tool_use" && typeof item.name === "string") {
+      calls.push({
+        name: item.name,
+        input: typeof item.input === "string" ? item.input : JSON.stringify(item.input ?? {}),
+      });
+    }
+  }
+  return calls;
+}
+
+/**
+ * Extract text content from a message content array.
+ */
+function extractTextContent(content: unknown[]): string {
+  const texts: string[] = [];
+  for (const item of content) {
+    if (isRecord(item) && item.type === "text" && typeof item.text === "string") {
+      texts.push(item.text);
+    }
+  }
+  return texts.join("\n");
+}
+
+/**
+ * Extract tool result content from a user message content array.
+ */
+function extractToolResultContent(content: unknown[]): string {
+  const results: string[] = [];
+  for (const item of content) {
+    if (isRecord(item) && item.type === "tool_result") {
+      const text = typeof item.content === "string" ? item.content : "";
+      results.push(text);
+    }
+  }
+  return results.join("\n");
+}
+
+type ParseState = {
+  turns: ClaudeCodeTurnPayload[];
+  resultLine: Record<string, unknown> | null;
+  model: string;
+  turnIndex: number;
+};
+
+function processSystemLine(parsed: Record<string, unknown>, state: ParseState): void {
+  if (typeof parsed.model === "string") {
+    state.model = parsed.model;
+  }
+}
+
+function processAssistantLine(parsed: Record<string, unknown>, state: ParseState): void {
+  if (!isRecord(parsed.message)) return;
+  const content = Array.isArray(parsed.message.content) ? parsed.message.content : [];
+  const textContent = extractTextContent(content as unknown[]);
+  const toolCalls = extractToolCalls(content as unknown[]);
+  if (textContent !== "" || toolCalls.length > 0) {
+    state.turns.push({
+      index: state.turnIndex++,
+      role: "assistant",
+      content: textContent,
+      toolCalls: toolCalls.length > 0 ? toolCalls : null,
+    });
+  }
+}
+
+function processUserLine(parsed: Record<string, unknown>, state: ParseState): void {
+  if (!isRecord(parsed.message)) return;
+  const content = Array.isArray(parsed.message.content) ? parsed.message.content : [];
+  const resultContent = extractToolResultContent(content as unknown[]);
+  if (resultContent !== "") {
+    state.turns.push({
+      index: state.turnIndex++,
+      role: "tool_result",
+      content: resultContent,
+      toolCalls: null,
+    });
+  }
+}
+
+function processLine(line: string, state: ParseState): void {
+  let parsed: unknown;
+  try {
+    parsed = JSON.parse(line);
+  } catch {
+    return;
+  }
+  if (!isRecord(parsed)) return;
+  const type = parsed.type;
+  if (type === "system") processSystemLine(parsed, state);
+  else if (type === "assistant") processAssistantLine(parsed, state);
+  else if (type === "user") processUserLine(parsed, state);
+  else if (type === "result") state.resultLine = parsed;
+}
+
+function assembleResult(state: ParseState): ClaudeCodeParsedResult | null {
+  if (state.resultLine === null) return null;
+  const sessionId = state.resultLine.session_id;
+  const result = state.resultLine.result;
+  const subtype = state.resultLine.subtype;
+  if (typeof sessionId !== "string" || typeof result !== "string" || typeof subtype !== "string") {
+    return null;
+  }
+  const usage = isRecord(state.resultLine.usage) ? state.resultLine.usage : {};
+  return {
+    type: safeString(state.resultLine.type, "result"),
+    subtype: subtype as ClaudeCodeParsedResult["subtype"],
+    result,
+    sessionId,
+    numTurns: safeNumber(state.resultLine.num_turns),
+    totalCostUsd: safeNumber(state.resultLine.total_cost_usd),
+    durationMs: safeNumber(state.resultLine.duration_ms),
+    model: state.model,
+    stopReason: safeString(state.resultLine.stop_reason),
+    usage: {
+      inputTokens: safeNumber(usage.input_tokens),
+      outputTokens: safeNumber(usage.output_tokens),
+      cacheReadInputTokens: safeNumber(usage.cache_read_input_tokens),
+      cacheCreationInputTokens: safeNumber(usage.cache_creation_input_tokens),
+    },
+    turns: state.turns,
+  };
+}
+
+/**
+ * Parse Claude Code stream-json (NDJSON) output.
+ * Each line is a JSON object with type: "system" | "assistant" | "user" | "result".
+ */
+export function parseClaudeCodeStreamOutput(stdout: string): ClaudeCodeParsedResult | null {
+  const lines = stdout.trim().split("\n");
+  const state: ParseState = { turns: [], resultLine: null, model: "", turnIndex: 0 };
+  for (const line of lines) {
+    processLine(line, state);
+  }
+  return assembleResult(state);
+}
+
+/**
+ * Legacy: parse Claude Code plain JSON output (non-streaming).
+ * Falls back when stream-json is not available.
+ */
 export function parseClaudeCodeJsonOutput(stdout: string): ClaudeCodeParsedResult | null {
  let parsed: unknown;
  try {
@@ -16,9 +178,7 @@ export function parseClaudeCodeJsonOutput(stdout: string): ClaudeCodeParsedResul
    return null;
  }

-  if (!isRecord(parsed)) {
-    return null;
-  }
+  if (!isRecord(parsed)) return null;

  const sessionId = parsed.session_id;
  const result = parsed.result;
@@ -28,44 +188,68 @@ export function parseClaudeCodeJsonOutput(stdout: string): ClaudeCodeParsedResul
    return null;
  }

+  const usage = isRecord(parsed.usage) ? parsed.usage : {};
+
  return {
-    type: typeof parsed.type === "string" ? parsed.type : "result",
+    type: safeString(parsed.type, "result"),
    subtype: subtype as ClaudeCodeParsedResult["subtype"],
    result,
    sessionId,
-    numTurns: typeof parsed.num_turns === "number" ? parsed.num_turns : 0,
-    totalCostUsd: typeof parsed.total_cost_usd === "number" ? parsed.total_cost_usd : 0,
-    durationMs: typeof parsed.duration_ms === "number" ? parsed.duration_ms : 0,
+    numTurns: safeNumber(parsed.num_turns),
+    totalCostUsd: safeNumber(parsed.total_cost_usd),
+    durationMs: safeNumber(parsed.duration_ms),
+    model: "",
+    stopReason: safeString(parsed.stop_reason),
+    usage: {
+      inputTokens: safeNumber(usage.input_tokens),
+      outputTokens: safeNumber(usage.output_tokens),
+      cacheReadInputTokens: safeNumber(usage.cache_read_input_tokens),
+      cacheCreationInputTokens: safeNumber(usage.cache_creation_input_tokens),
+    },
+    turns: [],
  };
 }

 type ClaudeCodeSchemaHashes = {
  detail: string;
+  turn: string;
  rawOutput: string;
 };

 async function registerSchemas(store: Store): Promise<ClaudeCodeSchemaHashes> {
  await bootstrap(store);
-  const [detail, rawOutput] = await Promise.all([
+  const [detail, turn, rawOutput] = await Promise.all([
    putSchema(store, CLAUDE_CODE_DETAIL_SCHEMA),
+    putSchema(store, CLAUDE_CODE_TURN_SCHEMA),
    putSchema(store, CLAUDE_CODE_RAW_OUTPUT_SCHEMA),
  ]);
-  return { detail, rawOutput };
+  return { detail, turn, rawOutput };
 }

-/** Store parsed Claude Code result as a CAS detail node. */
+/** Store parsed Claude Code result with per-turn breakdown as CAS detail nodes. */
 export async function storeClaudeCodeDetail(
  store: Store,
  parsed: ClaudeCodeParsedResult,
 ): Promise<{ detailHash: string; output: string; sessionId: string }> {
  const schemas = await registerSchemas(store);

+  // Store each turn as an individual CAS node
+  const turnHashes: string[] = [];
+  for (const turn of parsed.turns) {
+    const hash = await store.put(schemas.turn, turn);
+    turnHashes.push(hash);
+  }
+
  const detail: ClaudeCodeDetailPayload = {
    sessionId: parsed.sessionId,
+    model: parsed.model,
+    subtype: parsed.subtype,
+    durationMs: parsed.durationMs,
    numTurns: parsed.numTurns,
    totalCostUsd: parsed.totalCostUsd,
-    durationMs: parsed.durationMs,
-    subtype: parsed.subtype,
+    stopReason: parsed.stopReason,
+    usage: parsed.usage,
+    turns: turnHashes,
  };

  const detailHash = await store.put(schemas.detail, detail);
@@ -1,5 +1,38 @@
 export type ClaudeCodeResultSubtype = "success" | "error_max_turns" | "error_budget";

+/** A single tool call within an assistant turn. */
+export type ClaudeCodeToolCall = {
+  name: string;
+  input: string;
+};
+
+/** A single turn (assistant text, tool use, or tool result). */
+export type ClaudeCodeTurnPayload = {
+  index: number;
+  role: "assistant" | "tool_result";
+  content: string;
+  toolCalls: ClaudeCodeToolCall[] | null;
+};
+
+/** Top-level detail stored as CAS node. */
+export type ClaudeCodeDetailPayload = {
+  sessionId: string;
+  model: string;
+  subtype: string;
+  durationMs: number;
+  numTurns: number;
+  totalCostUsd: number;
+  stopReason: string;
+  usage: {
+    inputTokens: number;
+    outputTokens: number;
+    cacheReadInputTokens: number;
+    cacheCreationInputTokens: number;
+  };
+  turns: string[]; // CAS hashes of ClaudeCodeTurnPayload
+};
+
+/** Intermediate parsed result from stream-json output. */
 export type ClaudeCodeParsedResult = {
  type: string;
  subtype: ClaudeCodeResultSubtype;
@@ -8,12 +41,13 @@ export type ClaudeCodeParsedResult = {
  numTurns: number;
  totalCostUsd: number;
  durationMs: number;
-};
-
-export type ClaudeCodeDetailPayload = {
-  sessionId: string;
-  numTurns: number;
-  totalCostUsd: number;
-  durationMs: number;
-  subtype: string;
+  model: string;
+  stopReason: string;
+  usage: {
+    inputTokens: number;
+    outputTokens: number;
+    cacheReadInputTokens: number;
+    cacheCreationInputTokens: number;
+  };
+  turns: ClaudeCodeTurnPayload[];
 };
@@ -0,0 +1,90 @@
+# @uncaged/workflow-agent-hermes
+
+`uwf-hermes` agent — spawns Hermes chat via ACP and captures session detail.
+
+## Overview
+
+Layer 3 agent implementation. Wraps the Hermes CLI using the Agent Client Protocol (ACP). On first visit to a role it sends a composed prompt (role definition, task, history, edge prompt); on continuation it resumes the cached session. Session transcripts and raw output are stored as CAS detail nodes.
+
+**Dependencies:** `@uncaged/json-cas`, `@uncaged/workflow-agent-kit`, `@uncaged/workflow-protocol`, `@uncaged/workflow-util`
+
+## Installation
+
+Included as the `uwf-hermes` binary when you install `@uncaged/workflow-agent-hermes`:
+
+```bash
+bun add -g @uncaged/workflow-agent-hermes
+```
+
+Requires the `hermes` CLI on `PATH`.
+
+## CLI Usage
+
+Invoked by `uwf thread step` (not typically run directly):
+
+```bash
+uwf-hermes <thread-id> <role>
+```
+
+Environment variables set by the engine:
+
+| Variable | Purpose |
+|----------|---------|
+| `UWF_EDGE_PROMPT` | Moderator edge instruction for this step |
+
+Configure as the default agent via `uwf setup --agent hermes`.
+
+Override per step:
+
+```bash
+uwf thread step <thread-id> --agent uwf-hermes
+```
+
+## API
+
+All exports come from `src/index.ts`.
+
+### Agent factory
+
+```typescript
+function createHermesAgent(): () => Promise<void>
+function buildHermesPrompt(ctx: AgentContext): string
+```
+
+### ACP client
+
+```typescript
+class HermesAcpClient {
+  // Spawns hermes, handles JSON-RPC over stdio
+}
+```
+
+## Usage (library)
+
+```typescript
+import { createHermesAgent, buildHermesPrompt } from "@uncaged/workflow-agent-hermes";
+
+// CLI entry (src/cli.ts):
+const main = createHermesAgent();
+void main();
+```
+
+## Internal Structure
+
+```
+src/
+├── index.ts
+├── cli.ts              Binary entrypoint
+├── hermes.ts           createHermesAgent, buildHermesPrompt
+├── acp-client.ts       HermesAcpClient — ACP JSON-RPC over stdio
+├── session-cache.ts    Session ID cache (re-exports kit helpers + isResumeDisabled)
+├── session-detail.ts   Parse Hermes session JSON, store CAS detail nodes
+├── schemas.ts          Hermes detail CAS schemas
+└── types.ts            HermesSessionJson, HermesSessionMessage
+```
+
+## Configuration
+
+Uses workflow config from `~/.uncaged/workflow/config.yaml` (via agent-kit). Hermes session files are stored under the workflow storage root (see `session-detail.ts`).
+
+Set `UWF_HERMES_NO_RESUME=1` to disable session resume (see `isResumeDisabled` in `session-cache.ts`).
@@ -4,6 +4,96 @@ import { HermesAcpClient } from "../src/acp-client.js";

 const UUID_RE = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;

+describe("handleSessionUpdate — helper extraction", () => {
+  let client: HermesAcpClient;
+
+  beforeEach(() => {
+    client = new HermesAcpClient();
+  });
+
+  afterEach(async () => {
+    await client.close();
+  });
+
+  it("agent_message_chunk accumulates text in messageChunks", () => {
+    (client as any).handleSessionUpdate({
+      sessionUpdate: "agent_message_chunk",
+      content: { type: "text", text: "hello" },
+    });
+    (client as any).handleSessionUpdate({
+      sessionUpdate: "agent_message_chunk",
+      content: { type: "text", text: " world" },
+    });
+    expect((client as any).messageChunks).toEqual(["hello", " world"]);
+  });
+
+  it("agent_thought_chunk accumulates reasoning in reasoningChunks", () => {
+    (client as any).handleSessionUpdate({
+      sessionUpdate: "agent_thought_chunk",
+      content: { type: "text", text: "thinking" },
+    });
+    expect((client as any).reasoningChunks).toEqual(["thinking"]);
+  });
+
+  it("tool_call registers a pending tool and flushes message chunks", () => {
+    (client as any).messageChunks = ["pre-tool text"];
+    (client as any).handleSessionUpdate({
+      sessionUpdate: "tool_call",
+      title: "Bash",
+      rawInput: { command: "ls" },
+      toolCallId: "tc-1",
+    });
+    expect((client as any).pendingTools.get("tc-1")).toEqual({
+      name: "Bash",
+      args: JSON.stringify({ command: "ls" }),
+    });
+    expect((client as any).messageChunks).toEqual([]);
+    expect((client as any).messages).toHaveLength(1);
+    expect((client as any).messages[0].role).toBe("assistant");
+  });
+
+  it("tool_call_update completed pushes tool_call and tool messages", () => {
+    (client as any).pendingTools.set("tc-2", { name: "Read", args: '{"path":"/foo"}' });
+    (client as any).handleSessionUpdate({
+      sessionUpdate: "tool_call_update",
+      status: "completed",
+      toolCallId: "tc-2",
+      rawOutput: "file contents",
+    });
+    const msgs = (client as any).messages as Array<{
+      role: string;
+      tool_calls: unknown;
+      content: string | null;
+    }>;
+    expect(msgs).toHaveLength(2);
+    expect(msgs[0].role).toBe("assistant");
+    expect(msgs[0].tool_calls).toEqual([
+      { function: { name: "Read", arguments: '{"path":"/foo"}' } },
+    ]);
+    expect(msgs[1].role).toBe("tool");
+    expect(msgs[1].content).toBe("file contents");
+    expect((client as any).pendingTools.has("tc-2")).toBe(false);
+  });
+
+  it("tool_call_update with non-string rawOutput JSON-stringifies it", () => {
+    (client as any).pendingTools.set("tc-3", { name: "Fetch", args: "" });
+    (client as any).handleSessionUpdate({
+      sessionUpdate: "tool_call_update",
+      status: "completed",
+      toolCallId: "tc-3",
+      rawOutput: { html: "<p>page</p>" },
+    });
+    const msgs = (client as any).messages as Array<{ role: string; content: string | null }>;
+    expect(msgs[1].content).toBe(JSON.stringify({ html: "<p>page</p>" }));
+  });
+
+  it("unknown updateType is a no-op", () => {
+    (client as any).handleSessionUpdate({ sessionUpdate: "unknown_type", data: {} });
+    expect((client as any).messages).toHaveLength(0);
+    expect((client as any).messageChunks).toHaveLength(0);
+  });
+});
+
 describe("HermesAcpClient", () => {
  let client: HermesAcpClient;

