fix: add workspace path sandboxing and UWF_BUILTIN_ALLOW_SHELL check

- Add resolvePathInWorkspace() to reject paths escaping workspace root
- Apply sandboxing to read_file, write_file, and run_command tools
- Gate run_command behind UWF_BUILTIN_ALLOW_SHELL=1 env var
- Add tests for resolvePathInWorkspace escape detection

.workflows/solve-issue.yaml

@@ -38,12 +38,18 @@ roles:
     capabilities:
       - coding
     procedure: |
-      1. Read the test spec from CAS: `uwf cas get <plan hash>` (find the hash from the latest planner step's meta.plan)
-      2. If bounced back from reviewer or tester: read the previous role's output to understand what needs fixing
-      3. Write tests first based on the spec
-      4. Implement the code to make tests pass
-      5. Ensure `bun run build` passes with no errors
-      6. Run `bun test` to verify all tests pass
+      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
+
+      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
     output: "List all files changed and provide a summary. Frontmatter must include: status (done or failed)."
     frontmatter:
       type: object
@@ -59,10 +65,15 @@ roles:
       - code-review
       - static-analysis
     procedure: |
+      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
+
+      Then perform code review:
       Hard checks (must all pass):
-      1. `bun run build` — no build errors
-      2. `bunx biome check` — no lint violations
-      3. TypeScript strict mode — no type errors
+      3. `bun run build` — no build errors
+      4. `bunx biome check` — no lint violations
+      5. TypeScript strict mode — no type errors
 
       Soft checks (review against CLAUDE.md conventions):
       - Functional-first: `function` + `type`, not `class` + `interface`
@@ -88,7 +99,7 @@ roles:
       - testing
     procedure: |
       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 meta.plan)
+      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
       4. Determine outcome:
          - passed: all scenarios verified, tests pass
@@ -143,25 +154,43 @@ conditions:
 graph:
   $START:
     - role: "planner"
+      condition: null
+      prompt: "Analyze the issue and produce an implementation plan."
   planner:
     - role: "$END"
       condition: "insufficientInfo"
+      prompt: "Insufficient information to proceed; end the workflow."
     - role: "developer"
+      condition: null
+      prompt: "Implement the plan from the planner."
   developer:
     - role: "$END"
       condition: "devFailed"
+      prompt: "Development failed; end the workflow."
     - role: "reviewer"
+      condition: null
+      prompt: "Send the implementation to the reviewer."
   reviewer:
     - role: "developer"
       condition: "rejected"
+      prompt: "Reviewer rejected the implementation; fix the issues."
     - role: "tester"
+      condition: null
+      prompt: "Review passed; run tests on the implementation."
   tester:
     - role: "developer"
       condition: "fixCode"
+      prompt: "Tests found code issues; return to developer."
     - role: "planner"
       condition: "fixSpec"
+      prompt: "Tests found spec issues; return to planner."
     - role: "committer"
+      condition: null
+      prompt: "Tests passed; commit and push the changes."
   committer:
     - role: "developer"
       condition: "hookFailed"
+      prompt: "Push hook failed; return to developer to fix."
     - role: "$END"
+      condition: null
+      prompt: "Commit succeeded; complete the workflow."

docs/builtin-agent-research.md

@@ -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

examples/analyze-topic.yaml

@@ -36,6 +36,8 @@ graph:
   $START:
     - role: "analyst"
       condition: null
+      prompt: "Analyze the topic in the task and produce a structured summary with key points."
   analyst:
     - role: "$END"
       condition: null
+      prompt: "Analysis complete. Finish the workflow."

examples/solve-issue.yaml

@@ -62,14 +62,19 @@ graph:
   $START:
     - role: "planner"
       condition: null
+      prompt: "Analyze the issue described in the task and produce a detailed implementation plan."
   planner:
     - role: "developer"
       condition: null
+      prompt: "Implement the plan from the planner. Write code, tests, and ensure existing tests pass."
   developer:
     - role: "reviewer"
       condition: null
+      prompt: "Review the developer's implementation against the plan for correctness and quality."
   reviewer:
     - role: "developer"
       condition: "notApproved"
+      prompt: "The reviewer rejected your implementation. Read their feedback and fix the issues."
     - role: "$END"
       condition: null
+      prompt: "The review passed. Complete the workflow."

package.json

@@ -15,10 +15,12 @@
     "release": "bun run build && bun test && node scripts/publish-all.mjs"
   },
   "devDependencies": {
+    "@agentclientprotocol/sdk": "^0.22.1",
     "@biomejs/biome": "^2.4.14",
     "@changesets/cli": "^2.31.0",
     "@types/node": "^25.7.0",
     "@types/xxhashjs": "^0.2.4",
+    "@uncaged/workflow-agent-hermes": "workspace:*",
     "bun-types": "^1.3.13"
   }
 }

packages/cli-workflow/src/__tests__/log.test.ts

@@ -0,0 +1,181 @@
+import { mkdir, readdir, rm, writeFile } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, beforeEach, describe, expect, test } from "vitest";
+import { cmdLogClean, cmdLogList, cmdLogShow } from "../commands/log.js";
+
+let storageRoot: string;
+
+beforeEach(async () => {
+  storageRoot = join(tmpdir(), `uwf-log-test-${Date.now()}-${Math.random().toString(36).slice(2)}`);
+  await mkdir(join(storageRoot, "logs"), { recursive: true });
+});
+
+afterEach(async () => {
+  await rm(storageRoot, { recursive: true, force: true });
+});
+
+const entry1 = JSON.stringify({
+  ts: "2026-05-20T10:00:00.000Z",
+  pid: "1716200000000-1234",
+  tag: "W9F3RK2M",
+  msg: "process start",
+  thread: "01J1234ABCDEF",
+  workflow: "solve-issue",
+});
+
+const entry2 = JSON.stringify({
+  ts: "2026-05-20T10:00:01.000Z",
+  pid: "1716200000000-1234",
+  tag: "ABC12345",
+  msg: "step executed",
+  thread: "01J1234ABCDEF",
+  workflow: "solve-issue",
+});
+
+const entry3 = JSON.stringify({
+  ts: "2026-05-20T10:00:02.000Z",
+  pid: "1716200000000-5678",
+  tag: "XYZ98765",
+  msg: "different process",
+  thread: "01JOTHER000000",
+  workflow: "review-code",
+});
+
+const oldEntry = JSON.stringify({
+  ts: "2026-05-19T08:00:00.000Z",
+  pid: "1716200000000-9999",
+  tag: "OLD1TAG1",
+  msg: "old entry",
+  thread: "01JOLD0000000",
+  workflow: "solve-issue",
+});
+
+const olderEntry = JSON.stringify({
+  ts: "2026-05-18T08:00:00.000Z",
+  pid: "1716200000000-0001",
+  tag: "OLD2TAG2",
+  msg: "older entry",
+  thread: "01JOLDER00000",
+  workflow: "review-code",
+});
+
+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");
+}
+
+describe("cmdLogList", () => {
+  test("lists log files with sizes sorted by date descending", async () => {
+    await writeLogFiles();
+    const result = await cmdLogList(storageRoot);
+    expect(result).toHaveLength(3);
+    expect(result[0].name).toBe("2026-05-20.jsonl");
+    expect(result[0].date).toBe("2026-05-20");
+    expect(result[0].size).toBeGreaterThan(0);
+    expect(result[1].name).toBe("2026-05-19.jsonl");
+    expect(result[2].name).toBe("2026-05-18.jsonl");
+  });
+
+  test("returns empty array when no log files exist", async () => {
+    const result = await cmdLogList(storageRoot);
+    expect(result).toEqual([]);
+  });
+
+  test("returns empty array when logs directory does not exist", async () => {
+    const noLogsRoot = join(storageRoot, "nonexistent");
+    await mkdir(noLogsRoot, { recursive: true });
+    const result = await cmdLogList(noLogsRoot);
+    expect(result).toEqual([]);
+  });
+});
+
+describe("cmdLogShow", () => {
+  test("filters by thread ID", async () => {
+    await writeLogFiles();
+    const result = await cmdLogShow(storageRoot, {
+      thread: "01J1234ABCDEF",
+      process: null,
+      date: null,
+    });
+    expect(result).toHaveLength(2);
+    expect(result.every((e) => e.thread === "01J1234ABCDEF")).toBe(true);
+  });
+
+  test("filters by process ID", async () => {
+    await writeLogFiles();
+    const result = await cmdLogShow(storageRoot, {
+      thread: null,
+      process: "1716200000000-1234",
+      date: null,
+    });
+    expect(result).toHaveLength(2);
+    expect(result.every((e) => e.pid === "1716200000000-1234")).toBe(true);
+  });
+
+  test("filters by date", async () => {
+    await writeLogFiles();
+    const result = await cmdLogShow(storageRoot, {
+      thread: null,
+      process: null,
+      date: "2026-05-19",
+    });
+    expect(result).toHaveLength(1);
+    expect(result[0].msg).toBe("old entry");
+  });
+
+  test("reads all files when no date filter", async () => {
+    await writeLogFiles();
+    const result = await cmdLogShow(storageRoot, { thread: null, process: null, date: null });
+    expect(result).toHaveLength(5);
+    // sorted by ts ascending
+    expect(result[0].ts).toBe("2026-05-18T08:00:00.000Z");
+    expect(result[4].ts).toBe("2026-05-20T10:00:02.000Z");
+  });
+
+  test("returns empty when no matches", async () => {
+    await writeLogFiles();
+    const result = await cmdLogShow(storageRoot, {
+      thread: "NONEXISTENT",
+      process: null,
+      date: null,
+    });
+    expect(result).toEqual([]);
+  });
+
+  test("combined thread + date filter", async () => {
+    await writeLogFiles();
+    const result = await cmdLogShow(storageRoot, {
+      thread: "01J1234ABCDEF",
+      process: null,
+      date: "2026-05-20",
+    });
+    expect(result).toHaveLength(2);
+    expect(result.every((e) => e.thread === "01J1234ABCDEF")).toBe(true);
+  });
+});
+
+describe("cmdLogClean", () => {
+  test("deletes files before given date", async () => {
+    await writeLogFiles();
+    const result = await cmdLogClean(storageRoot, "2026-05-20");
+    expect(result.deleted).toBe(2);
+    const remaining = await readdir(join(storageRoot, "logs"));
+    expect(remaining).toEqual(["2026-05-20.jsonl"]);
+  });
+
+  test("deletes nothing when all files are newer", async () => {
+    await writeLogFiles();
+    const result = await cmdLogClean(storageRoot, "2026-05-18");
+    expect(result.deleted).toBe(0);
+  });
+
+  test("handles missing logs directory gracefully", async () => {
+    const noLogsRoot = join(storageRoot, "nonexistent");
+    await mkdir(noLogsRoot, { recursive: true });
+    const result = await cmdLogClean(noLogsRoot, "2026-05-20");
+    expect(result).toEqual({ deleted: 0 });
+  });
+});

packages/cli-workflow/src/cli.ts

@@ -14,6 +14,7 @@ import {
   cmdCasSchemaList,
   cmdCasWalk,
 } from "./commands/cas.js";
+import { cmdLogClean, cmdLogList, cmdLogShow } from "./commands/log.js";
 import { cmdSetup, cmdSetupInteractive } from "./commands/setup.js";
 import { cmdSkillCli } from "./commands/skill.js";
 import {
@@ -379,6 +380,55 @@ casSchema
     });
   });
 