@@ -54,7 +144,8 @@ describe("HermesAcpClient", () => {
    { timeout: 2 * 60 * 1000 },
  );

-  it(
+  // TODO(#435): flaky — depends on live LLM; mock or move to integration suite
+  it.skip(
    "prompt() collects structured messages including tool calls",
    async () => {
      await client.connect(process.cwd());
@@ -49,8 +49,20 @@ describe("buildHermesPrompt", () => {
      isFirstVisit: false,
      edgePrompt: "The reviewer rejected your work. Fix the issues.",
      steps: [
-        { role: "developer", output: { summary: "Initial fix" }, agent: "uwf-hermes" },
-        { role: "reviewer", output: { approved: false }, agent: "uwf-hermes" },
+        {
+          role: "developer",
+          output: { summary: "Initial fix" },
+          agent: "uwf-hermes",
+          detail: "detail-1",
+          edgePrompt: "Implement the fix.",
+        },
+        {
+          role: "reviewer",
+          output: { approved: false },
+          agent: "uwf-hermes",
+          detail: "detail-2",
+          edgePrompt: "Review the code.",
+        },
      ],
    });

@@ -66,7 +78,15 @@ describe("buildHermesPrompt", () => {
    const result = buildHermesPrompt(
      makeCtx({
        isFirstVisit: true,
-        steps: [{ role: "developer", output: { done: true }, agent: "uwf-hermes" }],
+        steps: [
+          {
+            role: "developer",
+            output: { done: true },
+            agent: "uwf-hermes",
+            detail: "detail-1",
+            edgePrompt: "First attempt.",
+          },
+        ],
        edgePrompt: "Retry with a fresh approach.",
      }),
    );
@@ -0,0 +1,57 @@
+import { afterEach, describe, expect, it } from "bun:test";
+
+import { HermesAcpClient } from "../src/acp-client.js";
+
+/**
+ * E2E test for cross-process session resume.
+ *
+ * Simulates the workflow re-entry scenario:
+ * 1. Client A: connect → prompt → close (developer first run)
+ * 2. Client B: resume(sessionId) → prompt (developer re-entry after reviewer reject)
+ *
+ * This is what happens when uwf thread step spawns uwf-hermes twice for the same role.
+ */
+describe("HermesAcpClient cross-process resume", () => {
+  const clients: HermesAcpClient[] = [];
+
+  afterEach(async () => {
+    for (const c of clients) {
+      await c.close();
+    }
+    clients.length = 0;
+  });
+
+  // TODO(#435): flaky — depends on live LLM; mock or move to integration suite
+  it.skip(
+    "resume() after close — second prompt returns non-empty text",
+    async () => {
+      // --- Client A: first run ---
+      const clientA = new HermesAcpClient();
+      clients.push(clientA);
+
+      await clientA.connect(process.cwd());
+      const first = await clientA.prompt(
+        "Remember the secret code: WATERMELON. Reply with exactly: ACKNOWLEDGED",
+      );
+      expect(first.text.length).toBeGreaterThan(0);
+      const sessionId = first.sessionId;
+
+      // Close client A (simulates uwf-hermes process exit)
+      await clientA.close();
+
+      // --- Client B: resume (simulates re-entry) ---
+      const clientB = new HermesAcpClient();
+      clients.push(clientB);
+
+      await clientB.resume(sessionId, process.cwd());
+      const second = await clientB.prompt(
+        "What was the secret code I told you earlier? Reply with just the code word.",
+      );
+
+      // The critical assertion: resumed session produces non-empty output
+      expect(second.text.length).toBeGreaterThan(0);
+      expect(second.sessionId).toBe(sessionId);
+    },
+    { timeout: 3 * 60 * 1000 },
+  );
+});
@@ -245,73 +245,75 @@ export class HermesAcpClient {
  // ---- Session update → structured messages ----

  private handleSessionUpdate(update: Record<string, unknown>): void {
-    const updateType = update.sessionUpdate as string;
-
-    switch (updateType) {
-      case "agent_message_chunk": {
-        const content = update.content as { type?: string; text?: string } | undefined;
-        if (content?.type === "text" && typeof content.text === "string") {
-          this.messageChunks.push(content.text);
-        }
+    switch (update.sessionUpdate as string) {
+      case "agent_message_chunk":
+        this.handleAgentMessageChunk(update);
        break;
-      }
-
-      case "agent_thought_chunk": {
-        const content = update.content as { type?: string; text?: string } | undefined;
-        if (content?.type === "text" && typeof content.text === "string") {
-          this.reasoningChunks.push(content.text);
-        }
+      case "agent_thought_chunk":
+        this.handleAgentThoughtChunk(update);
        break;
-      }
-
-      case "tool_call": {
-        const title = (update.title as string) ?? "";
-        const rawInput = update.rawInput;
-        const args =
-          rawInput !== undefined && rawInput !== null ? JSON.stringify(rawInput) : "";
-        const toolCallId = update.toolCallId as string;
-        this.pendingTools.set(toolCallId, { name: title, args });
-
-        // Flush accumulated assistant text before tool call
-        this.flushAssistantMessage();
+      case "tool_call":
+        this.handleToolCall(update);
        break;
-      }
-
-      case "tool_call_update": {
-        const status = update.status as string | undefined;
-        if (status === "completed" || status === "failed") {
-          const toolCallId = update.toolCallId as string;
-          const pending = this.pendingTools.get(toolCallId);
-          const toolName = pending?.name ?? toolCallId;
-          const rawOutput = update.rawOutput;
-          const outputStr =
-            rawOutput !== undefined && rawOutput !== null
-              ? typeof rawOutput === "string"
-                ? rawOutput
-                : JSON.stringify(rawOutput)
-              : "";
-          this.messages.push({
-            role: "assistant",
-            content: null,
-            reasoning: null,
-            tool_calls: [{ function: { name: toolName, arguments: pending?.args ?? "" } }],
-          });
-          this.messages.push({
-            role: "tool",
-            content: outputStr,
-            reasoning: null,
-            tool_calls: null,
-          });
-          this.pendingTools.delete(toolCallId);
-        }
+      case "tool_call_update":
+        this.handleToolCallUpdate(update);
        break;
-      }
-
      default:
        break;
    }
  }

+  private handleAgentMessageChunk(update: Record<string, unknown>): void {
+    const content = update.content as { type?: string; text?: string } | undefined;
+    if (content?.type === "text" && typeof content.text === "string") {
+      this.messageChunks.push(content.text);
+    }
+  }
+
+  private handleAgentThoughtChunk(update: Record<string, unknown>): void {
+    const content = update.content as { type?: string; text?: string } | undefined;
+    if (content?.type === "text" && typeof content.text === "string") {
+      this.reasoningChunks.push(content.text);
+    }
+  }
+
+  private handleToolCall(update: Record<string, unknown>): void {
+    const title = (update.title as string) ?? "";
+    const rawInput = update.rawInput;
+    const args = rawInput !== undefined && rawInput !== null ? JSON.stringify(rawInput) : "";
+    const toolCallId = update.toolCallId as string;
+    this.pendingTools.set(toolCallId, { name: title, args });
+    this.flushAssistantMessage();
+  }
+
+  private handleToolCallUpdate(update: Record<string, unknown>): void {
+    const status = update.status as string | undefined;
+    if (status !== "completed" && status !== "failed") return;
+    const toolCallId = update.toolCallId as string;
+    const pending = this.pendingTools.get(toolCallId);
+    const toolName = pending?.name ?? toolCallId;
+    const rawOutput = update.rawOutput;
+    const outputStr =
+      rawOutput !== undefined && rawOutput !== null
+        ? typeof rawOutput === "string"
+          ? rawOutput
+          : JSON.stringify(rawOutput)
+        : "";
+    this.messages.push({
+      role: "assistant",
+      content: null,
+      reasoning: null,
+      tool_calls: [{ function: { name: toolName, arguments: pending?.args ?? "" } }],
+    });
+    this.messages.push({
+      role: "tool",
+      content: outputStr,
+      reasoning: null,
+      tool_calls: null,
+    });
+    this.pendingTools.delete(toolCallId);
+  }
+
  /** Flush any accumulated text/reasoning into an assistant message. */
  private flushAssistantMessage(): void {
    const text = this.messageChunks.join("");
@@ -1,62 +1,13 @@
-import { mkdir, readFile, writeFile } from "node:fs/promises";
-import { dirname, join } from "node:path";
+// Re-export session cache from the shared agent-kit package with agent name injected.

-import { resolveStorageRoot } from "@uncaged/workflow-agent-kit";
+import {
+  getCachedSessionId as getCachedSessionIdBase,
+  setCachedSessionId as setCachedSessionIdBase,
+} from "@uncaged/workflow-agent-kit";
 import type { ThreadId } from "@uncaged/workflow-protocol";

-type HermesSessionCache = Record<string, string>;
-
-function getCachePath(): string {
-  return join(resolveStorageRoot(), "cache", "hermes-sessions.json");
-}
-
-function cacheKey(threadId: ThreadId, role: string): string {
-  return `${threadId}:${role}`;
-}
-
-function isRecord(value: unknown): value is Record<string, unknown> {
-  return typeof value === "object" && value !== null && !Array.isArray(value);
-}
-
-async function readCache(): Promise<HermesSessionCache> {
-  const path = getCachePath();
-  try {
-    const text = await readFile(path, "utf8");
-    const raw = JSON.parse(text) as unknown;
-    if (!isRecord(raw)) {
-      return {};
-    }
-    const cache: HermesSessionCache = {};
-    for (const [key, value] of Object.entries(raw)) {
-      if (typeof value === "string" && value !== "") {
-        cache[key] = value;
-      }
-    }
-    return cache;
-  } catch (e) {
-    const err = e as NodeJS.ErrnoException;
-    if (err.code === "ENOENT") {
-      return {};
-    }
-    throw e;
-  }
-}
-
-async function writeCache(cache: HermesSessionCache): Promise<void> {
-  const path = getCachePath();
-  await mkdir(dirname(path), { recursive: true });
-  await writeFile(path, `${JSON.stringify(cache, null, 2)}\n`, "utf8");
-}
-
-export function isResumeDisabled(): boolean {
-  const flag = process.env.UWF_NO_RESUME;
-  return flag !== undefined && flag !== "";
-}
-
 export async function getCachedSessionId(threadId: ThreadId, role: string): Promise<string | null> {
-  const cache = await readCache();
-  const sessionId = cache[cacheKey(threadId, role)];
-  return sessionId ?? null;
+  return getCachedSessionIdBase("hermes", threadId, role);
 }

 export async function setCachedSessionId(
@@ -64,7 +15,20 @@ export async function setCachedSessionId(
  role: string,
  sessionId: string,
 ): Promise<void> {
-  const cache = await readCache();
-  cache[cacheKey(threadId, role)] = sessionId;
-  await writeCache(cache);
+  return setCachedSessionIdBase("hermes", threadId, role, sessionId);
+}
+
+export function isResumeDisabled(): boolean {
+  // Hermes ACP session/resume is broken: _restore fails for custom providers
+  // because resolve_runtime_provider("custom") throws and base_url/api_mode
+  // are lost in the fallback path.  Resume silently creates a new session
+  // (different sessionId, no history), causing empty-text responses.
+  // See: https://github.com/NousResearch/hermes-agent/issues/13489
+  // Disable by default until upstream fixes the bug.  Set UWF_HERMES_RESUME=1
+  // to opt back in.
+  const enableFlag = process.env.UWF_HERMES_RESUME;
+  if (enableFlag === "1" || enableFlag === "true") {
+    return false;
+  }
+  return true;
 }
@@ -0,0 +1,182 @@
+# @uncaged/workflow-agent-kit
+
+Agent framework — `createAgent` factory, context builder, frontmatter fast-path, and LLM extract pipeline.
+
+## Overview
+
+Layer 2 agent framework. Provides the standard entrypoint for all agent CLIs: parse `<thread-id> <role>` from argv, load thread/workflow context from CAS, invoke the agent's `run`/`continue` functions, validate output via frontmatter fast-path or LLM extract, and write a `StepNodePayload` to CAS.
+
+Also exports prompt builders, config/storage helpers, and session ID caching for multi-turn agents.
+
+**Dependencies:** `@uncaged/json-cas`, `@uncaged/json-cas-fs`, `@uncaged/workflow-protocol`, `@uncaged/workflow-util`, `dotenv`, `yaml`
+
+## Installation
+
+```bash
+bun add @uncaged/workflow-agent-kit
+```
+
+## API
+
+All exports come from `src/index.ts`.
+
+### Agent factory
+
+```typescript
+function createAgent(options: AgentOptions): () => Promise<void>
+
+type AgentOptions = {
+  name: string;
+  run: AgentRunFn;
+  continue: AgentContinueFn;
+};
+
+type AgentRunFn = (ctx: AgentContext) => Promise<AgentRunResult>;
+type AgentContinueFn = (
+  sessionId: string,
+  message: string,
+  store: AgentContext["store"],
+) => Promise<AgentRunResult>;
+
+type AgentRunResult = {
+  output: string;
+  detailHash: string;
+  sessionId: string;
+};
+```
+
+Agent CLIs call `createAgent(...)` and invoke the returned function as `main()`.
+
+### Context
+
+```typescript
+function buildContext(threadId: ThreadId, role: string): Promise<AgentContext>
+function buildContextWithMeta(
+  threadId: ThreadId,
+  role: string,
+): Promise<AgentContext & { meta: BuildContextMeta }>
+
+type AgentContext = ModeratorContext & {
+  threadId: ThreadId;
+  role: string;
+  store: Store;
+  workflow: WorkflowPayload;
+  outputFormatInstruction: string;
+  edgePrompt: string;
+  isFirstVisit: boolean;
+};
+
+type BuildContextMeta = {
+  storageRoot: string;
+  store: Store;
+  schemas: AgentStore["schemas"];
+  headHash: CasRef;
+  chain: ChainState;
+};
+```
+
+Requires `UWF_EDGE_PROMPT` in the environment (set by `uwf thread step`).
+
+### Prompt builders
+
+```typescript
+function buildRolePrompt(role: RoleDefinition): string
+function buildOutputFormatInstruction(schema: JSONSchema): string
+function buildContinuationPrompt(
+  ctx: AgentContext,
+  priorOutput: string,
+  instruction: string,
+): string
+```
+
+### Extract pipeline
+
+```typescript
+function resolveExtractModelAlias(config: WorkflowConfig): ModelAlias
+function resolveModel(config: WorkflowConfig, alias: ModelAlias): ResolvedLlmProvider
+function extract(
+  rawOutput: string,
+  outputSchema: CasRef,
+  config: WorkflowConfig,
+): Promise<ExtractResult>
+
+type ResolvedLlmProvider = { baseUrl: string; apiKey: string; model: string };
+type ExtractResult = { value: unknown; hash: CasRef };
+```
+
+### Frontmatter fast-path
+
+```typescript
+function tryFrontmatterFastPath(
+  rawOutput: string,
+  outputSchema: CasRef,
+  store: Store,
+): Promise<FrontmatterFastPathResult | null>
+
+type FrontmatterFastPathResult = { body: string; outputHash: CasRef };
+```
+
+### Session cache
+
+```typescript
+function getCachedSessionId(threadId: ThreadId, role: string): Promise<string | null>
+function setCachedSessionId(
+  threadId: ThreadId,
+  role: string,
+  sessionId: string,
+): Promise<void>
+```
+
+### Config and storage
+
+```typescript
+function getConfigPath(storageRoot: string): string
+function getEnvPath(storageRoot: string): string
+function resolveStorageRoot(): string
+function loadWorkflowConfig(storageRoot: string): Promise<WorkflowConfig>
+```
+
+## Usage
+
+```typescript
+import { createAgent, buildRolePrompt } from "@uncaged/workflow-agent-kit";
+import type { AgentContext, AgentRunResult } from "@uncaged/workflow-agent-kit";
+
+async function run(ctx: AgentContext): Promise<AgentRunResult> {
+  const prompt = buildRolePrompt(ctx.workflow.roles[ctx.role]!);
+  // ... spawn external process, capture output ...
+  return { output: markdown, detailHash: "...", sessionId: "..." };
+}
+
+async function continueSession(
+  sessionId: string,
+  message: string,
+): Promise<AgentRunResult> {
+  // ... continue multi-turn session ...
+  return { output: markdown, detailHash: "...", sessionId };
+}
+
+export const main = createAgent({ name: "my-agent", run, continue: continueSession });
+```
+
+## Internal Structure
+
+```
+src/
+├── index.ts
+├── run.ts                         createAgent entrypoint
+├── context.ts                     Thread chain walk, AgentContext builder
+├── extract.ts                     LLM structured extract fallback
+├── frontmatter.ts                 Frontmatter fast-path validation
+├── build-role-prompt.ts           Role definition → prompt text
+├── build-output-format-instruction.ts
+├── build-continuation-prompt.ts
+├── session-cache.ts               Per-thread/session ID persistence
+├── storage.ts                     CAS store, config, threads index
+├── schemas.ts                     Agent CAS schema registration
+└── types.ts                       AgentContext, AgentOptions, etc.
+```
+
+## Configuration
+
+Reads `config.yaml` and `.env` from the workflow storage root (`~/.uncaged/workflow` by default). See `@uncaged/workflow-protocol` for `WorkflowConfig` shape. Set via `uwf setup`.
@@ -7,6 +7,7 @@ const reviewerStep: StepContext = {
  output: { approved: false, comments: "Missing tests" },
  detail: "2MXBG6PN4A8JR",
  agent: "uwf-hermes",
+  edgePrompt: "Review the developer's work.",
 };

 const developerStep: StepContext = {
@@ -14,6 +15,7 @@ const developerStep: StepContext = {
  output: { filesChanged: ["src/app.ts"], summary: "Initial fix" },
  detail: "1VPBG9SM5E7WK",
  agent: "uwf-hermes",
+  edgePrompt: "Implement the fix.",
 };

 describe("buildContinuationPrompt", () => {
@@ -26,6 +28,7 @@ describe("buildContinuationPrompt", () => {
        output: { plan: "revise approach" },
        detail: "7BQST3VW9F2MA",
        agent: "uwf-hermes",
+        edgePrompt: "Revise the plan.",
      },
    ];

@@ -0,0 +1,247 @@
+import { mkdir, readdir, readFile, rm, stat, writeFile } from "node:fs/promises";
+import { dirname, join } from "node:path";
+import type { ThreadId } from "@uncaged/workflow-protocol";
+import { afterEach, beforeEach, describe, expect, test } from "vitest";
+
+import { getCachedSessionId, getCachePath, setCachedSessionId } from "../src/session-cache.js";
+import { resolveStorageRoot } from "../src/storage.js";
+
+describe("session-cache", () => {
+  let originalStorageRoot: string;
+  let testStorageRoot: string;
+
+  beforeEach(async () => {
+    // Create a temporary test storage root
+    originalStorageRoot = resolveStorageRoot();
+    testStorageRoot = join(originalStorageRoot, "test-cache", `test-${Date.now()}`);
+    await mkdir(testStorageRoot, { recursive: true });
+
+    // Override the storage root for testing
+    process.env.WORKFLOW_STORAGE_ROOT = testStorageRoot;
+  });
+
+  afterEach(async () => {
+    // Clean up test storage root
+    await rm(testStorageRoot, { recursive: true, force: true });
+    delete process.env.WORKFLOW_STORAGE_ROOT;
+  });
+
+  describe("getCachePath", () => {
+    test("returns agent-specific file path", () => {
+      const path = getCachePath("claude-code");
+      expect(path).toMatch(/\/cache\/claude-code-sessions\.json$/);
+    });
+
+    test("returns different paths for different agents", () => {
+      const pathClaudeCode = getCachePath("claude-code");
+      const pathHermes = getCachePath("hermes");
+
+      expect(pathClaudeCode).not.toBe(pathHermes);
+      expect(pathClaudeCode).toMatch(/claude-code-sessions\.json$/);
+      expect(pathHermes).toMatch(/hermes-sessions\.json$/);
+    });
+
+    test("handles agent names with special characters", () => {
+      const path1 = getCachePath("my-agent");
+      const path2 = getCachePath("my_agent");
+
+      expect(path1).toMatch(/my-agent-sessions\.json$/);
+      expect(path2).toMatch(/my_agent-sessions\.json$/);
+    });
+  });
+
+  describe("session isolation", () => {
+    const threadId = "01234567890123456789012345" as ThreadId;
+    const role = "developer";
+
+    test("sessions are isolated per agent", async () => {
+      // Cache different session IDs for each agent
+      await setCachedSessionId("claude-code", threadId, role, "session-cc-001");
+      await setCachedSessionId("hermes", threadId, role, "session-hermes-001");
+
+      // Each agent should retrieve its own session ID
+      const sessionCC = await getCachedSessionId("claude-code", threadId, role);
+      const sessionHermes = await getCachedSessionId("hermes", threadId, role);
+
+      expect(sessionCC).toBe("session-cc-001");
+      expect(sessionHermes).toBe("session-hermes-001");
+    });
+
+    test("updating one agent's cache does not affect another", async () => {
+      // Set initial sessions for both agents
+      await setCachedSessionId("claude-code", threadId, role, "session-cc-001");
+      await setCachedSessionId("hermes", threadId, role, "session-hermes-001");
+
+      // Update claude-code's session
+      await setCachedSessionId("claude-code", threadId, role, "session-cc-002");
+
+      // Hermes's session should remain unchanged
+      const sessionHermes = await getCachedSessionId("hermes", threadId, role);
+      expect(sessionHermes).toBe("session-hermes-001");
+
+      // Claude-code should have the new session
+      const sessionCC = await getCachedSessionId("claude-code", threadId, role);
+      expect(sessionCC).toBe("session-cc-002");
+    });
+
+    test("missing session returns null for specific agent", async () => {
+      const session = await getCachedSessionId("claude-code", threadId, role);
+      expect(session).toBeNull();
+    });
+
+    test("empty session ID is treated as missing", async () => {
+      await setCachedSessionId("claude-code", threadId, role, "");
+
+      const session = await getCachedSessionId("claude-code", threadId, role);
+      expect(session).toBeNull();
+    });
+  });
+
+  describe("file system operations", () => {
+    const threadId = "01234567890123456789012345" as ThreadId;
+    const role = "developer";
+
+    test("cache directory is created if missing", async () => {
+      const cachePath = getCachePath("claude-code");
+      const cacheDir = dirname(cachePath);
+
+      // Ensure cache dir doesn't exist
+      await rm(cacheDir, { recursive: true, force: true });
+
+      // Write a session
+      await setCachedSessionId("claude-code", threadId, role, "session-001");
+
+      // Cache directory should be created
+      const stats = await stat(cacheDir);
+      expect(stats.isDirectory()).toBe(true);
+    });
+
+    test("multiple agents create separate cache files", async () => {
+      // Cache sessions for multiple agents
+      await setCachedSessionId("claude-code", threadId, role, "session-cc-001");
+      await setCachedSessionId("hermes", threadId, role, "session-hermes-001");
+
+      // Separate cache files should exist
+      const pathCC = getCachePath("claude-code");
+      const pathHermes = getCachePath("hermes");
+
+      const contentCC = JSON.parse(await readFile(pathCC, "utf8")) as Record<string, string>;
+      const contentHermes = JSON.parse(await readFile(pathHermes, "utf8")) as Record<
+        string,
+        string
+      >;
+
+      expect(contentCC).toHaveProperty(`${threadId}:${role}`, "session-cc-001");
+      expect(contentHermes).toHaveProperty(`${threadId}:${role}`, "session-hermes-001");
+    });
+
+    test("atomic writes prevent partial reads", async () => {
+      // Write a session
+      await setCachedSessionId("claude-code", threadId, role, "session-001");
+
+      // The final file should exist (no .tmp files left behind)
+      const cachePath = getCachePath("claude-code");
+      const dir = dirname(cachePath);
+      const files = await readdir(dir);
+
+      expect(files).toContain("claude-code-sessions.json");
+      expect(files.every((f) => !f.endsWith(".tmp"))).toBe(true);
+    });
+  });
+
+  describe("legacy migration", () => {
+    const threadId = "01234567890123456789012345" as ThreadId;
+    const role = "developer";
+
+    test("old agent-sessions.json is ignored", async () => {
+      // Create old agent-sessions.json file
+      const oldCachePath = join(resolveStorageRoot(), "cache", "agent-sessions.json");
+      await mkdir(dirname(oldCachePath), { recursive: true });
+      await writeFile(
+        oldCachePath,
+        JSON.stringify({
+          "01234567890123456789012345:developer": "old-session-001",
+        }),
+        "utf8",
+      );
+
+      // Query with the new per-agent cache
+      const session = await getCachedSessionId("claude-code", threadId, role);
+
+      // Should return null (old cache is ignored)
+      expect(session).toBeNull();
+    });
+
+    test("new per-agent cache takes precedence", async () => {
+      // Create both old and new cache files
+      const oldPath = join(resolveStorageRoot(), "cache", "agent-sessions.json");
+      await mkdir(dirname(oldPath), { recursive: true });
+      await writeFile(
+        oldPath,
+        JSON.stringify({
+          [`${threadId}:${role}`]: "old-session",
+        }),
+        "utf8",
+      );
+
+      await setCachedSessionId("claude-code", threadId, role, "new-session");
+
+      // The new per-agent cache value should be returned
+      const session = await getCachedSessionId("claude-code", threadId, role);
+      expect(session).toBe("new-session");
+    });
+  });
+
+  describe("error handling", () => {
+    const threadId = "01234567890123456789012345" as ThreadId;
+    const role = "developer";
+
+    test("invalid JSON in cache file returns empty cache", async () => {
+      // Create a corrupted cache file
+      const cachePath = getCachePath("claude-code");
+      await mkdir(dirname(cachePath), { recursive: true });
+      await writeFile(cachePath, "{ invalid json }", "utf8");
+
+      // Should return null (treating corrupted cache as empty)
+      const session = await getCachedSessionId("claude-code", threadId, role);
+      expect(session).toBeNull();
+    });
+
+    test("non-object JSON in cache file returns empty cache", async () => {
+      // Create a cache file with non-object JSON
+      const cachePath = getCachePath("claude-code");
+      await mkdir(dirname(cachePath), { recursive: true });
+      await writeFile(cachePath, JSON.stringify(["not", "an", "object"]), "utf8");
+
+      // Should return null
+      const session = await getCachedSessionId("claude-code", threadId, role);
+      expect(session).toBeNull();
+    });
+
+    test("cache entries with non-string values are ignored", async () => {
+      // Create a cache file with mixed types
+      const cachePath = getCachePath("claude-code");
+      const cacheData = {
+        "thread1:role1": "valid-session",
+        "thread2:role2": 12345, // number
+        "thread3:role3": null, // null
+        "thread4:role4": "", // empty string
+      };
+      await mkdir(dirname(cachePath), { recursive: true });
+      await writeFile(cachePath, JSON.stringify(cacheData), "utf8");
+
+      // Valid string entries should be returned
+      const session1 = await getCachedSessionId("claude-code", "thread1" as ThreadId, "role1");
+      expect(session1).toBe("valid-session");
+
+      // Invalid entries should return null
+      const session2 = await getCachedSessionId("claude-code", "thread2" as ThreadId, "role2");
+      const session3 = await getCachedSessionId("claude-code", "thread3" as ThreadId, "role3");
+      const session4 = await getCachedSessionId("claude-code", "thread4" as ThreadId, "role4");
+
+      expect(session2).toBeNull();
+      expect(session3).toBeNull();
+      expect(session4).toBeNull(); // empty string is treated as missing
+    });
+  });
+});
@@ -21,14 +21,6 @@ function fail(message: string): never {
  throw new Error(message);
 }

-function readEdgePrompt(): string {
-  const value = process.env.UWF_EDGE_PROMPT;
-  if (value === undefined || value === "") {
-    fail("UWF_EDGE_PROMPT environment variable is required");
-  }
-  return value;
-}
-
 function walkChain(store: Store, schemas: AgentStore["schemas"], headHash: CasRef): ChainState {
  const headNode = store.get(headHash);
  if (headNode === null) {
@@ -102,6 +94,7 @@ async function buildHistory(
      output: expandOutput(store, step.output),
      detail: step.detail,
      agent: step.agent,
+      edgePrompt: step.edgePrompt ?? "",
    });
  }
  return history;
@@ -122,7 +115,11 @@ async function loadWorkflow(store: Store, schemas: AgentStore["schemas"], workfl
 * Build agent execution context from thread head in threads.yaml.
 * Walks the CAS chain from head to StartNode and expands step outputs.
 */
-export async function buildContext(threadId: ThreadId, role: string): Promise<AgentContext> {
+export async function buildContext(
+  threadId: ThreadId,
+  role: string,
+  edgePrompt: string,
+): Promise<AgentContext> {
  const storageRoot = resolveStorageRoot();
  const agentStore = await createAgentStore(storageRoot);
  const { store, schemas } = agentStore;
@@ -141,7 +138,6 @@ export async function buildContext(threadId: ThreadId, role: string): Promise<Ag
  }

  const steps = await buildHistory(store, chain.stepsNewestFirst);
-  const edgePrompt = readEdgePrompt();
  const isFirstVisit = !steps.some((s) => s.role === role);

  return {
@@ -171,6 +167,7 @@ export type BuildContextMeta = {
 export async function buildContextWithMeta(
  threadId: ThreadId,
  role: string,
+  edgePrompt: string,
 ): Promise<AgentContext & { meta: BuildContextMeta }> {
  const storageRoot = resolveStorageRoot();
  const agentStore = await createAgentStore(storageRoot);
@@ -190,7 +187,6 @@ export async function buildContextWithMeta(
  }

  const steps = await buildHistory(store, chain.stepsNewestFirst);
-  const edgePrompt = readEdgePrompt();
  const isFirstVisit = !steps.some((s) => s.role === role);

  return {
@@ -12,6 +12,7 @@ export {
 export type { FrontmatterFastPathResult } from "./frontmatter.js";
 export { tryFrontmatterFastPath } from "./frontmatter.js";
 export { createAgent } from "./run.js";
+export { getCachedSessionId, getCachePath, setCachedSessionId } from "./session-cache.js";
 export { getConfigPath, getEnvPath, loadWorkflowConfig, resolveStorageRoot } from "./storage.js";
 export type {
  AgentContext,
@@ -22,16 +22,24 @@ function agentLabel(name: string): string {
  return `uwf-${name}`;
 }