+const log = program.command("log").description("Process-level debug logs");
+
+log
+  .command("list")
+  .description("List log files with sizes")
+  .action(() => {
+    const storageRoot = resolveStorageRoot();
+    runAction(async () => {
+      const result = await cmdLogList(storageRoot);
+      writeOutput(result);
+    });
+  });
+
+log
+  .command("show")
+  .description("Show and filter log entries")
+  .option("--thread <thread-id>", "Filter by thread ID")
+  .option("--process <pid>", "Filter by process ID")
+  .option("--date <date>", "Filter by date (YYYY-MM-DD)")
+  .action(
+    (opts: {
+      thread: string | undefined;
+      process: string | undefined;
+      date: string | undefined;
+    }) => {
+      const storageRoot = resolveStorageRoot();
+      runAction(async () => {
+        const result = await cmdLogShow(storageRoot, {
+          thread: opts.thread ?? null,
+          process: opts.process ?? null,
+          date: opts.date ?? null,
+        });
+        writeOutput(result);
+      });
+    },
+  );
+
+log
+  .command("clean")
+  .description("Delete log files older than given date")
+  .requiredOption("--before <date>", "Delete files before this date (YYYY-MM-DD)")
+  .action((opts: { before: string }) => {
+    const storageRoot = resolveStorageRoot();
+    runAction(async () => {
+      const result = await cmdLogClean(storageRoot, opts.before);
+      writeOutput(result);
+    });
+  });
+
 program.parseAsync(process.argv).catch((e: unknown) => {
   const message = e instanceof Error ? e.message : String(e);
   process.stderr.write(`${message}\n`);

packages/cli-workflow/src/commands/log.ts

@@ -0,0 +1,116 @@
+import { readdir, readFile, stat, unlink } from "node:fs/promises";
+import { join } from "node:path";
+
+type LogListItem = {
+  name: string;
+  size: number;
+  date: string;
+};
+
+type LogShowFilter = {
+  thread: string | null;
+  process: string | null;
+  date: string | null;
+};
+
+type LogEntry = {
+  ts: string;
+  pid: string;
+  tag: string;
+  msg: string;
+  thread: string | null;
+  workflow: string | null;
+};
+
+type LogCleanResult = {
+  deleted: number;
+};
+
+function logsDir(storageRoot: string): string {
+  return join(storageRoot, "logs");
+}
+
+async function listLogFiles(dir: string): Promise<Array<string>> {
+  try {
+    const files = await readdir(dir);
+    return files.filter((f) => f.endsWith(".jsonl")).sort();
+  } catch {
+    return [];
+  }
+}
+
+function dateFromFilename(name: string): string {
+  return name.replace(".jsonl", "");
+}
+
+async function parseJsonlFile(path: string): Promise<Array<LogEntry>> {
+  const content = await readFile(path, "utf-8");
+  const lines = content
+    .trim()
+    .split("\n")
+    .filter((l) => l.length > 0);
+  return lines.map((line) => JSON.parse(line) as LogEntry);
+}
+
+export async function cmdLogList(storageRoot: string): Promise<Array<LogListItem>> {
+  const dir = logsDir(storageRoot);
+  const files = await listLogFiles(dir);
+  const items: Array<LogListItem> = [];
+  for (const name of files) {
+    const s = await stat(join(dir, name));
+    items.push({ name, size: s.size, date: dateFromFilename(name) });
+  }
+  // sort by date descending
+  items.sort((a, b) => (a.date > b.date ? -1 : a.date < b.date ? 1 : 0));
+  return items;
+}
+
+export async function cmdLogShow(
+  storageRoot: string,
+  filter: LogShowFilter,
+): Promise<Array<LogEntry>> {
+  const dir = logsDir(storageRoot);
+  let files: Array<string>;
+
+  if (filter.date !== null) {
+    files = [`${filter.date}.jsonl`];
+  } else {
+    files = await listLogFiles(dir);
+  }
+
+  let entries: Array<LogEntry> = [];
+  for (const file of files) {
+    try {
+      const parsed = await parseJsonlFile(join(dir, file));
+      entries = entries.concat(parsed);
+    } catch {
+      // file doesn't exist or is unreadable, skip
+    }
+  }
+
+  if (filter.thread !== null) {
+    entries = entries.filter((e) => e.thread === filter.thread);
+  }
+  if (filter.process !== null) {
+    entries = entries.filter((e) => e.pid === filter.process);
+  }
+
+  entries.sort((a, b) => (a.ts < b.ts ? -1 : a.ts > b.ts ? 1 : 0));
+  return entries;
+}
+
+export async function cmdLogClean(storageRoot: string, before: string): Promise<LogCleanResult> {
+  const dir = logsDir(storageRoot);
+  const files = await listLogFiles(dir);
+  let deleted = 0;
+
+  for (const name of files) {
+    const date = dateFromFilename(name);
+    if (date < before) {
+      await unlink(join(dir, name));
+      deleted++;
+    }
+  }
+
+  return { deleted };
+}

packages/cli-workflow/src/commands/thread.ts

@@ -23,7 +23,7 @@ import type {
   WorkflowConfig,
   WorkflowPayload,
 } from "@uncaged/workflow-protocol";
-import { generateUlid } from "@uncaged/workflow-util";
+import { createProcessLogger, generateUlid, type ProcessLogger } from "@uncaged/workflow-util";
 import { config as loadDotenv } from "dotenv";
 import { parse, stringify } from "yaml";
 
@@ -47,6 +47,18 @@ import { materializeWorkflowPayload } from "./workflow.js";
 const END_ROLE = "$END";
 export const THREAD_READ_DEFAULT_QUOTA = 4000;
 
+const PL_THREAD_START = "7HNQ4B2X";
+const PL_MODERATOR = "M3K8V9T1";
+const PL_AGENT_SPAWN = "R5J2W8N4";
+const PL_AGENT_DONE = "C6P9E3H7";
+const PL_THREAD_ARCHIVED = "F4D8Q2K5";
+const PL_STEP_ERROR = "B8T5N1V6";
+
+function failStep(plog: ProcessLogger, message: string): never {
+  plog.log(PL_STEP_ERROR, message, null);
+  fail(message);
+}
+
 type ChainState = {
   startHash: CasRef;
   start: StartNodePayload;
@@ -168,6 +180,10 @@ export async function cmdThreadStart(
   const workflowHash = await resolveWorkflowCasRef(uwf, storageRoot, workflowId, projectRoot);
 
   const threadId = generateUlid(Date.now()) as ThreadId;
+  const plog = createProcessLogger({
+    storageRoot,
+    context: { thread: threadId, workflow: workflowHash },
+  });
   const startPayload: StartNodePayload = {
     workflow: workflowHash,
     prompt,
@@ -183,6 +199,12 @@ export async function cmdThreadStart(
   index[threadId] = headHash;
   await saveThreadsIndex(storageRoot, index);
 
+  plog.log(
+    PL_THREAD_START,
+    `thread created workflow=${workflowHash} thread=${threadId} head=${headHash}`,
+    null,
+  );
+
   return { workflow: workflowHash, thread: threadId };
 }
 
@@ -624,13 +646,20 @@ function resolveAgentConfig(
   return agentConfig;
 }
 
-function spawnAgent(agent: AgentConfig, threadId: ThreadId, role: string): CasRef {
+function spawnAgent(
+  plog: ProcessLogger,
+  agent: AgentConfig,
+  threadId: ThreadId,
+  role: string,
+  edgePrompt: string,
+): CasRef {
   const argv = [...agent.args, threadId, role];
+  const env = { ...process.env, UWF_EDGE_PROMPT: edgePrompt };
   let stdout: string;
   try {
     stdout = execFileSync(agent.command, argv, {
       encoding: "utf8",
-      env: process.env,
+      env,
       stdio: ["ignore", "pipe", "pipe"],
     });
   } catch (e) {
@@ -642,12 +671,12 @@ function spawnAgent(agent: AgentConfig, threadId: ThreadId, role: string): CasRe
           ? err.stderr
           : err.stderr.toString("utf8");
     const detail = stderr.trim() !== "" ? `: ${stderr.trim()}` : "";
-    fail(`agent command failed (${agent.command})${detail}`);
+    failStep(plog, `agent command failed (${agent.command})${detail}`);
   }
 
   const line = stdout.trim().split("\n").pop()?.trim() ?? "";
   if (!isCasRef(line)) {
-    fail(`agent stdout is not a valid CAS hash: ${line || "(empty)"}`);
+    failStep(plog, `agent stdout is not a valid CAS hash: ${line || "(empty)"}`);
   }
   return line;
 }
@@ -679,9 +708,15 @@ export async function cmdThreadStep(
     fail(`--count must be a positive integer, got: ${count}`);
   }
 
+  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);
+    const result = await cmdThreadStepOnce(storageRoot, threadId, agentOverride, plog);
     results.push(result);
     if (result.done) {
       break;
@@ -690,16 +725,31 @@ export async function cmdThreadStep(
   return results;
 }
 
-async function cmdThreadStepOnce(
+async function resolveActiveThreadWorkflowHash(
   storageRoot: string,
   threadId: ThreadId,
-  agentOverride: string | null,
-): Promise<StepOutput> {
+): Promise<CasRef> {
   const index = await loadThreadsIndex(storageRoot);
   const headHash = index[threadId];
   if (headHash === undefined) {
     fail(`thread not active: ${threadId}`);
   }
+  const uwf = await createUwfStore(storageRoot);
+  const chain = walkChain(uwf, headHash);
+  return chain.start.workflow;
+}
+
+async function cmdThreadStepOnce(
+  storageRoot: string,
+  threadId: ThreadId,
+  agentOverride: string | null,
+  plog: ProcessLogger,
+): Promise<StepOutput> {
+  const index = await loadThreadsIndex(storageRoot);
+  const headHash = index[threadId];
+  if (headHash === undefined) {
+    failStep(plog, `thread not active: ${threadId}`);
+  }
 
   const uwf = await createUwfStore(storageRoot);
   const chain = walkChain(uwf, headHash);
@@ -709,10 +759,17 @@ async function cmdThreadStepOnce(
 
   const nextResult = await evaluate(workflow, context);
   if (!nextResult.ok) {
-    fail(nextResult.error.message);
+    failStep(plog, `moderator evaluate failed: ${nextResult.error.message}`);
   }
 
-  if (nextResult.value === END_ROLE) {
+  plog.log(
+    PL_MODERATOR,
+    `moderator role=${nextResult.value.role} prompt=${nextResult.value.prompt}`,
+    null,
+  );
+
+  if (nextResult.value.role === END_ROLE) {
+    plog.log(PL_THREAD_ARCHIVED, `thread archived head=${headHash}`, null);
     await archiveThread(storageRoot, threadId, workflowHash, headHash);
     return {
       workflow: workflowHash,
@@ -722,18 +779,25 @@ async function cmdThreadStepOnce(
     };
   }
 
-  const role = nextResult.value;
+  const role = nextResult.value.role;
+  const edgePrompt = nextResult.value.prompt;
   const config = await loadWorkflowConfig(storageRoot);
   const agent = resolveAgentConfig(config, workflow, role, agentOverride);
 
+  plog.log(PL_AGENT_SPAWN, `spawning agent command=${agent.command}`, {
+    args: [...agent.args, threadId, role].join(" "),
+  });
+
   loadDotenv({ path: getEnvPath(storageRoot) });
-  const newHead = spawnAgent(agent, threadId, role);
+  const newHead = spawnAgent(plog, agent, threadId, role, edgePrompt);
+
+  plog.log(PL_AGENT_DONE, `agent returned head=${newHead}`, null);
 
   // Re-create store to pick up nodes written by the agent subprocess
   const uwfAfter = await createUwfStore(storageRoot);
   const newNode = uwfAfter.store.get(newHead);
   if (newNode === null || newNode.type !== uwfAfter.schemas.stepNode) {
-    fail(`agent returned hash that is not a StepNode: ${newHead}`);
+    failStep(plog, `agent returned hash that is not a StepNode: ${newHead}`);
   }
 
   // Reload threads index to avoid overwriting changes made by the agent subprocess
@@ -745,11 +809,12 @@ async function cmdThreadStepOnce(
   const contextAfter = buildModeratorContext(uwfAfter, chainAfter);
   const afterResult = await evaluate(workflow, contextAfter);
   if (!afterResult.ok) {
-    fail(afterResult.error.message);
+    failStep(plog, `post-step moderator evaluate failed: ${afterResult.error.message}`);
   }
 
-  const done = afterResult.value === END_ROLE;
+  const done = afterResult.value.role === END_ROLE;
   if (done) {
+    plog.log(PL_THREAD_ARCHIVED, `thread archived head=${newHead}`, null);
     await archiveThread(storageRoot, threadId, workflowHash, newHead);
   }
 

packages/cli-workflow/src/commands/workflow.ts

@@ -55,10 +55,16 @@ function isJsonSchema(value: unknown): value is JSONSchema {
 function normalizeGraph(graph: Record<string, Transition[]>): Record<string, Transition[]> {
   const result: Record<string, Transition[]> = {};
   for (const [node, transitions] of Object.entries(graph)) {
-    result[node] = transitions.map((t) => ({
-      role: t.role,
-      condition: t.condition ?? null,
-    }));
+    result[node] = transitions.map((t) => {
+      if (typeof t.prompt !== "string" || t.prompt.trim() === "") {
+        fail(`graph[${node}] transition to "${t.role}": prompt is required (non-empty string)`);
+      }
+      return {
+        role: t.role,
+        condition: t.condition ?? null,
+        prompt: t.prompt,
+      };
+    });
   }
   return result;
 }

packages/cli-workflow/src/validate.ts

@@ -44,6 +44,8 @@ function isTransition(value: unknown): boolean {
   const condition = value.condition;
   return (
     typeof value.role === "string" &&
+    typeof value.prompt === "string" &&
+    value.prompt.trim() !== "" &&
     (condition === null || condition === undefined || typeof condition === "string")
   );
 }

packages/workflow-agent-builtin/__tests__/llm-parse.test.ts

@@ -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" });
+  });
+});

packages/workflow-agent-builtin/__tests__/path.test.ts

@@ -0,0 +1,43 @@
+import { describe, expect, test } from "bun:test";
+import { resolve } from "node:path";
+import { resolvePath, resolvePathInWorkspace } 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"));
+  });
+});
+
+describe("resolvePathInWorkspace", () => {
+  test("allows relative paths within workspace", () => {
+    const resolved = resolvePathInWorkspace("/workspace", "src/foo.ts");
+    expect(resolved).toBe(resolve("/workspace", "src/foo.ts"));
+  });
+
+  test("rejects path that escapes workspace root", () => {
+    const resolved = resolvePathInWorkspace("/workspace", "../etc/passwd");
+    expect(resolved).toBeNull();
+  });
+
+  test("rejects absolute path escape via double-dot", () => {
+    const resolved = resolvePathInWorkspace("/workspace/project", "../../outside");
+    expect(resolved).toBeNull();
+  });
+
+  test("allows deep nested path", () => {
+    const resolved = resolvePathInWorkspace("/workspace", "a/b/c/file.txt");
+    expect(resolved).toBe(resolve("/workspace", "a/b/c/file.txt"));
+  });
+});

packages/workflow-agent-builtin/__tests__/prompt.test.ts

@@ -0,0 +1,59 @@
+import { describe, expect, test } from "bun:test";
+
+import type { AgentContext } from "@uncaged/workflow-agent-kit";
+
+import { buildBuiltinPrompt } 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",
+      roles: {
+        developer: {
+          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---",
+    ...overrides,
+  };
+}
+
+describe("buildBuiltinPrompt", () => {
+  test("includes output format, task, and role goal", () => {
+    const prompt = buildBuiltinPrompt(minimalContext());
+    expect(prompt).toContain("status: done");
+    expect(prompt).toContain("## Goal");
+    expect(prompt).toContain("Ship the fix");
+    expect(prompt).toContain("## Task");
+    expect(prompt).toContain("Fix the bug");
+  });
+
+  test("includes history when steps exist", () => {
+    const prompt = buildBuiltinPrompt(
+      minimalContext({
+        steps: [
+          {
+            role: "planner",
+            output: { plan: "step 1" },
+            agent: "uwf-builtin",
+            detail: "detail-hash",
+          },
+        ],
+      }),
+    );
+    expect(prompt).toContain("## Previous Steps");
+    expect(prompt).toContain("planner");
+  });
+});

packages/workflow-agent-builtin/package.json

@@ -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"
+  }
+}

packages/workflow-agent-builtin/src/agent.ts

@@ -0,0 +1,123 @@
+import type { Store } from "@uncaged/json-cas";
+import {
+  type AgentContext,
+  type AgentRunResult,
+  createAgent,
+  loadWorkflowConfig,
+  resolveModel,
+  resolveStorageRoot,
+} from "@uncaged/workflow-agent-kit";
+import { 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 { buildBuiltinPrompt } from "./prompt.js";
+import type { BuiltinSessionState } from "./types.js";
+
+const sessions = new Map<string, BuiltinSessionState>();
+
+function getSession(sessionId: string): BuiltinSessionState {
+  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: BuiltinSessionState,
+  store: Store,
+  maxTurns: number,
+): Promise<AgentRunResult> {
+  const loopResult = await runBuiltinLoop({
+    provider,
+    messages,
+    toolCtx: buildToolContext(storageRoot),
+    maxTurns,
+    existingTurns: session.turns,
+  });
+
+  session.messages = loopResult.messages;
+  session.turns = loopResult.turns;
+
+  const { detailHash, output } = await storeBuiltinDetail(
+    store,
+    session.sessionId,
+    session.model,
+    session.startedAtMs,
+    session.turns,
+  );
+
+  const finalOutput = output !== "" ? output : loopResult.finalText;
+  return { output: finalOutput, 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());
+  const systemPrompt = buildBuiltinPrompt(ctx);
+  const messages: ChatMessage[] = [{ role: "system", content: systemPrompt }];
+
+  const session: BuiltinSessionState = {
+    sessionId,
+    model: provider.model,
+    startedAtMs: Date.now(),
+    messages,
+    turns: [],
+  };
+  sessions.set(sessionId, session);
+
+  return runBuiltinWithMessages(
+    storageRoot,
+    provider,
+    messages,
+    session,
+    ctx.store,
+    BUILTIN_MAX_TURNS,
+  );
+}
+
+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,
+  );
+}
+
+/** Agent CLI factory: built-in LLM loop with file/shell tools. */
+export function createBuiltinAgent(): () => Promise<void> {
+  return createAgent({
+    name: "builtin",
+    run: runBuiltin,
+    continue: continueBuiltin,
+  });
+}

packages/workflow-agent-builtin/src/cli.ts

@@ -0,0 +1,6 @@
+#!/usr/bin/env bun
+
+import { createBuiltinAgent } from "./agent.js";
+
+const main = createBuiltinAgent();
+void main();

packages/workflow-agent-builtin/src/detail.ts

@@ -0,0 +1,115 @@
+import { bootstrap, putSchema, type Store } from "@uncaged/json-cas";
+
+import { BUILTIN_DETAIL_SCHEMA, BUILTIN_TURN_SCHEMA } from "./schemas.js";
+import type {
+  BuiltinDetailPayload,
+  BuiltinLoopTurn,
+  BuiltinToolCall,
+  BuiltinTurnPayload,
+  BuiltinTurnRole,
+} from "./types.js";
+
+function mapToolCalls(calls: NonNullable<BuiltinLoopTurn["toolCalls"]>): BuiltinToolCall[] {
+  return calls.map((call) => ({
+    name: call.name,
+    args: call.args,
+  }));
+}
+
+function loopTurnToAssistantPayload(turn: BuiltinLoopTurn, index: number): BuiltinTurnPayload {
+  return {
+    index,
+    role: "assistant",
+    content: turn.assistantContent ?? "",
+    toolCalls:
+      turn.toolCalls !== null && turn.toolCalls.length > 0 ? mapToolCalls(turn.toolCalls) : null,
+    reasoning: null,
+  };
+}
+
+function loopTurnToToolPayloads(turn: BuiltinLoopTurn, startIndex: number): BuiltinTurnPayload[] {
+  if (turn.toolResults === null || turn.toolResults.length === 0) {
+    return [];
+  }
+  const payloads: BuiltinTurnPayload[] = [];
+  let index = startIndex;
+  for (const result of turn.toolResults) {
+    payloads.push({
+      index,
+      role: "tool" as BuiltinTurnRole,
+      content: result.content,
+      toolCalls: null,
+      reasoning: null,
+    });
+    index += 1;
+  }
+  return payloads;
+}
+
+/** Last assistant message with non-empty text. */
+export function extractFinalAssistantText(turns: BuiltinLoopTurn[]): string {
+  for (let i = turns.length - 1; i >= 0; i--) {
+    const turn = turns[i];
+    if (turn === undefined) {
+      continue;
+    }
+    const text = turn.assistantContent;
+    if (text !== null && text.trim() !== "") {
+      return text;
+    }
+  }
+  return "";
+}
+
+type BuiltinSchemaHashes = {
+  turn: string;
+  detail: string;
+};
+
+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 };
+}
+
+export async function storeBuiltinDetail(
+  store: Store,
+  sessionId: string,
+  model: string,
+  startedAtMs: number,
+  turns: BuiltinLoopTurn[],
+  nowMs: number = Date.now(),
+): Promise<{ detailHash: string; output: string }> {
+  const schemas = await registerBuiltinSchemas(store);
+  const turnHashes: string[] = [];
+  let turnIndex = 0;
+
+  for (const loopTurn of turns) {
+    const assistant = loopTurnToAssistantPayload(loopTurn, turnIndex);
+    const assistantHash = await store.put(schemas.turn, assistant);
+    turnHashes.push(assistantHash);
+    turnIndex += 1;
+
+    const toolPayloads = loopTurnToToolPayloads(loopTurn, turnIndex);
+    for (const toolPayload of toolPayloads) {
+      const toolHash = await store.put(schemas.turn, toolPayload);
+      turnHashes.push(toolHash);
+      turnIndex += 1;
+    }
+  }
+
+  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);
+  const output = extractFinalAssistantText(turns);
+  return { detailHash, output };
+}

packages/workflow-agent-builtin/src/index.ts

@@ -0,0 +1,14 @@
+export { createBuiltinAgent } from "./agent.js";
+export { extractFinalAssistantText, 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 { buildBuiltinPrompt } from "./prompt.js";
+export type { BuiltinTool, ToolContext } from "./tools/index.js";
+export { executeBuiltinTool, getBuiltinTools } from "./tools/index.js";
+export type {
+  BuiltinDetailPayload,
+  BuiltinLoopTurn,
+  BuiltinSessionState,
+  BuiltinTurnPayload,
+} from "./types.js";

packages/workflow-agent-builtin/src/llm/index.ts

@@ -0,0 +1,7 @@
+export { chatCompletionWithTools } from "./llm.js";
+export type {
+  ChatMessage,
+  LlmAssistantResponse,
+  LlmToolCall,
+  OpenAiToolDefinition,
+} from "./types.js";

packages/workflow-agent-builtin/src/llm/llm.ts

@@ -0,0 +1,135 @@
+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[],
+): Promise<LlmAssistantResponse> {
+  let response: Response;
+  try {
+    response = await fetch(chatUrl(provider.baseUrl), {
+      method: "POST",
+      headers: {
+        Authorization: `Bearer ${provider.apiKey}`,
+        "Content-Type": "application/json",
+      },
+      body: JSON.stringify({
+        model: provider.model,
+        messages: messages.map(serializeMessage),
+        tools,
+        tool_choice: "auto",
+      }),
+    });
+  } 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);
+}

packages/workflow-agent-builtin/src/llm/types.ts

@@ -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>;
+  };
+};

packages/workflow-agent-builtin/src/loop.ts

@@ -0,0 +1,110 @@
+import type { ResolvedLlmProvider } from "@uncaged/workflow-agent-kit";
+import { createLogger } from "@uncaged/workflow-util";
+
+import { type ChatMessage, chatCompletionWithTools, type LlmToolCall } from "./llm/index.js";
+import {
+  builtinToolsToOpenAi,
+  executeBuiltinTool,
+  getBuiltinTools,
+  type ToolContext,
+} from "./tools/index.js";
+import type { BuiltinLoopTurn, BuiltinToolCallRecord, BuiltinToolResultRecord } 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;
+  existingTurns: BuiltinLoopTurn[];
+};
+
+export type RunBuiltinLoopResult = {
+  finalText: string;
+  messages: ChatMessage[];
+  turns: BuiltinLoopTurn[];
+};
+
+function mapToolCalls(calls: LlmToolCall[]): BuiltinToolCallRecord[] {
+  return calls.map((call) => ({
+    id: call.id,
+    name: call.name,
+    args: call.arguments,
+  }));
+}
+
+/** Agent run loop: LLM ↔ tools until no tool_calls or maxTurns. */
+export async function runBuiltinLoop(
+  options: RunBuiltinLoopOptions,
+): Promise<RunBuiltinLoopResult> {
+  const messages = [...options.messages];
+  const turns = [...options.existingTurns];
+  const openAiTools = builtinToolsToOpenAi(getBuiltinTools());
+  let finalText = "";
+
+  for (let turn = 0; turn < options.maxTurns; turn++) {
+    log("8K2M4N7P", `builtin loop turn ${turn + 1}/${options.maxTurns}`);
+    const response = await chatCompletionWithTools(options.provider, messages, openAiTools);
+
+    const assistantMessage: ChatMessage = {
+      role: "assistant",
+      content: response.content,
+      tool_calls: response.toolCalls,
+    };
+    messages.push(assistantMessage);
+
+    if (response.toolCalls === null || response.toolCalls.length === 0) {
+      finalText = response.content ?? "";
+      turns.push({
+        assistantContent: response.content,
+        toolCalls: null,
+        toolResults: null,
+      });
+      break;
+    }
+
+    const toolCallRecords = mapToolCalls(response.toolCalls);
+    const toolResults: BuiltinToolResultRecord[] = [];
+
+    for (const call of response.toolCalls) {
+      const result = await executeBuiltinTool(call.name, call.arguments, options.toolCtx);
+      toolResults.push({
+        toolCallId: call.id,
+        name: call.name,
+        content: result,
+      });
+      messages.push({
+        role: "tool",
+        tool_call_id: call.id,
+        content: result,
+      });
+    }
+
+    turns.push({
+      assistantContent: response.content,
+      toolCalls: toolCallRecords,
+      toolResults,
+    });
+  }
+
+  if (finalText === "" && messages.length > 0) {
+    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() !== ""
+      ) {
+        finalText = msg.content;
+        break;
+      }
+    }
+  }
+
+  return { finalText, messages, turns };
+}