-function parseArgv(argv: string[]): { threadId: ThreadId; role: string } {
-  const threadId = argv[2];
-  const role = argv[3];
-  if (threadId === undefined || threadId === "") {
-    fail("usage: <agent-cli> <thread-id> <role>");
+const USAGE = "usage: <agent-cli> --thread <id> --role <role> --prompt <text>";
+
+function getNamedArg(argv: string[], name: string): string {
+  const idx = argv.indexOf(name);
+  if (idx === -1 || idx + 1 >= argv.length) {
+    return "";
  }
-  if (role === undefined || role === "") {
-    fail("usage: <agent-cli> <thread-id> <role>");
-  }
-  return { threadId: threadId as ThreadId, role };
+  return argv[idx + 1];
+}
+
+function parseArgv(argv: string[]): { threadId: ThreadId; role: string; prompt: string } {
+  const threadId = getNamedArg(argv, "--thread");
+  const role = getNamedArg(argv, "--role");
+  const prompt = getNamedArg(argv, "--prompt");
+  if (threadId === "") fail(USAGE);
+  if (role === "") fail(USAGE);
+  if (prompt === "") fail(USAGE);
+  return { threadId: threadId as ThreadId, role, prompt };
 }

 function runWithMessage<T>(label: string, fn: () => Promise<T>): Promise<T> {
@@ -50,6 +58,7 @@ async function writeStepNode(options: {
  outputHash: CasRef;
  detailHash: CasRef;
  agentName: string;
+  edgePrompt: string;
 }): Promise<CasRef> {
  const payload: StepNodePayload = {
    start: options.startHash,
@@ -58,6 +67,7 @@ async function writeStepNode(options: {
    output: options.outputHash,
    detail: options.detailHash,
    agent: options.agentName,
+    edgePrompt: options.edgePrompt,
  };
  const hash = await options.store.put(options.schemas.stepNode, payload);
  const node = options.store.get(hash);
@@ -95,16 +105,17 @@ async function persistStep(options: {
    outputHash: options.outputHash,
    detailHash: options.detailHash,
    agentName: options.agentName,
+    edgePrompt: options.ctx.edgePrompt,
  });
 }

 export function createAgent(options: AgentOptions): () => Promise<void> {
  return async function main(): Promise<void> {
-    const { threadId, role } = parseArgv(process.argv);
+    const { threadId, role, prompt } = parseArgv(process.argv);
    const storageRoot = resolveStorageRoot();
    loadDotenv({ path: getEnvPath(storageRoot) });

-    const ctx = await runWithMessage("context", () => buildContextWithMeta(threadId, role));
+    const ctx = await runWithMessage("context", () => buildContextWithMeta(threadId, role, prompt));

    const roleDef = ctx.workflow.roles[role];
    if (roleDef === undefined) {
@@ -118,6 +129,11 @@ export function createAgent(options: AgentOptions): () => Promise<void> {

    let agentResult = await runWithMessage("agent run failed", () => options.run(ctx));

+    // Preserve the primary detail from the first run — it contains the full
+    // tool-call turn history.  Continuation retries only fix frontmatter
+    // formatting and their 1-turn detail is not meaningful.
+    const primaryDetailHash = agentResult.detailHash;
+
    // Try to extract frontmatter; retry via continue if it fails
    let outputHash = await tryExtractOutput(agentResult.output, roleDef.frontmatter, ctx);

@@ -144,7 +160,7 @@ export function createAgent(options: AgentOptions): () => Promise<void> {
    const stepHash = await persistStep({
      ctx,
      outputHash,
-      detailHash: agentResult.detailHash,
+      detailHash: primaryDetailHash,
      agentName: agentLabel(options.name),
    });

@@ -0,0 +1,84 @@
+import { randomBytes } from "node:crypto";
+import { mkdir, readFile, rename, writeFile } from "node:fs/promises";
+import { dirname, join } from "node:path";
+
+import type { ThreadId } from "@uncaged/workflow-protocol";
+
+import { resolveStorageRoot } from "./storage.js";
+
+type SessionCache = Record<string, string>;
+
+export function getCachePath(agentName: string): string {
+  return join(resolveStorageRoot(), "cache", `${agentName}-sessions.json`);
+}
+
+function cacheKey(threadId: ThreadId, role: string): string {
+  return `${threadId}:${role}`;
+}
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+async function readCache(agentName: string): Promise<SessionCache> {
+  const path = getCachePath(agentName);
+  try {
+    const text = await readFile(path, "utf8");
+    const raw = JSON.parse(text) as unknown;
+    if (!isRecord(raw)) {
+      return {};
+    }
+    const cache: SessionCache = {};
+    for (const [key, value] of Object.entries(raw)) {
+      if (typeof value === "string" && value !== "") {
+        cache[key] = value;
+      }
+    }
+    return cache;
+  } catch (e) {
+    const err = e as NodeJS.ErrnoException;
+    if (err.code === "ENOENT") {
+      return {};
+    }
+    // Treat JSON parse errors as empty cache
+    if (err.name === "SyntaxError") {
+      return {};
+    }
+    throw e;
+  }
+}
+
+async function writeCache(agentName: string, cache: SessionCache): Promise<void> {
+  const path = getCachePath(agentName);
+  const dir = dirname(path);
+  await mkdir(dir, { recursive: true });
+  // Atomic write: write to temp file then rename to avoid partial reads on concurrent access.
+  // NOTE: Current workflow execution is serial (execFileSync), so true concurrency doesn't occur.
+  // This is a safety net for future parallel execution.
+  const tmpPath = join(dir, `.${agentName}-sessions.${randomBytes(4).toString("hex")}.tmp`);
+  await writeFile(tmpPath, `${JSON.stringify(cache, null, 2)}\n`, "utf8");
+  await rename(tmpPath, path);
+}
+
+/** Read the cached session ID for a thread+role pair. */
+export async function getCachedSessionId(
+  agentName: string,
+  threadId: ThreadId,
+  role: string,
+): Promise<string | null> {
+  const cache = await readCache(agentName);
+  const sessionId = cache[cacheKey(threadId, role)];
+  return sessionId ?? null;
+}
+
+/** Write the session ID for a thread+role pair into the cache. */
+export async function setCachedSessionId(
+  agentName: string,
+  threadId: ThreadId,
+  role: string,
+  sessionId: string,
+): Promise<void> {
+  const cache = await readCache(agentName);
+  cache[cacheKey(threadId, role)] = sessionId;
+  await writeCache(agentName, cache);
+}
@@ -13,7 +13,7 @@ export type AgentContext = ModeratorContext & {
   */
  outputFormatInstruction: string;
  /**
-   * Edge prompt from the graph transition that led to this role (UWF_EDGE_PROMPT).
+   * Edge prompt from the graph transition that led to this role (--prompt CLI arg).
   * Always the real moderator instruction for this step.
   */
  edgePrompt: string;
@@ -0,0 +1,84 @@
+# @uncaged/workflow-dashboard
+
+Web graph editor for visualizing and editing workflow YAML definitions.
+
+## Overview
+
+A private alpha web app (not part of the runtime engine stack). Provides a React + `@xyflow/react` canvas for editing workflow roles, conditions, and graph transitions. Uses `@uncaged/workflow-protocol` types for validation and YAML round-tripping.
+
+Planned integration: local `uwf connect` over WebSocket to sync YAML between CLI and the browser editor. The REST API and Elysia backend are currently stubs for development.
+
+**Dependencies:** `@uncaged/workflow-protocol`, `@xyflow/react`, React 19, react-router v7, Vite 8, Tailwind CSS v4, Elysia
+
+## Installation
+
+Monorepo-only ( `"private": true` ). Not published to npm.
+
+```bash
+cd packages/workflow-dashboard
+bun install --no-cache
+```
+
+## CLI Usage
+
+Start the Vite dev server (port 3000):
+
+```bash
+cd packages/workflow-dashboard
+bun run dev
+```
+
+Build for production:
+
+```bash
+bun run build
+```
+
+Open `http://localhost:3000` in a browser.
+
+## Internal Structure
+
+```
+workflow-dashboard/
+├── server.ts                 Vite dev server entry (port 3000)
+├── vite.config.ts            Vite + React + Tailwind + Elysia plugin
+├── vite-dev.ts               Custom Vite plugin
+├── index.html
+├── components.json           shadcn configuration
+├── server/
+│   ├── api.ts                Elysia REST API (health + workflow CRUD stub)
+│   └── workflow.ts           Workflow file read/write + format conversion
+└── src/
+    ├── main.tsx              React DOM entry
+    ├── app.tsx               Root layout
+    ├── router.tsx            Hash-mode routes
+    ├── index.css
+    ├── lib/utils.ts          Tailwind cn() helper
+    ├── components/ui/        shadcn components (button, card, dialog, input, …)
+    ├── pages/
+    │   ├── home.tsx          Workflow list
+    │   ├── detail.tsx        Workflow detail view
+    │   └── editor.tsx        Full editor page
+    └── editor/               Core graph editor
+        ├── flow.tsx          FlowEditor component
+        ├── context.tsx       State (useSyncExternalStore + Immer)
+        ├── injection.ts      DI container
+        ├── type.ts             Internal editor types
+        ├── model/              Node/edge state model
+        ├── nodes/              Start, role, end node components
+        ├── edges/              Conditional edge rendering
+        ├── panel/              Toolbar, add/edit panels
+        ├── trans/              YAML ↔ graph conversion (trans-in, trans-out, validate)
+        ├── layout/             Auto-layout
+        └── utils/              Event helpers, click-outside hook
+```
+
+## Configuration
+
+| Setting | Default | Notes |
+|---------|---------|-------|
+| Dev server port | `3000` | Set in `server.ts` |
+| Workflow storage (dev) | `tmp/workflow/` | YAML files during development |
+| Path alias | `@/` → `src/` | Configured in `vite.config.ts` |
+
+No library API — this package is an application, not importable as a module.
@@ -6,8 +6,8 @@
    <title>Workflow UI</title>
    <link rel="stylesheet" href="./src/index.css" />
    <script>
-      (function () {
-        var t = localStorage.getItem("theme");
+      (() => {
+        const t = localStorage.getItem("theme");
        if (t === "dark" || (!t && matchMedia("(prefers-color-scheme: dark)").matches)) {
          document.documentElement.classList.add("dark");
        }
@@ -31,8 +31,10 @@
    "@types/react": "^19.2.14",
    "@types/react-dom": "^19.2.3",
    "@vitejs/plugin-react": "^6.0.2",
+    "@vitest/ui": "^4.1.7",
    "tailwindcss": "^4.2.4",
    "typescript": "^5.8.3",
-    "vite": "^8.0.13"
+    "vite": "^8.0.13",
+    "vitest": "^4.1.7"
  }
 }
@@ -7,6 +7,3 @@ const server = await createServer({
 });

 await server.listen();
-
-// biome-ignore lint/nursery/noConsole: CLI user-facing output
-console.log(`Workflow UI running at http://localhost:${PORT}`);
@@ -1,11 +1,11 @@
 import { Elysia, t } from "elysia";
 import type { WorkFlowSteps } from "../shared/types.ts";
 import {
-  listWorkflows,
-  getWorkflow,
  createWorkflow,
-  saveWorkflow,
  deleteWorkflow,
+  getWorkflow,
+  listWorkflows,
+  saveWorkflow,
 } from "./workflow.ts";

 export function createApi() {
@@ -1,11 +1,7 @@
-import { readdir, readFile, writeFile, unlink, mkdir } from "node:fs/promises";
+import { mkdir, readdir, readFile, unlink, writeFile } from "node:fs/promises";
 import { join } from "node:path";
+import type { RoleDefinition, Transition, WorkflowPayload } from "@uncaged/workflow-protocol";
 import YAML from "yaml";
-import type {
-  WorkflowPayload,
-  RoleDefinition,
-  Transition,
-} from "@uncaged/workflow-protocol";
 import type { WorkFlowSteps, WorkFlowTransition, WorkflowSummary } from "../shared/types.ts";

 const WORKFLOW_DIR = join(import.meta.dirname, "..", "tmp", "workflow");
@@ -67,7 +63,7 @@ function stepsToPayload(name: string, description: string, steps: WorkFlowSteps)
      let condName: string | null = null;
      if (t.condition) {
        if (expressionToName.has(t.condition)) {
-          condName = expressionToName.get(t.condition)!;
+          condName = expressionToName.get(t.condition) ?? null;
        } else {
          condName = `cond${condIdx++}`;
          expressionToName.set(t.condition, condName);
@@ -90,7 +86,7 @@ function stepsToPayload(name: string, description: string, steps: WorkFlowSteps)

  if (steps.length > 0) {
    const firstRole = steps[0].role.name;
-    graph["$START"] = [
+    graph.$START = [
      {
        role: firstRole,
        condition: null,
@@ -1,7 +1,7 @@
-import { Button as ButtonPrimitive } from "@base-ui/react/button"
-import { cva, type VariantProps } from "class-variance-authority"
+import { Button as ButtonPrimitive } from "@base-ui/react/button";
+import { cva, type VariantProps } from "class-variance-authority";

-import { cn } from "@/lib/utils"
+import { cn } from "@/lib/utils";

 const buttonVariants = cva(
  "group/button inline-flex shrink-0 items-center justify-center rounded-lg border border-transparent bg-clip-padding text-sm font-medium whitespace-nowrap transition-all outline-none select-none focus-visible:border-ring focus-visible:ring-3 focus-visible:ring-ring/50 active:not-aria-[haspopup]:translate-y-px disabled:pointer-events-none disabled:opacity-50 aria-invalid:border-destructive aria-invalid:ring-3 aria-invalid:ring-destructive/20 dark:aria-invalid:border-destructive/50 dark:aria-invalid:ring-destructive/40 [&_svg]:pointer-events-none [&_svg]:shrink-0 [&_svg:not([class*='size-'])]:size-4",
@@ -37,8 +37,8 @@ const buttonVariants = cva(
      variant: "default",
      size: "default",
    },
-  }
-)
+  },
+);

 function Button({
  className,
@@ -52,7 +52,7 @@ function Button({
      className={cn(buttonVariants({ variant, size, className }))}
      {...props}
    />
-  )
+  );
 }

-export { Button, buttonVariants }
+export { Button, buttonVariants };
@@ -1,6 +1,6 @@
-import * as React from "react"
+import type * as React from "react";

-import { cn } from "@/lib/utils"
+import { cn } from "@/lib/utils";

 function Card({
  className,
@@ -13,11 +13,11 @@ function Card({
      data-size={size}
      className={cn(
        "group/card flex flex-col gap-4 overflow-hidden rounded-xl bg-card py-4 text-sm text-card-foreground ring-1 ring-foreground/10 has-data-[slot=card-footer]:pb-0 has-[>img:first-child]:pt-0 data-[size=sm]:gap-3 data-[size=sm]:py-3 data-[size=sm]:has-data-[slot=card-footer]:pb-0 *:[img:first-child]:rounded-t-xl *:[img:last-child]:rounded-b-xl",
-        className
+        className,
      )}
      {...props}
    />
-  )
+  );
 }

 function CardHeader({ className, ...props }: React.ComponentProps<"div">) {
@@ -26,11 +26,11 @@ function CardHeader({ className, ...props }: React.ComponentProps<"div">) {
      data-slot="card-header"
      className={cn(
        "group/card-header @container/card-header grid auto-rows-min items-start gap-1 rounded-t-xl px-4 group-data-[size=sm]/card:px-3 has-data-[slot=card-action]:grid-cols-[1fr_auto] has-data-[slot=card-description]:grid-rows-[auto_auto] [.border-b]:pb-4 group-data-[size=sm]/card:[.border-b]:pb-3",
-        className
+        className,
      )}
      {...props}
    />
-  )
+  );
 }

 function CardTitle({ className, ...props }: React.ComponentProps<"div">) {
@@ -39,11 +39,11 @@ function CardTitle({ className, ...props }: React.ComponentProps<"div">) {
      data-slot="card-title"
      className={cn(
        "font-heading text-base leading-snug font-medium group-data-[size=sm]/card:text-sm",
-        className
+        className,
      )}
      {...props}
    />
-  )
+  );
 }

 function CardDescription({ className, ...props }: React.ComponentProps<"div">) {
@@ -53,20 +53,17 @@ function CardDescription({ className, ...props }: React.ComponentProps<"div">) {
      className={cn("text-sm text-muted-foreground", className)}
      {...props}
    />
-  )
+  );
 }

 function CardAction({ className, ...props }: React.ComponentProps<"div">) {
  return (
    <div
      data-slot="card-action"
-      className={cn(
-        "col-start-2 row-span-2 row-start-1 self-start justify-self-end",
-        className
-      )}
+      className={cn("col-start-2 row-span-2 row-start-1 self-start justify-self-end", className)}
      {...props}
    />
-  )
+  );
 }

 function CardContent({ className, ...props }: React.ComponentProps<"div">) {
@@ -76,7 +73,7 @@ function CardContent({ className, ...props }: React.ComponentProps<"div">) {
      className={cn("px-4 group-data-[size=sm]/card:px-3", className)}
      {...props}
    />
-  )
+  );
 }

 function CardFooter({ className, ...props }: React.ComponentProps<"div">) {
@@ -85,19 +82,11 @@ function CardFooter({ className, ...props }: React.ComponentProps<"div">) {
      data-slot="card-footer"
      className={cn(
        "flex items-center rounded-b-xl border-t bg-muted/50 p-4 group-data-[size=sm]/card:p-3",
-        className
+        className,
      )}
      {...props}
    />
-  )
+  );
 }

-export {
-  Card,
-  CardHeader,
-  CardFooter,
-  CardTitle,
-  CardAction,
-  CardDescription,
-  CardContent,
-}
+export { Card, CardAction, CardContent, CardDescription, CardFooter, CardHeader, CardTitle };
@@ -1,40 +1,36 @@
-import * as React from "react"
-import { Dialog as DialogPrimitive } from "@base-ui/react/dialog"
-
-import { cn } from "@/lib/utils"
-import { Button } from "@/components/ui/button"
-import { XIcon } from "lucide-react"
+import { Dialog as DialogPrimitive } from "@base-ui/react/dialog";
+import { XIcon } from "lucide-react";
+import type * as React from "react";
+import { Button } from "@/components/ui/button";
+import { cn } from "@/lib/utils";

 function Dialog({ ...props }: DialogPrimitive.Root.Props) {
-  return <DialogPrimitive.Root data-slot="dialog" {...props} />
+  return <DialogPrimitive.Root data-slot="dialog" {...props} />;
 }

 function DialogTrigger({ ...props }: DialogPrimitive.Trigger.Props) {
-  return <DialogPrimitive.Trigger data-slot="dialog-trigger" {...props} />
+  return <DialogPrimitive.Trigger data-slot="dialog-trigger" {...props} />;
 }

 function DialogPortal({ ...props }: DialogPrimitive.Portal.Props) {
-  return <DialogPrimitive.Portal data-slot="dialog-portal" {...props} />
+  return <DialogPrimitive.Portal data-slot="dialog-portal" {...props} />;
 }

 function DialogClose({ ...props }: DialogPrimitive.Close.Props) {
-  return <DialogPrimitive.Close data-slot="dialog-close" {...props} />
+  return <DialogPrimitive.Close data-slot="dialog-close" {...props} />;
 }

-function DialogOverlay({
-  className,
-  ...props
-}: DialogPrimitive.Backdrop.Props) {
+function DialogOverlay({ className, ...props }: DialogPrimitive.Backdrop.Props) {
  return (
    <DialogPrimitive.Backdrop
      data-slot="dialog-overlay"
      className={cn(
        "fixed inset-0 isolate z-50 bg-black/10 duration-100 supports-backdrop-filter:backdrop-blur-xs data-open:animate-in data-open:fade-in-0 data-closed:animate-out data-closed:fade-out-0",
-        className
+        className,
      )}
      {...props}
    />
-  )
+  );
 }

 function DialogContent({
@@ -43,7 +39,7 @@ function DialogContent({
  showCloseButton = true,
  ...props
 }: DialogPrimitive.Popup.Props & {
-  showCloseButton?: boolean
+  showCloseButton?: boolean;
 }) {
  return (
    <DialogPortal>
@@ -52,7 +48,7 @@ function DialogContent({
        data-slot="dialog-content"
        className={cn(
          "fixed top-1/2 left-1/2 z-50 grid w-full max-w-[calc(100%-2rem)] -translate-x-1/2 -translate-y-1/2 gap-4 rounded-xl bg-popover p-4 text-sm text-popover-foreground ring-1 ring-foreground/10 duration-100 outline-none sm:max-w-sm data-open:animate-in data-open:fade-in-0 data-open:zoom-in-95 data-closed:animate-out data-closed:fade-out-0 data-closed:zoom-out-95",
-          className
+          className,
        )}
        {...props}
      >
@@ -60,32 +56,21 @@ function DialogContent({
        {showCloseButton && (
          <DialogPrimitive.Close
            data-slot="dialog-close"
-            render={
-              <Button
-                variant="ghost"
-                className="absolute top-2 right-2"
-                size="icon-sm"
-              />
-            }
+            render={<Button variant="ghost" className="absolute top-2 right-2" size="icon-sm" />}
          >
-            <XIcon
-            />
+            <XIcon />
            <span className="sr-only">Close</span>
          </DialogPrimitive.Close>
        )}
      </DialogPrimitive.Popup>
    </DialogPortal>
-  )
+  );
 }

 function DialogHeader({ className, ...props }: React.ComponentProps<"div">) {
  return (
-    <div
-      data-slot="dialog-header"
-      className={cn("flex flex-col gap-2", className)}
-      {...props}
-    />
-  )
+    <div data-slot="dialog-header" className={cn("flex flex-col gap-2", className)} {...props} />
+  );
 }

 function DialogFooter({
@@ -94,54 +79,46 @@ function DialogFooter({
  children,
  ...props
 }: React.ComponentProps<"div"> & {
-  showCloseButton?: boolean
+  showCloseButton?: boolean;
 }) {
  return (
    <div
      data-slot="dialog-footer"
      className={cn(
        "-mx-4 -mb-4 flex flex-col-reverse gap-2 rounded-b-xl border-t bg-muted/50 p-4 sm:flex-row sm:justify-end",
-        className
+        className,
      )}
      {...props}
    >
      {children}
      {showCloseButton && (
-        <DialogPrimitive.Close render={<Button variant="outline" />}>
-          Close
-        </DialogPrimitive.Close>
+        <DialogPrimitive.Close render={<Button variant="outline" />}>Close</DialogPrimitive.Close>
      )}
    </div>
-  )
+  );
 }

 function DialogTitle({ className, ...props }: DialogPrimitive.Title.Props) {
  return (
    <DialogPrimitive.Title
      data-slot="dialog-title"
-      className={cn(
-        "font-heading text-base leading-none font-medium",
-        className
-      )}
+      className={cn("font-heading text-base leading-none font-medium", className)}
      {...props}
    />
-  )
+  );
 }

-function DialogDescription({
-  className,
-  ...props
-}: DialogPrimitive.Description.Props) {
+function DialogDescription({ className, ...props }: DialogPrimitive.Description.Props) {
  return (
    <DialogPrimitive.Description
      data-slot="dialog-description"
      className={cn(
        "text-sm text-muted-foreground *:[a]:underline *:[a]:underline-offset-3 *:[a]:hover:text-foreground",
-        className
+        className,
      )}
      {...props}
    />
-  )
+  );
 }

 export {
@@ -155,4 +132,4 @@ export {
  DialogPortal,
  DialogTitle,
  DialogTrigger,
-}
+};
@@ -1,7 +1,7 @@
-import * as React from "react"
-import { Input as InputPrimitive } from "@base-ui/react/input"
+import { Input as InputPrimitive } from "@base-ui/react/input";
+import type * as React from "react";

-import { cn } from "@/lib/utils"
+import { cn } from "@/lib/utils";

 function Input({ className, type, ...props }: React.ComponentProps<"input">) {
  return (
@@ -10,11 +10,11 @@ function Input({ className, type, ...props }: React.ComponentProps<"input">) {
      data-slot="input"
      className={cn(
        "h-8 w-full min-w-0 rounded-lg border border-input bg-transparent px-2.5 py-1 text-base transition-colors outline-none file:inline-flex file:h-6 file:border-0 file:bg-transparent file:text-sm file:font-medium file:text-foreground placeholder:text-muted-foreground focus-visible:border-ring focus-visible:ring-3 focus-visible:ring-ring/50 disabled:pointer-events-none disabled:cursor-not-allowed disabled:bg-input/50 disabled:opacity-50 aria-invalid:border-destructive aria-invalid:ring-3 aria-invalid:ring-destructive/20 md:text-sm dark:bg-input/30 dark:disabled:bg-input/80 dark:aria-invalid:border-destructive/50 dark:aria-invalid:ring-destructive/40",
-        className
+        className,
      )}
      {...props}
    />
-  )
+  );
 }

-export { Input }
+export { Input };
@@ -1,18 +1,19 @@
-import * as React from "react"
+import type * as React from "react";

-import { cn } from "@/lib/utils"
+import { cn } from "@/lib/utils";

 function Label({ className, ...props }: React.ComponentProps<"label">) {
  return (
+    // biome-ignore lint/a11y/noLabelWithoutControl: generic Label component; control association handled by consumer
    <label
      data-slot="label"
      className={cn(
        "flex items-center gap-2 text-sm leading-none font-medium select-none group-data-[disabled=true]:pointer-events-none group-data-[disabled=true]:opacity-50 peer-disabled:cursor-not-allowed peer-disabled:opacity-50",
-        className
+        className,
      )}
      {...props}
    />
-  )
+  );
 }

-export { Label }
+export { Label };
@@ -1,25 +1,21 @@
-"use client"
+"use client";

-import { Separator as SeparatorPrimitive } from "@base-ui/react/separator"
+import { Separator as SeparatorPrimitive } from "@base-ui/react/separator";

-import { cn } from "@/lib/utils"
+import { cn } from "@/lib/utils";

-function Separator({
-  className,
-  orientation = "horizontal",
-  ...props
-}: SeparatorPrimitive.Props) {
+function Separator({ className, orientation = "horizontal", ...props }: SeparatorPrimitive.Props) {
  return (
    <SeparatorPrimitive
      data-slot="separator"
      orientation={orientation}
      className={cn(
        "shrink-0 bg-border data-horizontal:h-px data-horizontal:w-full data-vertical:w-px data-vertical:self-stretch",
-        className
+        className,
      )}
      {...props}
    />
-  )
+  );
 }

-export { Separator }
+export { Separator };
@@ -1,6 +1,6 @@
-import * as React from "react"
+import type * as React from "react";

-import { cn } from "@/lib/utils"
+import { cn } from "@/lib/utils";

 function Textarea({ className, ...props }: React.ComponentProps<"textarea">) {
  return (
@@ -8,11 +8,11 @@ function Textarea({ className, ...props }: React.ComponentProps<"textarea">) {
      data-slot="textarea"
      className={cn(
        "flex field-sizing-content min-h-16 w-full rounded-lg border border-input bg-transparent px-2.5 py-2 text-base transition-colors outline-none placeholder:text-muted-foreground focus-visible:border-ring focus-visible:ring-3 focus-visible:ring-ring/50 disabled:cursor-not-allowed disabled:bg-input/50 disabled:opacity-50 aria-invalid:border-destructive aria-invalid:ring-3 aria-invalid:ring-destructive/20 md:text-sm dark:bg-input/30 dark:disabled:bg-input/80 dark:aria-invalid:border-destructive/50 dark:aria-invalid:ring-destructive/40",
-        className
+        className,
      )}
      {...props}
    />
-  )
+  );
 }

-export { Textarea }
+export { Textarea };
@@ -1,12 +1,12 @@
-import { createContext, useMemo, useSyncExternalStore, useContext, useLayoutEffect } from 'react';
-import type { FC, PropsWithChildren } from 'react';
-import { useReactFlow, ReactFlowInstance } from '@xyflow/react';
-import type { AnyWorkNode } from './type';
+import { type ReactFlowInstance, useReactFlow } from "@xyflow/react";
+import type { FC, PropsWithChildren } from "react";
+import { createContext, useContext, useLayoutEffect, useMemo, useSyncExternalStore } from "react";
+import type { AnyWorkNode } from "./type";

 type Reduce<T> = (data: T) => T;
 type Setter<T> = (ch: Reduce<T> | T) => void;

-interface State<T, A>  {
+interface State<T, A> {
  readonly get: () => T;
  readonly set: Setter<T>;
  readonly use: () => T;
@@ -15,6 +15,7 @@ interface State<T, A>  {
  readonly onlyView: boolean;
 }
 type Use = <T, A>(sub: SubModel<T, A>) => [T, A];
+// biome-ignore lint/suspicious/noExplicitAny: UseV intentionally erases the action type
 type UseV = <T>(sub: SubModel<T, any>) => T;
 type Create<T, A> = (set: Setter<T>, get: () => T, model: Model) => A;