packages/workflow-agent-builtin/src/prompt.ts

@@ -0,0 +1,36 @@
+import { type AgentContext, buildRolePrompt } from "@uncaged/workflow-agent-kit";
+
+function buildHistorySummary(steps: AgentContext["steps"]): string {
+  if (steps.length === 0) {
+    return "";
+  }
+
+  const lines: string[] = ["## Previous Steps"];
+  for (let i = 0; i < steps.length; i++) {
+    const step = steps[i];
+    if (step === undefined) {
+      continue;
+    }
+    lines.push("");
+    lines.push(`### Step ${i + 1}: ${step.role}`);
+    lines.push(`Output: ${JSON.stringify(step.output)}`);
+    lines.push(`Agent: ${step.agent}`);
+  }
+  return lines.join("\n");
+}
+
+/** Assemble output format, role prompt, task, and history (aligned with buildHermesPrompt). */
+export function buildBuiltinPrompt(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");
+}

packages/workflow-agent-builtin/src/schemas.ts

@@ -0,0 +1,46 @@
+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: ["index", "role", "content"],
+  properties: {
+    index: { type: "integer" },
+    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,
+};

packages/workflow-agent-builtin/src/tools/index.ts

@@ -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);
+}

packages/workflow-agent-builtin/src/tools/path.ts

@@ -0,0 +1,17 @@
+import { isAbsolute, relative, resolve } from "node:path";
+
+/** Resolve a path relative to the working directory. */
+export function resolvePath(cwd: string, inputPath: string): string {
+  return resolve(cwd, inputPath);
+}
+
+/** Reject paths that escape the workspace root via `..` segments. */
+export function resolvePathInWorkspace(cwd: string, inputPath: string): string | null {
+  const root = resolve(cwd);
+  const target = resolve(root, inputPath);
+  const rel = relative(root, target);
+  if (rel.startsWith("..") || isAbsolute(rel)) {
+    return null;
+  }
+  return target;
+}

packages/workflow-agent-builtin/src/tools/read-file.ts

@@ -0,0 +1,44 @@
+import { readFile, stat } from "node:fs/promises";
+import { resolvePathInWorkspace } 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 = resolvePathInWorkspace(ctx.cwd, args.path);
+    if (resolved === null) {
+      return "Error: path escapes workspace root";
+    }
+    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}`;
+    }
+  },
+};

packages/workflow-agent-builtin/src/tools/run-command.ts

@@ -0,0 +1,103 @@
+import { spawn } from "node:child_process";
+import { resolvePathInWorkspace } 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 in the workspace. Requires UWF_BUILTIN_ALLOW_SHELL=1. Output is truncated.",
+  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 (process.env.UWF_BUILTIN_ALLOW_SHELL !== "1") {
+      return "Error: run_command disabled. Set UWF_BUILTIN_ALLOW_SHELL=1 to enable.";
+    }
+    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";
+      }
+      const resolved = resolvePathInWorkspace(ctx.cwd, args.cwd);
+      if (resolved === null) {
+        return "Error: cwd escapes workspace root";
+      }
+      workDir = resolved;
+    }
+    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}`;
+    }
+  },
+};

packages/workflow-agent-builtin/src/tools/types.ts

@@ -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>;
+};

packages/workflow-agent-builtin/src/tools/write-file.ts

@@ -0,0 +1,39 @@
+import { mkdir, writeFile } from "node:fs/promises";
+import { dirname } from "node:path";
+import { resolvePathInWorkspace } 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 = resolvePathInWorkspace(ctx.cwd, args.path);
+    if (resolved === null) {
+      return "Error: path escapes workspace root";
+    }
+    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}`;
+    }
+  },
+};

packages/workflow-agent-builtin/src/types.ts

@@ -0,0 +1,50 @@
+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 = {
+  index: number;
+  role: BuiltinTurnRole;
+  content: string;
+  toolCalls: BuiltinToolCall[] | null;
+  reasoning: string | null;
+};
+
+export type BuiltinDetailPayload = {
+  sessionId: string;
+  model: string;
+  duration: number;
+  turnCount: number;
+  turns: string[];
+};

packages/workflow-agent-builtin/tsconfig.json

@@ -0,0 +1,9 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "dist"
+  },
+  "include": ["src"],
+  "references": [{ "path": "../workflow-agent-kit" }, { "path": "../workflow-util" }]
+}

packages/workflow-agent-claude-code/__tests__/claude-code.test.ts

@@ -0,0 +1,63 @@
+import { describe, expect, test } from "bun:test";
+import type { AgentContext } from "@uncaged/workflow-agent-kit";
+import type { ThreadId } from "@uncaged/workflow-protocol";
+import { buildClaudeCodePrompt } from "../src/claude-code.js";
+
+function makeCtx(overrides: Partial<AgentContext> = {}): AgentContext {
+  return {
+    threadId: "01JTEST0000000000000000000" as ThreadId,
+    edgePrompt: "Proceed with the assigned role.",
+    isFirstVisit: true,
+    workflow: {
+      roles: {
+        developer: {
+          description: "TDD implementation per test spec",
+          goal: "Write code",
+          capabilities: ["coding"],
+          procedure: "1. Read spec\n2. Write code",
+          output: "List files changed",
+          frontmatter: "",
+        },
+      },
+      conditions: {},
+      graph: {},
+    },
+    role: "developer",
+    start: { prompt: "Fix the bug", workflowHash: "abc123", threadId: "t1" },
+    steps: [],
+    store: {} as AgentContext["store"],
+    outputFormatInstruction: "Use YAML frontmatter",
+    ...overrides,
+  };
+}
+
+describe("buildClaudeCodePrompt", () => {
+  test("assembles outputFormatInstruction + role prompt + task prompt", () => {
+    const result = buildClaudeCodePrompt(makeCtx());
+    expect(result).toMatch(/^Use YAML frontmatter/);
+    expect(result).toContain("Write code");
+    expect(result).toContain("## Task\nFix the bug");
+  });
+
+  test("includes previous steps as history summary", () => {
+    const ctx = makeCtx({
+      steps: [{ role: "planner", output: '{"plan":"do X"}', agent: "hermes" }],
+    });
+    const result = buildClaudeCodePrompt(ctx);
+    expect(result).toContain("## Previous Steps");
+    expect(result).toContain("Step 1: planner");
+    expect(result).toContain("do X");
+  });
+
+  test("omits history section when steps array is empty", () => {
+    const result = buildClaudeCodePrompt(makeCtx({ steps: [] }));
+    expect(result).not.toContain("## Previous Steps");
+  });
+
+  test("works without outputFormatInstruction", () => {
+    const result = buildClaudeCodePrompt(makeCtx({ outputFormatInstruction: "" }));
+    expect(result).not.toMatch(/^\s*\n/);
+    expect(result).toContain("Write code");
+    expect(result).toContain("## Task");
+  });
+});

packages/workflow-agent-claude-code/__tests__/session-detail.test.ts

@@ -0,0 +1,115 @@
+import { describe, expect, test } from "bun:test";
+import { createMemoryStore, walk } from "@uncaged/json-cas";
+import {
+  parseClaudeCodeJsonOutput,
+  storeClaudeCodeDetail,
+  storeClaudeCodeRawOutput,
+} from "../src/session-detail.js";
+import type { ClaudeCodeParsedResult } from "../src/types.js";
+
+describe("parseClaudeCodeJsonOutput", () => {
+  test("parses valid claude -p --output-format json output", () => {
+    const stdout = JSON.stringify({
+      type: "result",
+      subtype: "success",
+      result: "Done fixing bug",
+      session_id: "75e2167f-abc",
+      num_turns: 3,
+      total_cost_usd: 0.08,
+      duration_ms: 10276,
+    });
+    const parsed = parseClaudeCodeJsonOutput(stdout);
+    expect(parsed).not.toBeNull();
+    expect(parsed!.type).toBe("result");
+    expect(parsed!.subtype).toBe("success");
+    expect(parsed!.result).toBe("Done fixing bug");
+    expect(parsed!.sessionId).toBe("75e2167f-abc");
+    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");
+  });
+
+  test("returns null for non-JSON output", () => {
+    const parsed = parseClaudeCodeJsonOutput("Some random text\nwithout JSON");
+    expect(parsed).toBeNull();
+  });
+
+  test("returns null when session_id is missing", () => {
+    const stdout = JSON.stringify({ type: "result", result: "hi", subtype: "success" });
+    const parsed = parseClaudeCodeJsonOutput(stdout);
+    expect(parsed).toBeNull();
+  });
+});
+
+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,
+    };
+
+    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);
+  });
+
+  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 visited: string[] = [];
+    walk(store, detailHash, (hash) => visited.push(hash));
+    expect(visited.length).toBeGreaterThan(0);
+  });
+});
+
+describe("storeClaudeCodeRawOutput", () => {
+  test("stores raw text when JSON parsing fails", async () => {
+    const store = createMemoryStore();
+    const rawText = "Claude produced plain text without JSON";
+    const hash = await storeClaudeCodeRawOutput(store, rawText);
+    expect(hash).toHaveLength(13);
+    const node = await store.get(hash);
+    expect(node).not.toBeNull();
+    expect(node!.payload.text).toBe(rawText);
+  });
+});

packages/workflow-agent-claude-code/package.json

@@ -0,0 +1,33 @@
+{
+  "name": "@uncaged/workflow-agent-claude-code",
+  "version": "0.1.0",
+  "files": [
+    "src",
+    "dist",
+    "package.json"
+  ],
+  "type": "module",
+  "bin": {
+    "uwf-claude-code": "./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:^"
+  },
+  "devDependencies": {
+    "typescript": "^5.8.3"
+  },
+  "publishConfig": {
+    "access": "public"
+  }
+}