@@ -24,10 +25,12 @@ export function generate<T>(val: T) {
  const listener = new Set<VoidFunction>();
  const get = () => val;
  function set(ch: T | ((prev: T) => T)) {
-    const next = (typeof ch === 'function') ? (ch as (prev: T) => T)(val) : ch;
+    const next = typeof ch === "function" ? (ch as (prev: T) => T)(val) : ch;
    if (Object.is(val, next)) return;
    val = next;
-    listener.forEach(call => call());
+    for (const call of listener) {
+      call();
+    }
  }
  const listen = (call: VoidFunction) => {
    listener.add(call);
@@ -38,21 +41,26 @@ export function generate<T>(val: T) {
 }

 class SubModel<T, A> {
-  constructor(
-    public readonly name: string,
-    private make: () => T,
-    private create: Create<T, A>,
-    private onlyView = false,
-  ) {}
+  public readonly name: string;
+  private readonly make: () => T;
+  private readonly create: Create<T, A>;
+  private readonly onlyView: boolean;
+
+  constructor(name: string, _make: () => T, _create: Create<T, A>, _onlyView = false) {
+    this.name = name;
+    this.make = _make;
+    this.create = _create;
+    this.onlyView = _onlyView;
+  }

  public gen(model: Model): State<T, A> {
-    const { make, create, onlyView } = this;
-    const { get, set, use, listen } = generate(make());
-    const actions = create(set, get, model);
-    return { get, set, use, listen, actions, onlyView };
+    const { get, set, use, listen } = generate(this.make());
+    const actions = this.create(set, get, model);
+    return { get, set, use, listen, actions, onlyView: this.onlyView };
  }

  use(): [T, A] {
+    // biome-ignore lint/correctness/useHookAtTopLevel: use() is called as a hook by consumers
    const { query } = useContext(Context);
    const { use, actions } = query(this);
    return [use(), actions];
@@ -67,20 +75,27 @@ class SubModel<T, A> {
  }
 }

+// biome-ignore lint/suspicious/noExplicitAny: snapshot data is heterogeneous
 type Snapshot = [name: string, data: any];
 class Model {
  private ustack: Snapshot[][] = [];
  private rstack: Snapshot[][] = [];
  private transaction = 0;
+  // biome-ignore lint/suspicious/noExplicitAny: backup stores heterogeneous state values
  private backup = new Map<string, any>();
  public flow = {} as ReactFlowInstance<AnyWorkNode>;
  private stackListeners = new Set<() => void>();
  public readonly stackState: readonly [boolean, boolean] = [false, false];

-  constructor(
-    private readonly store: Map<string, State<any, any>>,
-    public readonly use: Use,
-  ) {}
+  // biome-ignore lint/suspicious/noExplicitAny: store holds heterogeneous state types
+  private readonly store: Map<string, State<any, any>>;
+  public readonly use: Use;
+
+  // biome-ignore lint/suspicious/noExplicitAny: store holds heterogeneous state types
+  constructor(store: Map<string, State<any, any>>, use: Use) {
+    this.store = store;
+    this.use = use;
+  }

  public reset() {
    this.ustack = [];
@@ -93,12 +108,14 @@ class Model {
  public readonly listenStackState = (cb: () => void) => {
    this.stackListeners.add(cb);
    return () => this.stackListeners.delete(cb);
-  }
+  };

  private triggerStackState() {
    // @ts-expect-error
    this.stackState = [this.canUndo(), this.canRedo()];
-    this.stackListeners.forEach(call => call());
+    for (const call of this.stackListeners) {
+      call();
+    }
  }

  private getStackState = () => this.stackState;
@@ -108,13 +125,11 @@ class Model {
  }

  public log() {
-    console.log('undo stack:', this.ustack);
-    console.log('redo stack:', this.rstack);
+    // biome-ignore lint/suspicious/noExplicitAny: debug log accumulates heterogeneous values
    const snapshots: Record<string, any> = {};
-    this.store.forEach((state, name) => {
+    for (const [name, state] of this.store) {
      snapshots[name] = state.get();
-    });
-    console.log('current state:', snapshots);
+    }
  }

  public undo() {
@@ -122,11 +137,13 @@ class Model {
    const item = ustack.pop();
    if (!item) return;
    const step: Snapshot[] = [];
-    item.forEach(([name, data]) => {
-      const { get, set } = store.get(name)!;
+    for (const [name, data] of item) {
+      const entry = store.get(name);
+      if (!entry) continue;
+      const { get, set } = entry;
      step.push([name, get()]);
      set(data);
-    });
+    }
    rstack.push(step);
    this.triggerStackState();
  }
@@ -136,11 +153,13 @@ class Model {
    const item = rstack.pop();
    if (!item) return;
    const step: Snapshot[] = [];
-    item.forEach(([name, data]) => {
-      const { get, set } = store.get(name)!;
+    for (const [name, data] of item) {
+      const entry = store.get(name);
+      if (!entry) continue;
+      const { get, set } = entry;
      step.push([name, get()]);
      set(data);
-    });
+    }
    ustack.push(step);
    this.triggerStackState();
  }
@@ -156,10 +175,10 @@ class Model {
  public startTransaction() {
    if (this.transaction === 0) {
      this.backup.clear();
-      this.store.forEach((state, name) => {
-        if (state.onlyView) return;
+      for (const [name, state] of this.store) {
+        if (state.onlyView) continue;
        this.backup.set(name, state.get());
-      });
+      }
    }
    this.transaction += 1;
    return this.endTransaction;
@@ -170,24 +189,26 @@ class Model {
    this.transaction -= 1;
    if (this.transaction === 0) {
      const changes: Snapshot[] = [];
-      this.store.forEach((state, name) => {
-        if (state.onlyView) return;
+      for (const [name, state] of this.store) {
+        if (state.onlyView) continue;
        const before = this.backup.get(name);
-        if (Object.is(before, state.get())) return;
+        if (Object.is(before, state.get())) continue;
        changes.push([name, before]);
-      });
+      }
      this.backup.clear();
      if (changes.length === 0) return;
      this.ustack.push(changes);
      this.rstack.length = 0;
      this.triggerStackState();
    }
-  }
+  };
 }

 function build() {
+  // biome-ignore lint/suspicious/noExplicitAny: store holds heterogeneous state types
  const store = new Map<string, State<any, any>>();

+  // biome-ignore lint/suspicious/noExplicitAny: memo cache stores heterogeneous values
  const mem: Record<string, any> = {};
  function use<T, A>(m: SubModel<T, A>): [T, A] {
    const state = query(m);
@@ -195,8 +216,8 @@ function build() {
  }

  const model = new Model(store, use);
-  if (process.env.NODE_ENV === 'development') {
-    // @ts-ignore
+  if (process.env.NODE_ENV === "development") {
+    // @ts-expect-error
    window.__md__ = model;
  }

@@ -206,9 +227,9 @@ function build() {
    const created = m.gen(model);
    store.set(m.name, created);
    return created;
-  };
+  }

-  return { query, model, mem, use }
+  return { query, model, mem, use };
 }

 const Context = createContext(build());
@@ -222,24 +243,28 @@ export function RegisterFlowToContext() {
  const instance = useReactFlow<AnyWorkNode>();
  useLayoutEffect(() => {
    model.flow = instance;
-  }, [instance]);
+  }, [instance, model]);
  return null;
 }

 export const ModelProvider: FC<PropsWithChildren> = (p) => (
-  <Context.Provider value={useMemo(build, [])}>
-    {p.children}
-  </Context.Provider>
+  <Context.Provider value={useMemo(build, [])}>{p.children}</Context.Provider>
 );

 function defineModel<T, A>(name: string, make: () => T, create: Create<T, A>) {
  return new SubModel<T, A>(name, make, create);
 }

+// biome-ignore lint/suspicious/noExplicitAny: default create returns setter directly
 const defaultCreate: Create<any, Setter<any>> = (set) => set;
-function defineView<T, A>(name: string, make: () => T, create: Create<T, A>): SubModel<T, A>
-function defineView<T>(name: string, make: () => T): SubModel<T, Setter<T>>
-function defineView<T>(name: string, make: () => T, create?: any): any {
+function defineView<T, A>(name: string, make: () => T, create: Create<T, A>): SubModel<T, A>;
+function defineView<T>(name: string, make: () => T): SubModel<T, Setter<T>>;
+function defineView<T>(
+  name: string,
+  make: () => T,
+  create?: Create<T, unknown>,
+): SubModel<T, unknown> {
+  // biome-ignore lint/suspicious/noExplicitAny: wraps into SubModel with erased action type
  return new SubModel<T, any>(name, make, create ?? defaultCreate, true);
 }

@@ -247,9 +272,12 @@ function memoize<T>(init: (use: Use, model: Model) => T) {
  const id = uuid();
  return {
    use(): T {
+      // biome-ignore lint/correctness/useHookAtTopLevel: use() is called as a hook by consumers
      const { mem, model, use } = useContext(Context);
-      const fn = mem[id] || (mem[id] = init(use, model));
-      return fn as T;
+      if (!mem[id]) {
+        mem[id] = init(use, model);
+      }
+      return mem[id] as T;
    },
  };
 }
@@ -258,21 +286,29 @@ function compute<T>(calc: (use: UseV) => T) {
  const id = uuid();
  return {
    use(): T {
+      // biome-ignore lint/correctness/useHookAtTopLevel: use() is called as a hook by consumers
      const { mem, query } = useContext(Context);
      let state: ReturnType<typeof generate<T>> = mem[id];
      if (state) return state.use();

+      // biome-ignore lint/suspicious/noExplicitAny: deps collect heterogeneous SubModels
      const deps = new Set<SubModel<any, any>>();
-      let usev = (m: SubModel<any, any>) => (deps.add(m), query(m).get());
+      // biome-ignore lint/suspicious/noExplicitAny: useV erases action type
+      let usev = (m: SubModel<any, any>) => {
+        deps.add(m);
+        return query(m).get();
+      };
      mem[id] = state = generate<T>(calc(usev));
      if (deps.size) {
-        usev = m => query(m).get();
+        usev = (m) => query(m).get();
        const update = () => state.set(calc(usev));
-        deps.forEach(m => query(m).listen(update));
+        for (const m of deps) {
+          query(m).listen(update);
+        }
      }
      return state.use();
    },
-  }
+  };
 }

 export const define = {
@@ -1,15 +1,15 @@
 import {
-  getSmoothStepPath,
-  EdgeLabelRenderer,
-  useReactFlow,
-  type EdgeProps,
  type Edge,
+  EdgeLabelRenderer,
+  type EdgeProps,
+  getSmoothStepPath,
+  useReactFlow,
 } from "@xyflow/react";
-import { useState, useRef, useEffect, useMemo, type ReactNode } from "react";
 import { Check } from "lucide-react";
-import type { ConditionalEdge as ConditionalEdgeType } from "../type.ts";
-import { useModel } from "../context.tsx";
+import { type ReactNode, useEffect, useMemo, useRef, useState } from "react";
 import { cn } from "../../lib/utils.ts";
+import { useModel } from "../context.tsx";
+import type { ConditionalEdge as ConditionalEdgeType } from "../type.ts";

 const SOURCE_COLOR = "#10b981";
 const TARGET_COLOR = "#3b82f6";
@@ -38,7 +38,7 @@ function GradientPath({
  const gradientId = `gradient-${id}`;
  const showLack = hasCondition === false;
  const strokeStyle = selected
-    ? { stroke: '#f59e0b', strokeWidth: 2 }
+    ? { stroke: "#f59e0b", strokeWidth: 2 }
    : { stroke: `url(#${gradientId})`, strokeWidth: 1.5 };

  return (
@@ -63,13 +63,7 @@ function GradientPath({
        strokeWidth={20}
        className="react-flow__edge-interaction"
      />
-      <path
-        id={id}
-        d={path}
-        fill="none"
-        className="react-flow__edge-path"
-        style={strokeStyle}
-      />
+      <path id={id} d={path} fill="none" className="react-flow__edge-path" style={strokeStyle} />
    </>
  );
 }
@@ -143,13 +137,12 @@ function ConditionLabel({ condition, labelX, labelY, onSave }: ConditionLabelPro
      }}
      onPointerDown={(e) => e.stopPropagation()}
    >
+      {/* biome-ignore lint/a11y/noStaticElementInteractions: click handler on badge label */}
      <div onClick={handleBadgeClick} onKeyDown={undefined} className="cursor-pointer">
        <span
          className={cn(
            "inline-block px-1 bg-white rounded text-[10px]",
-            condition
-              ? "border border-gray-300 text-black"
-              : "border border-dashed text-red-500",
+            condition ? "border border-gray-300 text-black" : "border border-dashed text-red-500",
          )}
          style={condition ? undefined : { borderColor: LACK_COLOR }}
        >
@@ -166,7 +159,6 @@ function ConditionLabel({ condition, labelX, labelY, onSave }: ConditionLabelPro
              value={inputValue}
              onChange={(e) => setInputValue(e.target.value)}
              onKeyDown={handleKeyDown}
-              autoFocus
            />
            <button
              type="button"
@@ -183,7 +175,7 @@ function ConditionLabel({ condition, labelX, labelY, onSave }: ConditionLabelPro
 }

 export function isElseEdge(edgeId: string, source: string, allEdges: Edge[]): boolean {
-  const siblings = allEdges.filter(e => e.source === source && e.type === 'conditional');
+  const siblings = allEdges.filter((e) => e.source === source && e.type === "conditional");
  return siblings.length >= 2 && siblings[0].id === edgeId;
 }

@@ -200,7 +192,13 @@ export function ConditionalEdge({
  data,
 }: EdgeProps<ConditionalEdgeType>): ReactNode {
  const [edgePath, labelX, labelY] = getSmoothStepPath({
-    sourceX, sourceY, targetX, targetY, sourcePosition, targetPosition, borderRadius: RADIUS,
+    sourceX,
+    sourceY,
+    targetX,
+    targetY,
+    sourcePosition,
+    targetPosition,
+    borderRadius: RADIUS,
  });
  const flow = useReactFlow();
  const model = useModel();
@@ -224,14 +222,20 @@ export function ConditionalEdge({
        sourceY={sourceY}
        targetX={targetX}
        targetY={targetY}
-        hasCondition={isElse ? null : (condition ? true : false)}
+        hasCondition={isElse ? null : !!condition}
        selected={!!selected}
      />
      <EdgeLabelRenderer>
-        {isElse
-          ? <ElseBadge labelX={labelX} labelY={labelY} />
-          : <ConditionLabel condition={condition} labelX={labelX} labelY={labelY} onSave={handleSave} />
-        }
+        {isElse ? (
+          <ElseBadge labelX={labelX} labelY={labelY} />
+        ) : (
+          <ConditionLabel
+            condition={condition}
+            labelX={labelX}
+            labelY={labelY}
+            onSave={handleSave}
+          />
+        )}
      </EdgeLabelRenderer>
    </>
  );
@@ -248,7 +252,13 @@ export function GradientEdge({
  selected,
 }: EdgeProps<Edge>): ReactNode {
  const [edgePath] = getSmoothStepPath({
-    sourceX, sourceY, targetX, targetY, sourcePosition, targetPosition, borderRadius: RADIUS,
+    sourceX,
+    sourceY,
+    targetX,
+    targetY,
+    sourcePosition,
+    targetPosition,
+    borderRadius: RADIUS,
  });

  return (
@@ -1,4 +1,4 @@
-import { ConditionalEdge, GradientEdge } from './conditional';
+import { ConditionalEdge, GradientEdge } from "./conditional";

 export const edgeTypes = {
  conditional: ConditionalEdge,
@@ -1,16 +1,16 @@
-import { memo, createElement, useLayoutEffect, useEffect, createContext, useContext } from 'react';
-import { ReactFlow, ReactFlowProvider, Controls, Background, type Edge } from '@xyflow/react';
-// @ts-ignore
-import '@xyflow/react/dist/style.css';
-import { nodesModel, edgesModel, handlers, injection }  from './model';
-import { ModelProvider, RegisterFlowToContext } from './context';
-import { nodeTypes } from './nodes';
-import { edgeTypes } from './edges';
-import { Dialogs, TopCenterPanel } from './panel';
-import type { AnyWorkNode } from './type';
-import { FlowModel, InternalField } from './injection';
+import { Background, Controls, type Edge, ReactFlow, ReactFlowProvider } from "@xyflow/react";
+import { createContext, createElement, memo, useContext, useEffect, useLayoutEffect } from "react";
+// @ts-expect-error
+import "@xyflow/react/dist/style.css";
+import { ModelProvider, RegisterFlowToContext } from "./context";
+import { edgeTypes } from "./edges";
+import { FlowModel, InternalField } from "./injection";
+import { edgesModel, handlers, injection, nodesModel } from "./model";
+import { nodeTypes } from "./nodes";
+import { Dialogs, TopCenterPanel } from "./panel";
+import type { AnyWorkNode } from "./type";

-export * from './trans/type';
+export * from "./trans/type";

 const proOptions = { hideAttribution: true };

@@ -20,11 +20,13 @@ export const useReadonly = () => useContext(ReadonlyContext);
 function Flow() {
  const [nodes, { onNodesChange }] = nodesModel.use();
  const [edges, { onEdgesChange, onConnect }] = edgesModel.use();
-  const { onNodeDragStart, onNodeDragStop, onConnectEnd, onBeforeDelete, onDelete, handleKeyDown } = handlers.use();
+  const { onNodeDragStart, onNodeDragStop, onConnectEnd, onBeforeDelete, onDelete, handleKeyDown } =
+    handlers.use();
  const readonly = useReadonly();

  return (
-    <div style={{ height: '100%' }} tabIndex={0} onKeyDown={readonly ? undefined : handleKeyDown}>
+    // biome-ignore lint/a11y/noStaticElementInteractions: keyboard handler for flow shortcuts
+    <div style={{ height: "100%" }} onKeyDown={readonly ? undefined : handleKeyDown}>
      <ReactFlowProvider>
        <ReactFlow<AnyWorkNode, Edge>
          nodes={nodes}
@@ -70,11 +72,11 @@ function Connect({ model }: { model: FlowModel }) {

  useLayoutEffect(() => {
    return inject(instance);
-  }, [instance]);
+  }, [instance, inject]);

  useEffect(() => {
-    return instance.on('load', loadSteps);
-  }, [instance]);
+    return instance.on("load", loadSteps);
+  }, [instance, loadSteps]);

  return <MemoFlow />;
 }
@@ -83,8 +85,6 @@ export { FlowModel };
 // biome-ignore lint/style/noDefaultExport: FlowEditor is the main public component
 export default ({ model, readonly = false }: Props) => (
  <ReadonlyContext.Provider value={readonly}>
-    <ModelProvider>
-      {createElement(Connect, { model })}
-    </ModelProvider>
+    <ModelProvider>{createElement(Connect, { model })}</ModelProvider>
  </ReadonlyContext.Provider>
 );
@@ -1,5 +1,5 @@
-import { WorkFlowSteps } from "./trans";
-import { Eventer } from './utils/eventer';
+import type { WorkFlowSteps } from "./trans";
+import { Eventer } from "./utils/eventer";

 interface PublicEvents {
  save: WorkFlowSteps;
@@ -9,19 +9,21 @@ interface PrivateEvents {
  load: WorkFlowSteps;
 }

-export const InternalField = Symbol('InternalField');
+export const InternalField = Symbol("InternalField");

 export class Injection extends Eventer<PrivateEvents> {
-  constructor(
-    public readonly emitPublic: Eventer<PublicEvents>['emit'],
-    private inital_steps?: WorkFlowSteps,
-  ) {
+  public readonly emitPublic: Eventer<PublicEvents>["emit"];
+  private inital_steps: WorkFlowSteps | undefined;
+
+  constructor(emitPublic: Eventer<PublicEvents>["emit"], inital_steps?: WorkFlowSteps) {
    super();
+    this.emitPublic = emitPublic;
+    this.inital_steps = inital_steps;
  }

-  public on: Eventer<PrivateEvents>['on'] = (type, lisenter) => {
-    const off =  super.on(type, lisenter);
-    if (type === 'load' && this.inital_steps) {
+  public on: Eventer<PrivateEvents>["on"] = (type, lisenter) => {
+    const off = super.on(type, lisenter);
+    if (type === "load" && this.inital_steps) {
      lisenter(this.inital_steps);
      this.inital_steps = undefined;
    }
@@ -37,13 +39,10 @@ export class FlowModel {
  public readonly [InternalField]: Injection;

  constructor(inital_steps?: WorkFlowSteps) {
-    this[InternalField] = new Injection(
-      this.eventer.emit.bind(this.eventer),
-      inital_steps,
-    );
+    this[InternalField] = new Injection(this.eventer.emit.bind(this.eventer), inital_steps);
  }

  public load(steps: WorkFlowSteps) {
-    this[InternalField].emit('load', steps);
+    this[InternalField].emit("load", steps);
  }
 }
@@ -0,0 +1,83 @@
+import type { Edge, Node } from "@xyflow/react";
+import { describe, expect, it } from "vitest";
+import { LayoutLR } from "../index.js";
+
+function makeNode(id: string): Node {
+  return { id, type: "role", data: {}, position: { x: 0, y: 0 } } as Node;
+}
+
+function makeEdge(source: string, target: string): Edge {
+  return { id: `${source}-${target}`, source, target } as Edge;
+}
+
+describe("LayoutLR / assignLayers", () => {
+  it("1.1 Empty graph: start gets layer 0, end gets higher layer", () => {
+    const nodes = [makeNode("start"), makeNode("end")];
+    const result = LayoutLR(nodes, []);
+    const start = result.find((n) => n.id === "start");
+    const end = result.find((n) => n.id === "end");
+    // start has no position change necessarily, but positions should be assigned
+    expect(start).toBeDefined();
+    expect(end).toBeDefined();
+    // end should be to the right of start
+    expect((end?.position.x ?? 0) > (start?.position.x ?? 0)).toBe(true);
+  });
+
+  it("1.2 Linear chain: start → A → B → end — layers assigned in order", () => {
+    const nodes = [makeNode("start"), makeNode("A"), makeNode("B"), makeNode("end")];
+    const edges = [makeEdge("start", "A"), makeEdge("A", "B"), makeEdge("B", "end")];
+    const result = LayoutLR(nodes, edges);
+    const xOf = (id: string) => result.find((n) => n.id === id)?.position.x ?? 0;
+    expect(xOf("start") < xOf("A")).toBe(true);
+    expect(xOf("A") < xOf("B")).toBe(true);
+    expect(xOf("B") < xOf("end")).toBe(true);
+  });
+
+  it("1.3 Diamond: A and B share same layer", () => {
+    const nodes = [makeNode("start"), makeNode("A"), makeNode("B"), makeNode("C"), makeNode("end")];
+    const edges = [
+      makeEdge("start", "A"),
+      makeEdge("start", "B"),
+      makeEdge("A", "C"),
+      makeEdge("B", "C"),
+      makeEdge("C", "end"),
+    ];
+    const result = LayoutLR(nodes, edges);
+    const xOf = (id: string) => result.find((n) => n.id === id)?.position.x ?? 0;
+    expect(xOf("A")).toBe(xOf("B")); // same layer
+    expect(xOf("A") < xOf("C")).toBe(true);
+    expect(xOf("C") < xOf("end")).toBe(true);
+  });
+
+  it("1.4 Isolated node placed in middle layer (not layer 0, not end layer)", () => {
+    const nodes = [makeNode("start"), makeNode("A"), makeNode("isolated"), makeNode("end")];
+    const edges = [makeEdge("start", "A"), makeEdge("A", "end")];
+    const result = LayoutLR(nodes, edges);
+    const xOf = (id: string) => result.find((n) => n.id === id)?.position.x ?? 0;
+    const xIsolated = xOf("isolated");
+    expect(xIsolated > xOf("start")).toBe(true);
+    expect(xIsolated < xOf("end")).toBe(true);
+  });
+
+  it("1.5 end node is always last (highest x)", () => {
+    const nodes = [makeNode("start"), makeNode("A"), makeNode("B"), makeNode("end")];
+    const edges = [makeEdge("start", "A"), makeEdge("A", "B"), makeEdge("B", "end")];
+    const result = LayoutLR(nodes, edges);
+    const endX = result.find((n) => n.id === "end")?.position.x ?? 0;
+    for (const node of result) {
+      if (node.id !== "end") {
+        expect(node.position.x < endX).toBe(true);
+      }
+    }
+  });
+
+  it("1.6 start node is always first (x = 0 or smallest x)", () => {
+    const nodes = [makeNode("start"), makeNode("A"), makeNode("end")];
+    const edges = [makeEdge("start", "A"), makeEdge("A", "end")];
+    const result = LayoutLR(nodes, edges);
+    const startX = result.find((n) => n.id === "start")?.position.x ?? 0;
+    for (const node of result) {
+      expect(node.position.x >= startX).toBe(true);
+    }
+  });
+});
@@ -1,4 +1,4 @@
-import { Node, Edge } from '@xyflow/react';
+import type { Edge, Node } from "@xyflow/react";

 const DEFAULT_NODE_WIDTH = 120;
 const DEFAULT_NODE_HEIGHT = 50;
@@ -34,8 +34,8 @@ function buildGraph(nodes: Node[], edges: Edge[]) {
  // 构建图
  for (const edge of edges) {
    if (nodeIds.has(edge.source) && nodeIds.has(edge.target)) {
-      outgoing.get(edge.source)!.push(edge.target);
-      incoming.get(edge.target)!.push(edge.source);
+      outgoing.get(edge.source)?.push(edge.target);
+      incoming.get(edge.target)?.push(edge.source);
      inDegree.set(edge.target, (inDegree.get(edge.target) ?? 0) + 1);
    }
  }
@@ -43,6 +43,65 @@ function buildGraph(nodes: Node[], edges: Edge[]) {
  return { outgoing, incoming, inDegree };
 }

+function processTarget(
+  target: string,
+  newLayer: number,
+  layers: Map<string, number>,
+  inDegree: Map<string, number>,
+  queue: string[],
+): void {
+  const existingLayer = layers.get(target);
+  if (existingLayer === undefined) {
+    layers.set(target, newLayer);
+    inDegree.set(target, (inDegree.get(target) ?? 1) - 1);
+    if (inDegree.get(target) === 0) queue.push(target);
+  } else {
+    layers.set(target, Math.max(existingLayer, newLayer));
+  }
+}
+
+/**
+ * BFS 分层（排除 end 节点，稍后单独处理）
+ */
+function bfsLayers(
+  outgoing: Map<string, string[]>,
+  inDegree: Map<string, number>,
+  layers: Map<string, number>,
+): void {
+  const queue: string[] = ["start"];
+  while (queue.length > 0) {
+    const current = queue.shift() ?? "";
+    const currentLayer = layers.get(current) ?? 0;
+    for (const target of outgoing.get(current) ?? []) {
+      if (target === "end") continue;
+      processTarget(target, currentLayer + 1, layers, inDegree, queue);
+    }
+  }
+}
+
+/**
+ * 处理孤立节点（没有被分配层级的非 start/end 节点），放在中间层
+ */
+function placeIsolatedNodes(nodes: Node[], layers: Map<string, number>, maxLayer: number): void {
+  const middleLayer = Math.max(1, Math.floor((maxLayer + 1) / 2));
+  for (const node of nodes) {
+    if (node.id !== "start" && node.id !== "end" && !layers.has(node.id)) {
+      layers.set(node.id, middleLayer);
+    }
+  }
+}
+
+/**
+ * 计算最大层级（排除 end 节点）
+ */
+function maxLayerExcludingEnd(layers: Map<string, number>): number {
+  let max = 0;
+  for (const [id, layer] of layers) {
+    if (id !== "end") max = Math.max(max, layer);
+  }
+  return max;
+}
+
 /**
 * 使用拓扑排序将节点分层
 * - 'start' 节点固定在第 0 层
@@ -52,62 +111,15 @@ function buildGraph(nodes: Node[], edges: Edge[]) {
 function assignLayers(nodes: Node[], edges: Edge[]): Map<string, number> {
  const { outgoing, inDegree } = buildGraph(nodes, edges);
  const layers = new Map<string, number>();
-  const queue: string[] = [];

-  // 1. start 节点固定在第 0 层
-  layers.set('start', 0);
-  queue.push('start');
+  layers.set("start", 0);
+  bfsLayers(outgoing, inDegree, layers);

-  // 2. BFS 分层（排除 end 节点，稍后单独处理）
-  while (queue.length > 0) {
-    const current = queue.shift()!;
-    const currentLayer = layers.get(current)!;
+  const afterBfsMax = maxLayerExcludingEnd(layers);
+  placeIsolatedNodes(nodes, layers, afterBfsMax);

-    for (const target of outgoing.get(current) ?? []) {
-      // 跳过 end 节点，稍后处理
-      if (target === 'end') continue;
-
-      const newLayer = currentLayer + 1;
-      const existingLayer = layers.get(target);
-
-      if (existingLayer === undefined) {
-        layers.set(target, newLayer);
-        inDegree.set(target, (inDegree.get(target) ?? 1) - 1);
-        if (inDegree.get(target) === 0) {
-          queue.push(target);
-        }
-      } else {
-        // 如果已有层级，取更大的值（确保所有前驱都在前面）
-        layers.set(target, Math.max(existingLayer, newLayer));
-      }
-    }
-  }
-
-  // 3. 找到当前最大层级
-  let maxLayer = 0;
-  for (const layer of layers.values()) {
-    maxLayer = Math.max(maxLayer, layer);
-  }
-
-  // 4. 处理孤立节点（没有被分配层级的非 start/end 节点）
-  // 把它们放在中间层
-  const middleLayer = Math.max(1, Math.floor((maxLayer + 1) / 2));
-  for (const node of nodes) {
-    if (node.id !== 'start' && node.id !== 'end' && !layers.has(node.id)) {
-      layers.set(node.id, middleLayer);
-    }
-  }
-
-  // 5. 重新计算最大层级（可能因为孤立节点而变化）
-  maxLayer = 0;
-  for (const [id, layer] of layers) {
-    if (id !== 'end') {
-      maxLayer = Math.max(maxLayer, layer);
-    }
-  }
-
-  // 6. end 节点固定在最后一层
-  layers.set('end', maxLayer + 1);
+  const finalMax = maxLayerExcludingEnd(layers);
+  layers.set("end", finalMax + 1);

  return layers;
 }
@@ -123,7 +135,7 @@ function groupByLayer<N extends Node>(nodes: N[], layers: Map<string, number>):
    if (!groups.has(layer)) {
      groups.set(layer, []);
    }
-    groups.get(layer)!.push(node);
+    groups.get(layer)?.push(node);
  }

  return groups;
@@ -152,7 +164,7 @@ function calculateLayerWidths(layerGroups: Map<number, Node[]>): Map<number, num
 */
 function calculateLayerXPositions(
  layerWidths: Map<number, number>,
-  maxLayer: number
+  maxLayer: number,
 ): Map<number, number> {
  const xPositions = new Map<number, number>();
  let currentX = 0;
@@ -1,13 +1,13 @@
-import type { Edge } from '@xyflow/react';
-import { define } from '../context';
-import { nodesModel } from './nodes';
-import { edgesModel } from './edges';
-import type { RoleNodeData, AnyWorkNode } from '../type';
+import type { Edge } from "@xyflow/react";
+import { define } from "../context";
+import type { AnyWorkNode, RoleNodeData } from "../type";
+import { edgesModel } from "./edges";
+import { nodesModel } from "./nodes";

 type ConnectHandle = {
  id?: string | null;
  nodeId: string;
-  type: 'source' | 'target';
+  type: "source" | "target";
 };

 export type AddNodeState = {
@@ -21,10 +21,10 @@ type CommitParams = {
 };

 function addNodeView() {
-  return null as (AddNodeState | null);
+  return null as AddNodeState | null;
 }