packages/workflow-agent-claude-code/src/claude-code.ts

@@ -0,0 +1,148 @@
+import { spawn } from "node:child_process";
+import type { Store } from "@uncaged/json-cas";
+
+import {
+  type AgentContext,
+  type AgentRunResult,
+  buildRolePrompt,
+  createAgent,
+} from "@uncaged/workflow-agent-kit";
+
+import { parseClaudeCodeJsonOutput, storeClaudeCodeDetail } from "./session-detail.js";
+
+const CLAUDE_COMMAND = "claude";
+const CLAUDE_MAX_TURNS = 90;
+
+function buildHistorySummary(steps: AgentContext["steps"]): string {
+  if (steps.length === 0) {
+    return "";
+  }
+
+  const lines: string[] = ["## Previous Steps"];
+  for (let i = 0; i < steps.length; i++) {
+    const step = steps[i];
+    if (step === undefined) {
+      continue;
+    }
+    lines.push("");
+    lines.push(`### Step ${i + 1}: ${step.role}`);
+    lines.push(`Output: ${JSON.stringify(step.output)}`);
+    lines.push(`Agent: ${step.agent}`);
+  }
+  return lines.join("\n");
+}
+
+/** Assemble system prompt, task, and prior step outputs for Claude Code. */
+export function buildClaudeCodePrompt(ctx: AgentContext): string {
+  const roleDef = ctx.workflow.roles[ctx.role];
+  const rolePrompt = roleDef !== undefined ? buildRolePrompt(roleDef) : "";
+  const parts: string[] = [];
+  if (ctx.outputFormatInstruction !== undefined && 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");
+}
+
+function spawnClaude(args: string[]): Promise<{ stdout: string; stderr: string }> {
+  return new Promise((resolve, reject) => {
+    const child = spawn(CLAUDE_COMMAND, args, {
+      env: process.env,
+      shell: false,
+      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();
+    });
+
+    child.on("error", (cause) => {
+      const message = cause instanceof Error ? cause.message : String(cause);
+      reject(new Error(`claude spawn failed: ${message}`));
+    });
+
+    child.on("close", (code) => {
+      if (code === 0) {
+        resolve({ stdout, stderr });
+        return;
+      }
+      const detail = stderr.trim() !== "" ? ` stderr=${stderr.trim()}` : "";
+      reject(new Error(`claude exited with code ${code ?? "null"}${detail}`));
+    });
+  });
+}
+
+function spawnClaudeRun(prompt: string): Promise<{ stdout: string; stderr: string }> {
+  return spawnClaude([
+    "-p",
+    prompt,
+    "--output-format",
+    "json",
+    "--dangerously-skip-permissions",
+    "--max-turns",
+    String(CLAUDE_MAX_TURNS),
+  ]);
+}
+
+function spawnClaudeResume(
+  sessionId: string,
+  message: string,
+): Promise<{ stdout: string; stderr: string }> {
+  return spawnClaude([
+    "-p",
+    message,
+    "--resume",
+    sessionId,
+    "--output-format",
+    "json",
+    "--dangerously-skip-permissions",
+    "--max-turns",
+    String(CLAUDE_MAX_TURNS),
+  ]);
+}
+
+async function processClaudeOutput(stdout: string, store: Store): Promise<AgentRunResult> {
+  const parsed = parseClaudeCodeJsonOutput(stdout);
+
+  if (parsed !== null) {
+    const { detailHash, output, sessionId } = await storeClaudeCodeDetail(store, parsed);
+    return { output, detailHash, sessionId };
+  }
+
+  throw new Error(
+    `Claude Code returned non-JSON output (first 200 chars): ${stdout.slice(0, 200)}`,
+  );
+}
+
+async function runClaudeCode(ctx: AgentContext): Promise<AgentRunResult> {
+  const fullPrompt = buildClaudeCodePrompt(ctx);
+  const { stdout } = await spawnClaudeRun(fullPrompt);
+  return processClaudeOutput(stdout, ctx.store);
+}
+
+async function continueClaudeCode(
+  sessionId: string,
+  message: string,
+  store: Store,
+): Promise<AgentRunResult> {
+  const { stdout } = await spawnClaudeResume(sessionId, message);
+  return processClaudeOutput(stdout, store);
+}
+
+/** Agent CLI factory: parses argv, runs Claude Code, extracts output, writes StepNode. */
+export function createClaudeCodeAgent(): () => Promise<void> {
+  return createAgent({
+    name: "claude-code",
+    run: runClaudeCode,
+    continue: continueClaudeCode,
+  });
+}

packages/workflow-agent-claude-code/src/cli.ts

@@ -0,0 +1,6 @@
+#!/usr/bin/env bun
+
+import { createClaudeCodeAgent } from "./claude-code.js";
+
+const main = createClaudeCodeAgent();
+void main();

packages/workflow-agent-claude-code/src/index.ts

@@ -0,0 +1,6 @@
+export { buildClaudeCodePrompt, createClaudeCodeAgent } from "./claude-code.js";
+export {
+  parseClaudeCodeJsonOutput,
+  storeClaudeCodeDetail,
+  storeClaudeCodeRawOutput,
+} from "./session-detail.js";

packages/workflow-agent-claude-code/src/schemas.ts

@@ -0,0 +1,25 @@
+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"],
+  properties: {
+    sessionId: { type: "string" },
+    numTurns: { type: "integer" },
+    totalCostUsd: { type: "number" },
+    durationMs: { type: "integer" },
+    subtype: { type: "string" },
+  },
+  additionalProperties: false,
+};
+
+export const CLAUDE_CODE_RAW_OUTPUT_SCHEMA: JSONSchema = {
+  title: "claude-code-raw-output",
+  type: "object",
+  required: ["text"],
+  properties: {
+    text: { type: "string" },
+  },
+  additionalProperties: false,
+};

packages/workflow-agent-claude-code/src/session-detail.ts

@@ -0,0 +1,79 @@
+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";
+
+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`). */
+export function parseClaudeCodeJsonOutput(stdout: string): ClaudeCodeParsedResult | null {
+  let parsed: unknown;
+  try {
+    parsed = JSON.parse(stdout.trim());
+  } catch {
+    return null;
+  }
+
+  if (!isRecord(parsed)) {
+    return null;
+  }
+
+  const sessionId = parsed.session_id;
+  const result = parsed.result;
+  const subtype = parsed.subtype;
+
+  if (typeof sessionId !== "string" || typeof result !== "string" || typeof subtype !== "string") {
+    return null;
+  }
+
+  return {
+    type: typeof parsed.type === "string" ? 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,
+  };
+}
+
+type ClaudeCodeSchemaHashes = {
+  detail: string;
+  rawOutput: string;
+};
+
+async function registerSchemas(store: Store): Promise<ClaudeCodeSchemaHashes> {
+  await bootstrap(store);
+  const [detail, rawOutput] = await Promise.all([
+    putSchema(store, CLAUDE_CODE_DETAIL_SCHEMA),
+    putSchema(store, CLAUDE_CODE_RAW_OUTPUT_SCHEMA),
+  ]);
+  return { detail, rawOutput };
+}
+
+/** Store parsed Claude Code result as a CAS detail node. */
+export async function storeClaudeCodeDetail(
+  store: Store,
+  parsed: ClaudeCodeParsedResult,
+): Promise<{ detailHash: string; output: string; sessionId: string }> {
+  const schemas = await registerSchemas(store);
+
+  const detail: ClaudeCodeDetailPayload = {
+    sessionId: parsed.sessionId,
+    numTurns: parsed.numTurns,
+    totalCostUsd: parsed.totalCostUsd,
+    durationMs: parsed.durationMs,
+    subtype: parsed.subtype,
+  };
+
+  const detailHash = await store.put(schemas.detail, detail);
+  return { detailHash, output: parsed.result, sessionId: parsed.sessionId };
+}
+
+/** Fallback: store raw text output when JSON parsing fails. */
+export async function storeClaudeCodeRawOutput(store: Store, rawOutput: string): Promise<string> {
+  const schemas = await registerSchemas(store);
+  return store.put(schemas.rawOutput, { text: rawOutput });
+}

packages/workflow-agent-claude-code/src/types.ts

@@ -0,0 +1,19 @@
+export type ClaudeCodeResultSubtype = "success" | "error_max_turns" | "error_budget";
+
+export type ClaudeCodeParsedResult = {
+  type: string;
+  subtype: ClaudeCodeResultSubtype;
+  result: string;
+  sessionId: string;
+  numTurns: number;
+  totalCostUsd: number;
+  durationMs: number;
+};
+
+export type ClaudeCodeDetailPayload = {
+  sessionId: string;
+  numTurns: number;
+  totalCostUsd: number;
+  durationMs: number;
+  subtype: string;
+};

packages/workflow-agent-claude-code/tsconfig.json

@@ -0,0 +1,6 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": { "rootDir": "src", "outDir": "dist" },
+  "include": ["src"],
+  "references": [{ "path": "../workflow-agent-kit" }]
+}

packages/workflow-agent-hermes/__tests__/acp-client.test.ts

@@ -0,0 +1,77 @@
+import { afterEach, beforeEach, describe, expect, it } from "bun:test";
+
+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("HermesAcpClient", () => {
+  let client: HermesAcpClient;
+
+  beforeEach(() => {
+    client = new HermesAcpClient();
+  });
+
+  afterEach(async () => {
+    await client.close();
+  });
+
+  it(
+    "connect() returns a UUID sessionId",
+    async () => {
+      const sessionId = await client.connect(process.cwd());
+      expect(typeof sessionId).toBe("string");
+      expect(sessionId).toMatch(UUID_RE);
+    },
+    { timeout: 2 * 60 * 1000 },
+  );
+
+  it(
+    "prompt() returns a non-empty text response",
+    async () => {
+      await client.connect(process.cwd());
+      const result = await client.prompt("Reply with exactly the word: PONG");
+      expect(typeof result.text).toBe("string");
+      expect(result.text.length).toBeGreaterThan(0);
+      expect(typeof result.sessionId).toBe("string");
+      expect(result.sessionId).toMatch(UUID_RE);
+    },
+    { timeout: 2 * 60 * 1000 },
+  );
+
+  it(
+    "prompt() can be called twice on the same session (resume)",
+    async () => {
+      await client.connect(process.cwd());
+
+      const first = await client.prompt("Say the word ALPHA and nothing else.");
+      expect(first.text.length).toBeGreaterThan(0);
+
+      const second = await client.prompt("Now say the word BETA and nothing else.");
+      expect(second.text.length).toBeGreaterThan(0);
+
+      expect(first.sessionId).toBe(second.sessionId);
+    },
+    { timeout: 2 * 60 * 1000 },
+  );
+
+  it(
+    "prompt() collects structured messages including tool calls",
+    async () => {
+      await client.connect(process.cwd());
+      const result = await client.prompt("Run this command: echo TOOL_DETAIL_TEST");
+      expect(result.messages.length).toBeGreaterThan(0);
+      // Should have at least one tool message (the echo command)
+      const toolMessages = result.messages.filter((m) => m.role === "tool");
+      expect(toolMessages.length).toBeGreaterThan(0);
+      // Tool message should contain the output
+      const toolContent = toolMessages[0]?.content ?? "";
+      expect(toolContent).toContain("TOOL_DETAIL_TEST");
+      // Should have assistant messages with tool_calls
+      const assistantWithTools = result.messages.filter(
+        (m) => m.role === "assistant" && m.tool_calls !== null,
+      );
+      expect(assistantWithTools.length).toBeGreaterThan(0);
+    },
+    { timeout: 2 * 60 * 1000 },
+  );
+});

packages/workflow-agent-hermes/__tests__/hermes-prompt.test.ts

@@ -0,0 +1,78 @@
+import { describe, expect, test } from "bun:test";
+import type { AgentContext } from "@uncaged/workflow-agent-kit";
+import type { ThreadId } from "@uncaged/workflow-protocol";
+import { buildHermesPrompt } from "../src/hermes.js";
+
+function makeCtx(overrides: Partial<AgentContext> = {}): AgentContext {
+  return {
+    threadId: "01JTEST0000000000000000000" as ThreadId,
+    edgePrompt: "Proceed with the assigned role.",
+    isFirstVisit: true,
+    workflow: {
+      roles: {
+        developer: {
+          description: "TDD implementation per test spec",
+          goal: "Write code",
+          capabilities: ["coding"],
+          procedure: "1. Read spec\n2. Write code",
+          output: "List files changed",
+          frontmatter: "",
+        },
+      },
+      conditions: {},
+      graph: {},
+    },
+    role: "developer",
+    start: { prompt: "Fix the bug", workflowHash: "abc123", threadId: "t1" },
+    steps: [],
+    store: {} as AgentContext["store"],
+    outputFormatInstruction: "Use YAML frontmatter",
+    ...overrides,
+  };
+}
+
+describe("buildHermesPrompt", () => {
+  test("first visit uses full role prompt and includes moderator instruction", () => {
+    const result = buildHermesPrompt(
+      makeCtx({ edgePrompt: "Focus on the failing test.", isFirstVisit: true }),
+    );
+
+    expect(result).toMatch(/^Use YAML frontmatter/);
+    expect(result).toContain("Write code");
+    expect(result).toContain("## Task\nFix the bug");
+    expect(result).toContain("## Moderator Instruction");
+    expect(result).toContain("Focus on the failing test.");
+  });
+
+  test("re-entry uses continuation prompt with edge instruction", () => {
+    const ctx = makeCtx({
+      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" },
+      ],
+    });
+
+    const result = buildHermesPrompt(ctx);
+
+    expect(result).not.toContain("## Task");
+    expect(result).toContain("## What Happened Since Your Last Turn");
+    expect(result).toContain("## Moderator Instruction");
+    expect(result).toContain("The reviewer rejected your work.");
+  });
+
+  test("forced first visit via isFirstVisit uses initial prompt even when role appears in history", () => {
+    const result = buildHermesPrompt(
+      makeCtx({
+        isFirstVisit: true,
+        steps: [{ role: "developer", output: { done: true }, agent: "uwf-hermes" }],
+        edgePrompt: "Retry with a fresh approach.",
+      }),
+    );
+
+    expect(result).toContain("## Task");
+    expect(result).toContain("Retry with a fresh approach.");
+    expect(result).not.toContain("## What Happened Since Your Last Turn");
+  });
+});

packages/workflow-agent-hermes/__tests__/resume-e2e.test.ts

@@ -0,0 +1,56 @@
+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;
+  });
+
+  it(
+    "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 },
+  );
+});

packages/workflow-agent-hermes/package.json

@@ -22,7 +22,9 @@
   },
   "dependencies": {
     "@uncaged/json-cas": "^0.4.0",
-    "@uncaged/workflow-agent-kit": "workspace:^"
+    "@uncaged/workflow-agent-kit": "workspace:^",
+    "@uncaged/workflow-protocol": "workspace:^",
+    "@uncaged/workflow-util": "workspace:^"
   },
   "devDependencies": {
     "typescript": "^5.8.3"

packages/workflow-agent-hermes/src/acp-client.ts

@@ -0,0 +1,393 @@
+import type { ChildProcess } from "node:child_process";
+import { spawn } from "node:child_process";
+import { createInterface } from "node:readline";
+
+import type { HermesSessionMessage } from "./types.js";
+
+const HERMES_COMMAND = "hermes";
+const PROTOCOL_VERSION = 1;
+
+type JsonRpcResponse = {
+  jsonrpc: "2.0";
+  id: number;
+  result?: unknown;
+  error?: { code: number; message: string };
+};
+
+type PendingRequest = {
+  resolve: (value: JsonRpcResponse) => void;
+  reject: (reason: Error) => void;
+};
+
+/** Tracks in-flight tool calls so we can build complete messages when they finish. */
+type PendingToolCall = {
+  name: string;
+  args: string;
+};
+
+export type AcpPromptResult = {
+  text: string;
+  sessionId: string;
+  messages: HermesSessionMessage[];
+};
+
+export class HermesAcpClient {
+  private process: ChildProcess | null = null;
+  private nextId = 1;
+  private sessionId: string | null = null;
+  private stderrBuffer = "";
+  private pending = new Map<number, PendingRequest>();
+
+  // Message collection state
+  private messageChunks: string[] = [];
+  private reasoningChunks: string[] = [];
+  private pendingTools = new Map<string, PendingToolCall>();
+  messages: HermesSessionMessage[] = [];
+
+  /** Spawn hermes acp, initialize, create session */
+  async connect(cwd: string): Promise<string> {
+    await this.ensureProcess();
+    await this.initialize();
+
+    const sessionResponse = (await this.sendRequest("session/new", {
+      cwd,
+      mcpServers: [],
+    })) as { result: { sessionId: string } };
+
+    const sessionId = sessionResponse.result?.sessionId;
+    if (typeof sessionId !== "string" || sessionId === "") {
+      throw new Error(`session/new did not return a sessionId: ${JSON.stringify(sessionResponse)}`);
+    }
+
+    this.sessionId = sessionId;
+    return sessionId;
+  }
+
+  /** Spawn hermes acp, initialize, resume an existing session */
+  async resume(sessionId: string, cwd: string): Promise<string> {
+    await this.ensureProcess();
+    await this.initialize();
+
+    const response = await this.sendRequest("session/resume", {
+      cwd,
+      sessionId,
+      mcpServers: [],
+    });
+
+    if ((response as { error?: unknown }).error !== undefined) {
+      throw new Error(
+        `session/resume failed: ${JSON.stringify((response as { error: unknown }).error)}`,
+      );
+    }
+
+    this.sessionId = sessionId;
+    return sessionId;
+  }
+
+  /** Send prompt and collect full response text + structured messages. */
+  async prompt(text: string): Promise<AcpPromptResult> {
+    if (this.sessionId === null) {
+      throw new Error("Not connected — call connect() first");
+    }
+
+    this.messageChunks = [];
+    this.reasoningChunks = [];
+
+    const response = await this.sendRequest("session/prompt", {
+      sessionId: this.sessionId,
+      prompt: [{ type: "text", text }],
+    });
+
+    if ((response as { error?: unknown }).error !== undefined) {
+      throw new Error(
+        `session/prompt failed: ${JSON.stringify((response as { error: unknown }).error)}`,
+      );
+    }
+
+    // Flush any trailing assistant text that wasn't followed by a tool call.
+    this.flushAssistantMessage();
+
+    // Extract the final assistant text from collected messages.
+    let finalText = "";
+    for (let i = this.messages.length - 1; i >= 0; i--) {
+      const msg = this.messages[i];
+      if (
+        msg !== undefined &&
+        msg.role === "assistant" &&
+        msg.content !== null &&
+        msg.content.trim() !== ""
+      ) {
+        finalText = msg.content;
+        break;
+      }
+    }
+
+    return {
+      text: finalText,
+      sessionId: this.sessionId,
+      messages: this.messages,
+    };
+  }
+
+  /** Close the connection */
+  async close(): Promise<void> {
+    if (this.process === null) {
+      return;
+    }
+    this.sessionId = null;
+    this.process.stdin?.end();
+    const proc = this.process;
+    await new Promise<void>((resolve) => {
+      proc.on("close", () => resolve());
+      setTimeout(resolve, 5000);
+    });
+    this.process = null;
+  }
+
+  // ---- JSON-RPC transport ----
+
+  private sendRequest(
+    method: string,
+    params: Record<string, unknown>,
+    timeoutMs = 10 * 60 * 1000,
+  ): Promise<JsonRpcResponse> {
+    const id = this.nextId++;
+    return new Promise<JsonRpcResponse>((resolve, reject) => {
+      const timer = setTimeout(() => {
+        this.pending.delete(id);
+        reject(new Error(`Timeout waiting for response to ${method} (id=${id})`));
+      }, timeoutMs);
+
+      this.pending.set(id, {
+        resolve: (value) => {
+          clearTimeout(timer);
+          resolve(value);
+        },
+        reject: (err) => {
+          clearTimeout(timer);
+          reject(err);
+        },
+      });
+
+      this.writeLine(JSON.stringify({ jsonrpc: "2.0", id, method, params }));
+    });
+  }
+
+  private sendNotification(method: string, params?: Record<string, unknown>): void {
+    const message: Record<string, unknown> = { jsonrpc: "2.0", method };
+    if (params !== undefined) {
+      message.params = params;
+    }
+    this.writeLine(JSON.stringify(message));
+  }
+
+  private writeLine(line: string): void {
+    if (this.process?.stdin === null || this.process?.stdin === undefined) {
+      throw new Error("Cannot write: hermes acp process stdin not available");
+    }
+    this.process.stdin.write(`${line}\n`);
+  }
+
+  private handleLine(line: string): void {
+    if (line === "") {
+      return;
+    }
+
+    let parsed: unknown;
+    try {
+      parsed = JSON.parse(line);
+    } catch {
+      return;
+    }
+
+    const msg = parsed as Record<string, unknown>;
+
+    const hasId = "id" in msg && msg.id !== undefined && msg.id !== null;
+    const hasMethod = typeof msg.method === "string";
+
+    // JSON-RPC response to one of our requests (has "id" but no "method")
+    if (hasId && !hasMethod) {
+      const response = msg as unknown as JsonRpcResponse;
+      const handler = this.pending.get(response.id);
+      if (handler !== undefined) {
+        this.pending.delete(response.id);
+        handler.resolve(response);
+      }
+      return;
+    }
+
+    // Server-initiated JSON-RPC request: session/request_permission (has "id" + "method")
+    if (msg.method === "session/request_permission" && hasId) {
+      const params = msg.params as Record<string, unknown> | undefined;
+      const options = (params?.options ?? []) as Array<{ optionId?: string }>;
+      const firstOptionId = options[0]?.optionId ?? "";
+      this.writeLine(
+        JSON.stringify({
+          jsonrpc: "2.0",
+          id: msg.id,
+          result: { outcome: { outcome: "selected", optionId: firstOptionId } },
+        }),
+      );
+      return;
+    }
+
+    // JSON-RPC notification — session/update (no "id")
+    if (msg.method === "session/update") {
+      const params = msg.params as Record<string, unknown> | undefined;
+      const update = params?.update as Record<string, unknown> | undefined;
+      if (update !== undefined) {
+        this.handleSessionUpdate(update);
+      }
+      return;
+    }
+  }
+
+  // ---- 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);
+        }
+        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);
+        }
+        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();
+        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);
+        }
+        break;
+      }
+
+      default:
+        break;
+    }
+  }
+
+  /** Flush any accumulated text/reasoning into an assistant message. */
+  private flushAssistantMessage(): void {
+    const text = this.messageChunks.join("");
+    const reasoning = this.reasoningChunks.join("");
+    if (text !== "" || reasoning !== "") {
+      this.messages.push({
+        role: "assistant",
+        content: text || null,
+        reasoning: reasoning || null,
+        tool_calls: null,
+      });
+    }
+    this.messageChunks = [];
+    this.reasoningChunks = [];
+  }
+
+  private rejectAll(err: Error): void {
+    for (const handler of this.pending.values()) {
+      handler.reject(err);
+    }
+    this.pending.clear();
+  }
+
+  private async ensureProcess(): Promise<void> {
+    if (this.process !== null) {
+      return;
+    }
+
+    const child = spawn(HERMES_COMMAND, ["acp"], {
+      env: process.env,
+      shell: false,
+      stdio: ["pipe", "pipe", "pipe"],
+    });
+
+    this.process = child;
+
+    child.stderr?.on("data", (chunk: Buffer) => {
+      this.stderrBuffer += chunk.toString();
+    });
+
+    child.on("error", (cause) => {
+      const message = cause instanceof Error ? cause.message : String(cause);
+      this.rejectAll(new Error(`hermes acp spawn failed: ${message}`));
+    });
+
+    child.on("close", (code) => {
+      if (code !== 0 && this.pending.size > 0) {
+        const detail = this.stderrBuffer.trim() !== "" ? ` stderr=${this.stderrBuffer.trim()}` : "";
+        this.rejectAll(
+          new Error(`hermes acp exited unexpectedly with code ${code ?? "null"}${detail}`),
+        );
+      }
+    });
+
+    if (child.stdout === null) {
+      throw new Error("hermes acp process stdout is not available");
+    }
+    const rl = createInterface({ input: child.stdout });
+    rl.on("line", (line) => {
+      this.handleLine(line.trim());
+    });
+  }
+
+  private async initialize(): Promise<void> {
+    const initResponse = await this.sendRequest("initialize", {
+      protocolVersion: PROTOCOL_VERSION,
+      clientInfo: { name: "uwf", version: "0.1.0" },
+      capabilities: {},
+    });
+
+    if ((initResponse as { error?: unknown }).error !== undefined) {
+      throw new Error(
+        `initialize failed: ${JSON.stringify((initResponse as { error: unknown }).error)}`,
+      );
+    }
+
+    this.sendNotification("initialized");
+  }
+}

packages/workflow-agent-hermes/src/hermes.ts

@@ -1,21 +1,18 @@
-import { spawn } from "node:child_process";
 import type { Store } from "@uncaged/json-cas";
-
 import {
   type AgentContext,
   type AgentRunResult,
+  buildContinuationPrompt,
   buildRolePrompt,
   createAgent,
 } from "@uncaged/workflow-agent-kit";
+import { createLogger } from "@uncaged/workflow-util";
 
-import {
-  loadHermesSession,
-  parseSessionIdFromStdout,
-  storeHermesSessionDetail,
-} from "./session-detail.js";
+import { HermesAcpClient } from "./acp-client.js";
+import { getCachedSessionId, isResumeDisabled, setCachedSessionId } from "./session-cache.js";
+import { storeHermesSessionDetail } from "./session-detail.js";
 
-const HERMES_COMMAND = "hermes";
-const HERMES_MAX_TURNS = 90;
+const log = createLogger({ sink: { kind: "stderr" } });
 
 function buildHistorySummary(steps: AgentContext["steps"]): string {
   if (steps.length === 0) {
@@ -36,12 +33,11 @@ function buildHistorySummary(steps: AgentContext["steps"]): string {
   return lines.join("\n");
 }
 