-export const addNodeViewModel = define.view('addNodeView', addNodeView, (set, get, model) => {
+export const addNodeViewModel = define.view("addNodeView", addNodeView, (set, get, model) => {
  function start(state: AddNodeState) {
    set(state);
  }
@@ -42,12 +42,19 @@ export const addNodeViewModel = define.view('addNodeView', addNodeView, (set, ge
    const { data } = params;

    const id = `n${Date.now()}`;
-    const node = { id, data, position, type: 'role' as const, origin: [0.0, 0.5] as [number, number] };
+    const node = {
+      id,
+      data,
+      position,
+      type: "role" as const,
+      origin: [0.0, 0.5] as [number, number],
+    };

    const [fnid, fhid] = [fromNode.id, fromHandle.id];
-    const newEdge: Edge = fromHandle.type === 'source'
-      ? { id: `e${fnid}-${id}`, source: fnid, target: id, sourceHandle: fhid, animated: true }
-      : { id: `e${id}-${fnid}`, source: id, target: fnid, targetHandle: fhid, animated: true };
+    const newEdge: Edge =
+      fromHandle.type === "source"
+        ? { id: `e${fnid}-${id}`, source: fnid, target: id, sourceHandle: fhid, animated: true }
+        : { id: `e${id}-${fnid}`, source: id, target: fnid, targetHandle: fhid, animated: true };

    model.startTransaction();
    model.use(nodesModel)[1].set((nds) => nds.concat(node));
@@ -1,21 +1,16 @@
-import {
-  applyEdgeChanges,
-  type Edge,
-  type EdgeChange,
-  type Connection,
-} from '@xyflow/react';
-import { define } from '../context';
+import { applyEdgeChanges, type Connection, type Edge, type EdgeChange } from "@xyflow/react";
+import { define } from "../context";

 function makeEdges(): Edge[] {
  return [];
 }

 function isInputHandle(handle: string | null | undefined): boolean {
-  return handle === 'input' || handle === 'input-top' || handle === 'input-bottom';
+  return handle === "input" || handle === "input-top" || handle === "input-bottom";
 }

 function isOutputHandle(handle: string | null | undefined): boolean {
-  return handle === 'output' || handle === 'output-top' || handle === 'output-bottom';
+  return handle === "output" || handle === "output-top" || handle === "output-bottom";
 }

 function normalizeConnection(params: Edge | Connection): Edge | Connection {
@@ -33,10 +28,10 @@ function normalizeConnection(params: Edge | Connection): Edge | Connection {

 let edgeCounter = 0;

-export const edgesModel = define.model('edges', makeEdges, (set, get, model) => {
+export const edgesModel = define.model("edges", makeEdges, (set, get, model) => {
  function onEdgesChange(changes: EdgeChange[]) {
-    const whites = new Set(['add', 'replace']);
-    if (changes.some(c => whites.has(c.type))) {
+    const whites = new Set(["add", "replace"]);
+    if (changes.some((c) => whites.has(c.type))) {
      model.startTransaction();
      set((eds) => applyEdgeChanges(changes, eds));
      requestAnimationFrame(model.endTransaction);
@@ -54,7 +49,7 @@ export const edgesModel = define.model('edges', makeEdges, (set, get, model) =>

    const currentEdges = get();
    const duplicate = currentEdges.some(
-      e => e.source === normalized.source && e.target === normalized.target,
+      (e) => e.source === normalized.source && e.target === normalized.target,
    );
    if (duplicate) return;

@@ -67,15 +62,15 @@ export const edgesModel = define.model('edges', makeEdges, (set, get, model) =>
      animated: true,
    } as Edge;

-    const existingFromSource = currentEdges.filter(e => e.source === normalized.source);
+    const existingFromSource = currentEdges.filter((e) => e.source === normalized.source);

    if (existingFromSource.length > 0) {
-      edge.type = 'conditional';
-      edge.data = { condition: '' };
+      edge.type = "conditional";
+      edge.data = { condition: "" };

-      const promoted = currentEdges.map(e => {
-        if (e.source === normalized.source && e.type !== 'conditional') {
-          return { ...e, type: 'conditional' as const, data: { condition: '' } };
+      const promoted = currentEdges.map((e) => {
+        if (e.source === normalized.source && e.type !== "conditional") {
+          return { ...e, type: "conditional" as const, data: { condition: "" } };
        }
        return e;
      });
@@ -1,21 +1,21 @@
-import { define } from '../context';
-import { nodesModel } from './nodes';
-import type { RoleNodeData, WorkNode } from '../type';
+import { define } from "../context";
+import type { RoleNodeData, WorkNode } from "../type";
+import { nodesModel } from "./nodes";

 export type EditNodeState = {
-  node: WorkNode<'role'>;
+  node: WorkNode<"role">;
 };

 function editNodeView() {
-  return null as (EditNodeState | null);
+  return null as EditNodeState | null;
 }

-export const editNodeViewModel = define.view('editNodeView', editNodeView, (set, get, model) => {
+export const editNodeViewModel = define.view("editNodeView", editNodeView, (set, get, model) => {
  function start(nodeId: string) {
    const [nodes] = model.use(nodesModel);
-    const node = nodes.find(n => n.id === nodeId);
-    if (!node || node.type !== 'role') return;
-    set({ node: node as WorkNode<'role'> });
+    const node = nodes.find((n) => n.id === nodeId);
+    if (!node || node.type !== "role") return;
+    set({ node: node as WorkNode<"role"> });
  }

  function cancel() {
@@ -31,6 +31,7 @@ export const editNodeViewModel = define.view('editNodeView', editNodeView, (set,

    model.startTransaction();
    editNode(state.node.id, (node) => {
+      // biome-ignore lint/suspicious/noExplicitAny: node data type varies by node kind
      node.data = data as any;
    });
    requestAnimationFrame(model.endTransaction);
@@ -1,14 +1,14 @@
-import type { OnNodeDrag, OnConnectEnd, OnBeforeDelete, OnDelete } from '@xyflow/react';
-import { define } from '../context';
-import { addNodeViewModel } from './add-node-view';
-import type { AnyWorkNode } from '../type';
-import { LayoutLR } from '../layout';
-import { nodesModel } from './nodes';
-import { edgesModel } from './edges';
-import { injection } from './inject';
-import { transIn, transOut, validate } from '../trans';
-import type { WorkFlowSteps } from '../trans';
-import { editNodeViewModel } from './edit-node-view';
+import type { OnBeforeDelete, OnConnectEnd, OnDelete, OnNodeDrag } from "@xyflow/react";
+import { define } from "../context";
+import { LayoutLR } from "../layout";
+import type { WorkFlowSteps } from "../trans";
+import { transIn, transOut, validate } from "../trans";
+import type { AnyWorkNode } from "../type";
+import { addNodeViewModel } from "./add-node-view";
+import { edgesModel } from "./edges";
+import { editNodeViewModel } from "./edit-node-view";
+import { injection } from "./inject";
+import { nodesModel } from "./nodes";

 export const handlers = define.memoize((use, model) => {
  const onNodeDragStart: OnNodeDrag<AnyWorkNode> = () => {
@@ -23,27 +23,31 @@ export const handlers = define.memoize((use, model) => {
    if (!to || !fromHandle || !fromNode) return;
    const { clientX, clientY } = event as MouseEvent;
    use(addNodeViewModel)[1].start({
+      // biome-ignore lint/suspicious/noExplicitAny: ReactFlow node type mismatch
      fromNode: fromNode as any as AnyWorkNode,
      fromHandle: fromHandle,
      position: model.flow.screenToFlowPosition({ x: clientX, y: clientY }),
    });
  };

+  function isProtectedNode(node: AnyWorkNode): boolean {
+    return node.type === "start" || node.type === "end";
+  }
+
+  function isFirstConditionalSibling(
+    edge: { id: string; source: string; type: string | null },
+    allEdges: { id: string; source: string; type: string | null }[],
+  ): boolean {
+    if (edge.type !== "conditional") return false;
+    const siblings = allEdges.filter((e) => e.source === edge.source && e.type === "conditional");
+    return siblings.length >= 2 && siblings[0].id === edge.id;
+  }
+
  const onBeforeDelete: OnBeforeDelete<AnyWorkNode> = async ({ nodes, edges }) => {
-    for (const node of nodes) {
-      if (node.type === 'start' || node.type === 'end') {
-        return false;
-      }
-    }
+    if (nodes.some(isProtectedNode)) return false;
    if (edges.length > 0) {
      const allEdges = use(edgesModel)[0];
-      for (const edge of edges) {
-        if (edge.type !== 'conditional') continue;
-        const siblings = allEdges.filter(e => e.source === edge.source && e.type === 'conditional');
-        if (siblings.length >= 2 && siblings[0].id === edge.id) {
-          return false;
-        }
-      }
+      if (edges.some((e) => isFirstConditionalSibling(e, allEdges))) return false;
    }
    model.startTransaction();
    return true;
@@ -52,20 +56,20 @@ export const handlers = define.memoize((use, model) => {
    if (deletedEdges.length > 0) {
      const currentEdges = use(edgesModel)[0];
      const sourcesToCheck = new Set(
-        deletedEdges
-          .filter(e => e.type === 'conditional')
-          .map(e => e.source),
+        deletedEdges.filter((e) => e.type === "conditional").map((e) => e.source),
      );

      if (sourcesToCheck.size > 0) {
        let needsDowngrade = false;
-        const updatedEdges = currentEdges.map(e => {
-          if (!sourcesToCheck.has(e.source) || e.type !== 'conditional') return e;
-          const siblings = currentEdges.filter(s => s.source === e.source && s.type === 'conditional');
+        const updatedEdges = currentEdges.map((e) => {
+          if (!sourcesToCheck.has(e.source) || e.type !== "conditional") return e;
+          const siblings = currentEdges.filter(
+            (s) => s.source === e.source && s.type === "conditional",
+          );
          if (siblings.length === 1) {
            needsDowngrade = true;
            const { data: _, ...rest } = e;
-            return { ...rest, type: 'default' as const };
+            return { ...rest, type: "default" as const };
          }
          return e;
        });
@@ -93,25 +97,28 @@ export const handlers = define.memoize((use, model) => {
    use(editNodeViewModel)[1].cancel();
  }

+  function handleEscape() {
+    const [addView, addViewActions] = use(addNodeViewModel);
+    const [editView, editViewActions] = use(editNodeViewModel);
+    if (addView) addViewActions.cancel();
+    if (editView) editViewActions.cancel();
+  }
+
+  function handleUndoRedo(event: React.KeyboardEvent<HTMLDivElement>) {
+    if (event.code === "KeyZ" && (event.ctrlKey || event.metaKey)) {
+      if (event.shiftKey) model.redo();
+      else model.undo();
+    } else if (event.code === "KeyY" && (event.ctrlKey || event.metaKey)) {
+      model.redo();
+    }
+  }
+
  function handleKeyDown(event: React.KeyboardEvent<HTMLDivElement>) {
-    if (event.code === 'Escape') {
-      const [addView, addViewActions] = use(addNodeViewModel);
-      const [editView, editViewActions] = use(editNodeViewModel);
-      if (addView) addViewActions.cancel();
-      if (editView) editViewActions.cancel();
+    if (event.code === "Escape") {
+      handleEscape();
      return;
    }
-
-    if (event.code === 'KeyZ') {
-      if (event.ctrlKey || event.metaKey) {
-        if (event.shiftKey) model.redo();
-        else model.undo();
-      }
-    } else if (event.code === 'KeyY') {
-      if (event.ctrlKey || event.metaKey) {
-        model.redo();
-      }
-    }
+    handleUndoRedo(event);
  }

  function loadSteps(steps: WorkFlowSteps) {
@@ -130,7 +137,7 @@ export const handlers = define.memoize((use, model) => {
    if (result.valid) {
      const steps = transOut(nodes, edges);
      const instance = use(injection)[0];
-      instance.emitPublic('save', steps);
+      instance.emitPublic("save", steps);
    }
    return result;
  }
@@ -1,6 +1,6 @@
-export { nodesModel } from './nodes';
-export { edgesModel } from './edges';
-export { addNodeViewModel, type AddNodeState } from './add-node-view';
-export { editNodeViewModel, type EditNodeState } from './edit-node-view';
-export { handlers } from './handlers';
-export { injection } from './inject';
+export { type AddNodeState, addNodeViewModel } from "./add-node-view";
+export { edgesModel } from "./edges";
+export { type EditNodeState, editNodeViewModel } from "./edit-node-view";
+export { handlers } from "./handlers";
+export { injection } from "./inject";
+export { nodesModel } from "./nodes";
@@ -3,8 +3,7 @@
 */

 import { define } from "../context.tsx";
-import { Injection } from '../injection.ts';
-
+import { Injection } from "../injection.ts";

 const NOOP = () => {};
 const placeholder = new Injection(NOOP);
@@ -13,7 +12,7 @@ function make(): Injection {
  return placeholder;
 }

-export const injection = define.view('injection', make, (set) => {
+export const injection = define.view("injection", make, (set) => {
  function reset() {
    set(make());
  }
@@ -1,48 +1,49 @@
-import { produce, type Draft } from 'immer';
-import { applyNodeChanges, NodeChange } from '@xyflow/react';
-import { define } from '../context';
-import type { AnyWorkNode } from '../type';
-
+import { applyNodeChanges, type NodeChange } from "@xyflow/react";
+import { type Draft, produce } from "immer";
+import { define } from "../context";
+import type { AnyWorkNode } from "../type";

 function makeNodes(): AnyWorkNode[] {
  return [
    {
-      id: 'start',
-      type: 'start',
-      data: { label: 'Start' },
+      id: "start",
+      type: "start",
+      data: { label: "Start" },
      position: { x: 0, y: 0 },
    },
    {
-      id: 'end',
-      data: { label: 'End' },
+      id: "end",
+      data: { label: "End" },
      position: { x: 1000, y: 0 },
-      type: 'end',
+      type: "end",
    },
  ];
 }

-export const nodesModel = define.model('nodes', makeNodes, (set, _get, model) => {
-  const whites = new Set<NodeChange['type']>(['add', 'replace']);
+export const nodesModel = define.model("nodes", makeNodes, (set, _get, model) => {
+  const whites = new Set<NodeChange["type"]>(["add", "replace"]);
  function onNodesChange(changes: NodeChange<AnyWorkNode>[]) {
-    if (changes.some(c => whites.has(c.type))) {
+    if (changes.some((c) => whites.has(c.type))) {
      model.startTransaction();
      set((nds) => applyNodeChanges(changes, nds));
      requestAnimationFrame(model.endTransaction);
      return;
    }
    set((nds) => applyNodeChanges(changes, nds));
-  };
+  }

  function editNode(id: string, updater: (node: Draft<AnyWorkNode>) => void) {
-    set(produce((draft) => {
-      const node = draft.find(n => n.id === id);
-      if (node) updater(node);
-    }));
+    set(
+      produce((draft) => {
+        const node = draft.find((n) => n.id === id);
+        if (node) updater(node);
+      }),
+    );
  }

  function deleteNode(id: string) {
    model.startTransaction();
-    set((nds) => nds.filter(n => n.id !== id));
+    set((nds) => nds.filter((n) => n.id !== id));
    requestAnimationFrame(model.endTransaction);
  }

--- a/Show More
+++ b/Show More