-/** Assemble system prompt, task, and prior step outputs for Hermes. */
-export function buildHermesPrompt(ctx: AgentContext): string {
+function buildInitialPrompt(ctx: AgentContext): string {
   const roleDef = ctx.workflow.roles[ctx.role];
   const rolePrompt = roleDef !== undefined ? buildRolePrompt(roleDef) : "";
   const parts: string[] = [];
-  if (ctx.outputFormatInstruction !== undefined && ctx.outputFormatInstruction !== "") {
+  if (ctx.outputFormatInstruction !== "") {
     parts.push(ctx.outputFormatInstruction, "");
   }
   parts.push(rolePrompt, "", "## Task", ctx.start.prompt);
@@ -49,116 +45,145 @@ export function buildHermesPrompt(ctx: AgentContext): string {
   if (historyBlock !== "") {
     parts.push("", historyBlock);
   }
+  parts.push("", "## Moderator Instruction", "", ctx.edgePrompt);
   return parts.join("\n");
 }
 
-function spawnHermes(args: string[]): Promise<{ stdout: string; stderr: string }> {
-  return new Promise((resolve, reject) => {
-    const child = spawn(HERMES_COMMAND, args, {
-      env: process.env,
-      shell: false,
-      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();
-    });
-
-    child.on("error", (cause) => {
-      const message = cause instanceof Error ? cause.message : String(cause);
-      reject(new Error(`hermes spawn failed: ${message}`));
-    });
-
-    child.on("close", (code) => {
-      if (code === 0) {
-        resolve({ stdout, stderr });
-        return;
-      }
-      const detail = stderr.trim() !== "" ? ` stderr=${stderr.trim()}` : "";
-      reject(new Error(`hermes exited with code ${code ?? "null"}${detail}`));
-    });
-  });
-}
-
-function spawnHermesChat(prompt: string): Promise<{ stdout: string; stderr: string }> {
-  return spawnHermes([
-    "chat",
-    "-q",
-    prompt,
-    "--yolo",
-    "--max-turns",
-    String(HERMES_MAX_TURNS),
-    "--quiet",
-  ]);
-}
-
-function spawnHermesResume(
-  sessionId: string,
-  message: string,
-): Promise<{ stdout: string; stderr: string }> {
-  return spawnHermes([
-    "chat",
-    "--resume",
-    sessionId,
-    "-q",
-    message,
-    "--yolo",
-    "--max-turns",
-    String(HERMES_MAX_TURNS),
-    "--quiet",
-  ]);
-}
-
-function parseSessionId(stdout: string, stderr: string): string {
-  const sessionId = parseSessionIdFromStdout(stderr) ?? parseSessionIdFromStdout(stdout);
-  if (sessionId === null) {
-    throw new Error(
-      "Failed to parse session_id from hermes output.\n" +
-        `stderr (first 200 chars): ${stderr.slice(0, 200)}\n` +
-        `stdout (first 200 chars): ${stdout.slice(0, 200)}`,
-    );
+/** Assemble system prompt, task, and prior step outputs for Hermes. */
+export function buildHermesPrompt(ctx: AgentContext): string {
+  if (!ctx.isFirstVisit) {
+    const parts: string[] = [];
+    if (ctx.outputFormatInstruction !== "") {
+      parts.push(ctx.outputFormatInstruction, "");
+    }
+    parts.push(buildContinuationPrompt(ctx.steps, ctx.role, ctx.edgePrompt));
+    return parts.join("\n");
   }
-  return sessionId;
+
+  return buildInitialPrompt(ctx);
 }
 
-async function buildResultFromSession(sessionId: string, store: Store): Promise<AgentRunResult> {
-  const session = await loadHermesSession(sessionId);
-  if (session === null) {
-    throw new Error(`Failed to load hermes session file for session_id: ${sessionId}`);
-  }
-  const { detailHash, output } = await storeHermesSessionDetail(store, session);
-  return { output, detailHash, sessionId };
-}
-
-async function runHermes(ctx: AgentContext): Promise<AgentRunResult> {
-  const fullPrompt = buildHermesPrompt(ctx);
-  const { stdout, stderr } = await spawnHermesChat(fullPrompt);
-  const sessionId = parseSessionId(stdout, stderr);
-  return buildResultFromSession(sessionId, ctx.store);
-}
-
-async function continueHermes(
-  sessionId: string,
-  message: string,
+async function storePromptResult(
   store: Store,
-): Promise<AgentRunResult> {
-  const { stdout, stderr } = await spawnHermesResume(sessionId, message);
-  // Resume may return a new session_id
-  const newSessionId = parseSessionIdFromStdout(stderr) ?? parseSessionIdFromStdout(stdout);
-  const resolvedId = newSessionId ?? sessionId;
-  return buildResultFromSession(resolvedId, store);
+  sessionId: string,
+  messages: Awaited<ReturnType<HermesAcpClient["prompt"]>>["messages"],
+): Promise<{ detailHash: string }> {
+  const session = {
+    session_id: sessionId,
+    model: "",
+    session_start: new Date().toISOString(),
+    messages,
+  };
+  return storeHermesSessionDetail(store, session);
 }
 
-/** Agent CLI factory: parses argv, runs Hermes, extracts output, writes StepNode. */
+type PromptAttempt = {
+  useContinuation: boolean;
+  resumed: boolean;
+};
+
+async function prepareSession(
+  client: HermesAcpClient,
+  ctx: AgentContext,
+  cwd: string,
+): Promise<PromptAttempt> {
+  if (ctx.isFirstVisit || isResumeDisabled()) {
+    await client.connect(cwd);
+    return { useContinuation: false, resumed: false };
+  }
+
+  const cachedSessionId = await getCachedSessionId(ctx.threadId, ctx.role);
+  if (cachedSessionId === null) {
+    log("6RWK3N8Q", `no cached session for ${ctx.threadId}:${ctx.role}, starting new session`);
+    await client.connect(cwd);
+    return { useContinuation: false, resumed: false };
+  }
+
+  try {
+    await client.resume(cachedSessionId, cwd);
+    log("9MHT4V2P", `resumed hermes session ${cachedSessionId} for ${ctx.threadId}:${ctx.role}`);
+    return { useContinuation: true, resumed: true };
+  } catch (error) {
+    const message = error instanceof Error ? error.message : String(error);
+    log("3XPN7K4W", `session resume failed, falling back to new session: ${message}`);
+    await client.close();
+    await client.connect(cwd);
+    return { useContinuation: false, resumed: false };
+  }
+}
+
+/**
+ * Agent CLI factory: parses argv, runs Hermes, extracts output, writes StepNode.
+ *
+ * A single ACP client is shared across run() and continue() calls so that
+ * frontmatter retry loops keep the same Hermes session context.  The client
+ * is closed once the agent process exits (via process.on("exit")).
+ */
 export function createHermesAgent(): () => Promise<void> {
-  return createAgent({
+  const client = new HermesAcpClient();
+
+  // Ensure cleanup regardless of how the process exits.
+  process.on("exit", () => {
+    void client.close();
+  });
+
+  async function runPrompt(ctx: AgentContext, useContinuation: boolean): Promise<AgentRunResult> {
+    const effectiveCtx = useContinuation ? ctx : { ...ctx, isFirstVisit: true };
+    const fullPrompt = buildHermesPrompt(effectiveCtx);
+    const { text, sessionId, messages } = await client.prompt(fullPrompt);
+    const { detailHash } = await storePromptResult(ctx.store, sessionId, messages);
+
+    if (!isResumeDisabled()) {
+      await setCachedSessionId(ctx.threadId, ctx.role, sessionId);
+    }
+
+    return { output: text, detailHash, sessionId };
+  }
+
+  async function runHermes(ctx: AgentContext): Promise<AgentRunResult> {
+    const cwd = process.cwd();
+    const attempt = await prepareSession(client, ctx, cwd);
+
+    try {
+      return await runPrompt(ctx, attempt.useContinuation);
+    } catch (error) {
+      if (!attempt.resumed) {
+        throw error;
+      }
+
+      const message = error instanceof Error ? error.message : String(error);
+      log("8FQW2R6N", `continuation prompt failed, retrying with initial prompt: ${message}`);
+      await client.close();
+      await client.connect(cwd);
+      return runPrompt(ctx, false);
+    }
+  }
+
+  async function continueHermes(
+    _sessionId: string,
+    message: string,
+    store: Store,
+  ): Promise<AgentRunResult> {
+    // Client is already connected from runHermes — same ACP session,
+    // so the agent sees the full conversation history (crucial for retries).
+    const { text, sessionId, messages } = await client.prompt(message);
+    const { detailHash } = await storePromptResult(store, sessionId, messages);
+    return { output: text, detailHash, sessionId };
+  }
+
+  const agentMain = createAgent({
     name: "hermes",
     run: runHermes,
     continue: continueHermes,
   });
+
+  // Wrap to ensure ACP client is closed after agent completes,
+  // so the hermes subprocess exits and bun can terminate.
+  return async () => {
+    try {
+      await agentMain();
+    } finally {
+      await client.close();
+    }
+  };
 }

packages/workflow-agent-hermes/src/index.ts

@@ -1 +1,2 @@
+export { HermesAcpClient } from "./acp-client.js";
 export { buildHermesPrompt, createHermesAgent } from "./hermes.js";

packages/workflow-agent-hermes/src/session-cache.ts

@@ -0,0 +1,70 @@
+import { mkdir, readFile, writeFile } from "node:fs/promises";
+import { dirname, join } from "node:path";
+
+import { resolveStorageRoot } 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;
+}
+
+export async function setCachedSessionId(
+  threadId: ThreadId,
+  role: string,
+  sessionId: string,
+): Promise<void> {
+  const cache = await readCache();
+  cache[cacheKey(threadId, role)] = sessionId;
+  await writeCache(cache);
+}

packages/workflow-agent-kit/__tests__/build-continuation-prompt.test.ts

@@ -0,0 +1,70 @@
+import type { StepContext } from "@uncaged/workflow-protocol";
+import { describe, expect, test } from "vitest";
+import { buildContinuationPrompt } from "../src/build-continuation-prompt.js";
+
+const reviewerStep: StepContext = {
+  role: "reviewer",
+  output: { approved: false, comments: "Missing tests" },
+  detail: "2MXBG6PN4A8JR",
+  agent: "uwf-hermes",
+};
+
+const developerStep: StepContext = {
+  role: "developer",
+  output: { filesChanged: ["src/app.ts"], summary: "Initial fix" },
+  detail: "1VPBG9SM5E7WK",
+  agent: "uwf-hermes",
+};
+
+describe("buildContinuationPrompt", () => {
+  test("includes steps after the last matching role and the edge prompt", () => {
+    const steps: StepContext[] = [
+      developerStep,
+      reviewerStep,
+      {
+        role: "planner",
+        output: { plan: "revise approach" },
+        detail: "7BQST3VW9F2MA",
+        agent: "uwf-hermes",
+      },
+    ];
+
+    const result = buildContinuationPrompt(
+      steps,
+      "developer",
+      "The reviewer rejected your implementation. Read their feedback and fix the issues.",
+    );
+
+    expect(result).toContain("## What Happened Since Your Last Turn");
+    expect(result).toContain("### Step 2: reviewer");
+    expect(result).toContain("Missing tests");
+    expect(result).toContain("### Step 3: planner");
+    expect(result).toContain("## Moderator Instruction");
+    expect(result).toContain("The reviewer rejected your implementation.");
+    expect(result).not.toContain("Initial fix");
+  });
+
+  test("uses all steps when the role has not run before", () => {
+    const result = buildContinuationPrompt(
+      [developerStep, reviewerStep],
+      "planner",
+      "Continue from the reviewer feedback.",
+    );
+
+    expect(result).toContain("### Step 1: developer");
+    expect(result).toContain("### Step 2: reviewer");
+    expect(result).toContain("Continue from the reviewer feedback.");
+  });
+
+  test("still includes moderator instruction when there are no intervening steps", () => {
+    const result = buildContinuationPrompt(
+      [developerStep],
+      "developer",
+      "Please revise your work.",
+    );
+
+    expect(result).not.toContain("## What Happened Since Your Last Turn");
+    expect(result).toContain("## Moderator Instruction");
+    expect(result).toContain("Please revise your work.");
+  });
+});

packages/workflow-agent-kit/src/build-continuation-prompt.ts

@@ -0,0 +1,53 @@
+import type { StepContext } from "@uncaged/workflow-protocol";
+
+function formatStep(step: StepContext, stepNumber: number): string {
+  return [
+    `### Step ${stepNumber}: ${step.role}`,
+    `Output: ${JSON.stringify(step.output)}`,
+    `Agent: ${step.agent}`,
+  ].join("\n");
+}
+
+function findLastRoleIndex(steps: StepContext[], role: string): number {
+  for (let i = steps.length - 1; i >= 0; i--) {
+    const step = steps[i];
+    if (step !== undefined && step.role === role) {
+      return i;
+    }
+  }
+  return -1;
+}
+
+/**
+ * Build a continuation prompt for a role re-entry.
+ *
+ * Finds the most recent step for `role`, collects everything after it as context,
+ * and appends the moderator edge prompt as the instruction.
+ */
+export function buildContinuationPrompt(
+  steps: StepContext[],
+  role: string,
+  edgePrompt: string,
+): string {
+  const lastIndex = findLastRoleIndex(steps, role);
+  const sinceSteps = lastIndex >= 0 ? steps.slice(lastIndex + 1) : steps;
+
+  const parts: string[] = [];
+
+  if (sinceSteps.length > 0) {
+    parts.push("## What Happened Since Your Last Turn");
+    const baseStepNumber = lastIndex >= 0 ? lastIndex + 2 : 1;
+    for (let i = 0; i < sinceSteps.length; i++) {
+      const step = sinceSteps[i];
+      if (step === undefined) {
+        continue;
+      }
+      parts.push("");
+      parts.push(formatStep(step, baseStepNumber + i));
+    }
+    parts.push("");
+  }
+
+  parts.push("## Moderator Instruction", "", edgePrompt);
+  return parts.join("\n");
+}

packages/workflow-agent-kit/src/context.ts

@@ -21,6 +21,14 @@ 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) {
@@ -133,6 +141,8 @@ 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 {
     threadId,
@@ -142,6 +152,8 @@ export async function buildContext(threadId: ThreadId, role: string): Promise<Ag
     workflow,
     store,
     outputFormatInstruction: "",
+    edgePrompt,
+    isFirstVisit,
   };
 }
 
@@ -178,6 +190,8 @@ export async function buildContextWithMeta(
   }
 
   const steps = await buildHistory(store, chain.stepsNewestFirst);
+  const edgePrompt = readEdgePrompt();
+  const isFirstVisit = !steps.some((s) => s.role === role);
 
   return {
     threadId,
@@ -187,6 +201,8 @@ export async function buildContextWithMeta(
     workflow,
     store,
     outputFormatInstruction: "",
+    edgePrompt,
+    isFirstVisit,
     meta: { storageRoot, store, schemas, headHash, chain },
   };
 }

packages/workflow-agent-kit/src/index.ts

@@ -1,3 +1,4 @@
+export { buildContinuationPrompt } from "./build-continuation-prompt.js";
 export { buildOutputFormatInstruction } from "./build-output-format-instruction.js";
 export { buildRolePrompt } from "./build-role-prompt.js";
 export type { BuildContextMeta } from "./context.js";
@@ -11,7 +12,7 @@ export {
 export type { FrontmatterFastPathResult } from "./frontmatter.js";
 export { tryFrontmatterFastPath } from "./frontmatter.js";
 export { createAgent } from "./run.js";
-export { getConfigPath, getEnvPath, loadWorkflowConfig } from "./storage.js";
+export { getConfigPath, getEnvPath, loadWorkflowConfig, resolveStorageRoot } from "./storage.js";
 export type {
   AgentContext,
   AgentContinueFn,

packages/workflow-agent-kit/src/types.ts

@@ -12,6 +12,15 @@ export type AgentContext = ModeratorContext & {
    * role's output schema.  Populated by `createAgent` at run time.
    */
   outputFormatInstruction: string;
+  /**
+   * Edge prompt from the graph transition that led to this role (UWF_EDGE_PROMPT).
+   * Always the real moderator instruction for this step.
+   */
+  edgePrompt: string;
+  /**
+   * True when the current role has not appeared in steps history before this invocation.
+   */
+  isFirstVisit: boolean;
 };
 
 export type AgentRunResult = {

packages/workflow-dashboard/server/workflow.ts

@@ -77,9 +77,11 @@ function stepsToPayload(name: string, description: string, steps: WorkFlowSteps)
           };
         }
       }
+      const targetRole = t.target === "END" ? "$END" : t.target;
       return {
-        role: t.target === "END" ? "$END" : t.target,
+        role: targetRole,
         condition: condName,
+        prompt: `Transition to ${targetRole}.`,
       };
     });
 
@@ -87,7 +89,14 @@ function stepsToPayload(name: string, description: string, steps: WorkFlowSteps)
   }
 
   if (steps.length > 0) {
-    graph["$START"] = [{ role: steps[0].role.name, condition: null }];
+    const firstRole = steps[0].role.name;
+    graph["$START"] = [
+      {
+        role: firstRole,
+        condition: null,
+        prompt: `Begin workflow at role ${firstRole}.`,
+      },
+    ];
   }
 
   return { name, description, roles, conditions, graph };

packages/workflow-moderator/__tests__/evaluate.test.ts

@@ -9,27 +9,27 @@ const solveIssueWorkflow: WorkflowPayload = {
   roles: {
     planner: {
       description: "Creates implementation plan",
-      identity: "You are a planning agent.",
-      prepare: "Review the issue context.",
-      execute: "Create a step-by-step plan.",
-      report: "Output the plan and steps.",
-      outputSchema: "5GWKR8TN1V3JA",
+      goal: "You are a planning agent.",
+      capabilities: ["planning"],
+      procedure: "Create a step-by-step plan.",
+      output: "Output the plan and steps.",
+      frontmatter: "5GWKR8TN1V3JA",
     },
     developer: {
       description: "Implements code changes",
-      identity: "You are a developer agent.",
-      prepare: "Load coding tools.",
-      execute: "Implement the plan.",
-      report: "List files changed and summary.",
-      outputSchema: "8CNWT4KR6D1HV",
+      goal: "You are a developer agent.",
+      capabilities: ["coding"],
+      procedure: "Implement the plan.",
+      output: "List files changed and summary.",
+      frontmatter: "8CNWT4KR6D1HV",
     },
     reviewer: {
       description: "Reviews code changes",
-      identity: "You are a code reviewer.",
-      prepare: "Review project conventions.",
-      execute: "Review the implementation.",
-      report: "Approve or reject with comments.",
-      outputSchema: "1VPBG9SM5E7WK",
+      goal: "You are a code reviewer.",
+      capabilities: ["code-review"],
+      procedure: "Review the implementation.",
+      output: "Approve or reject with comments.",
+      frontmatter: "1VPBG9SM5E7WK",
     },
   },
   conditions: {
@@ -43,15 +43,35 @@ const solveIssueWorkflow: WorkflowPayload = {
     },
   },
   graph: {
-    $START: [{ role: "planner", condition: null }],
-    planner: [
-      { role: "developer", condition: "needsClarification" },
-      { role: "$END", condition: null },
+    $START: [
+      {
+        role: "planner",
+        condition: null,
+        prompt: "Start planning from the issue in the task.",
+      },
+    ],
+    planner: [
+      {
+        role: "developer",
+        condition: "needsClarification",
+        prompt: "Clarification is needed; hand off to developer.",
+      },
+      { role: "$END", condition: null, prompt: "Planning complete; end workflow." },
+    ],
+    developer: [
+      {
+        role: "reviewer",
+        condition: null,
+        prompt: "Implementation done; send to reviewer.",
+      },
     ],
-    developer: [{ role: "reviewer", condition: null }],
     reviewer: [
-      { role: "developer", condition: "rejected" },
-      { role: "$END", condition: null },
+      {
+        role: "developer",
+        condition: "rejected",
+        prompt: "Reviewer rejected; return to developer.",
+      },
+      { role: "$END", condition: null, prompt: "Review passed; end workflow." },
     ],
   },
 };
@@ -69,7 +89,10 @@ function makeContext(steps: ModeratorContext["steps"]): ModeratorContext {
 describe("evaluate", () => {
   test("$START → first role (fallback)", async () => {
     const result = await evaluate(solveIssueWorkflow, makeContext([]));
-    expect(result).toEqual({ ok: true, value: "planner" });
+    expect(result).toEqual({
+      ok: true,
+      value: { role: "planner", prompt: "Start planning from the issue in the task." },
+    });
   });
 
   test("condition match (rejected → developer)", async () => {
@@ -82,7 +105,10 @@ describe("evaluate", () => {
       },
     ]);
     const result = await evaluate(solveIssueWorkflow, context);
-    expect(result).toEqual({ ok: true, value: "developer" });
+    expect(result).toEqual({
+      ok: true,
+      value: { role: "developer", prompt: "Reviewer rejected; return to developer." },
+    });
   });
 
   test("fallback when condition does not match → $END", async () => {
@@ -95,7 +121,10 @@ describe("evaluate", () => {
       },
     ]);
     const result = await evaluate(solveIssueWorkflow, context);
-    expect(result).toEqual({ ok: true, value: "$END" });
+    expect(result).toEqual({
+      ok: true,
+      value: { role: "$END", prompt: "Review passed; end workflow." },
+    });
   });
 
   test("missing role in graph → error", async () => {
@@ -124,7 +153,10 @@ describe("evaluate", () => {
       },
     ]);
     const result = await evaluate(solveIssueWorkflow, context);
-    expect(result).toEqual({ ok: true, value: "developer" });
+    expect(result).toEqual({
+      ok: true,
+      value: { role: "developer", prompt: "Clarification is needed; hand off to developer." },
+    });
   });
 
   test("$last returns most recent matching role's frontmatter", async () => {
@@ -137,10 +169,20 @@ describe("evaluate", () => {
         },
       },
       graph: {
-        $START: [{ role: "developer", condition: null }],
+        $START: [
+          {
+            role: "developer",
+            condition: null,
+            prompt: "Begin development.",
+          },
+        ],
         developer: [
-          { role: "$END", condition: "devFailed" },
-          { role: "reviewer", condition: null },
+          { role: "$END", condition: "devFailed", prompt: "Development failed; end." },
+          {
+            role: "reviewer",
+            condition: null,
+            prompt: "Development succeeded; review.",
+          },
         ],
       },
     };
@@ -165,7 +207,10 @@ describe("evaluate", () => {
       },
     ]);
     const result = await evaluate(workflow, context);
-    expect(result).toEqual({ ok: true, value: "$END" });
+    expect(result).toEqual({
+      ok: true,
+      value: { role: "$END", prompt: "Development failed; end." },
+    });
   });
 
   test("$first returns earliest matching role's frontmatter", async () => {
@@ -178,10 +223,20 @@ describe("evaluate", () => {
         },
       },
       graph: {
-        $START: [{ role: "planner", condition: null }],
+        $START: [
+          {
+            role: "planner",
+            condition: null,
+            prompt: "Begin planning.",
+          },
+        ],
         planner: [
-          { role: "$END", condition: "firstPlanReady" },
-          { role: "developer", condition: null },
+          { role: "$END", condition: "firstPlanReady", prompt: "First plan was ready; end." },
+          {
+            role: "developer",
+            condition: null,
+            prompt: "Plan not ready on first pass; implement.",
+          },
         ],
       },
     };
@@ -206,7 +261,10 @@ describe("evaluate", () => {
       },
     ]);
     const result = await evaluate(workflow, context);
-    expect(result).toEqual({ ok: true, value: "$END" });
+    expect(result).toEqual({
+      ok: true,
+      value: { role: "$END", prompt: "First plan was ready; end." },
+    });
   });
 
   test("$last returns undefined for unmatched role", async () => {
@@ -219,10 +277,20 @@ describe("evaluate", () => {
         },
       },
       graph: {
-        $START: [{ role: "planner", condition: null }],
+        $START: [
+          {
+            role: "planner",
+            condition: null,
+            prompt: "Begin planning.",
+          },
+        ],
         planner: [
-          { role: "$END", condition: "hasReviewer" },
-          { role: "developer", condition: null },
+          { role: "$END", condition: "hasReviewer", prompt: "Reviewer already ran; end." },
+          {
+            role: "developer",
+            condition: null,
+            prompt: "No reviewer yet; implement.",
+          },
         ],
       },
     };
@@ -236,6 +304,9 @@ describe("evaluate", () => {
     ]);
     const result = await evaluate(workflow, context);
     // no reviewer step → $exists returns false → fallback to developer
-    expect(result).toEqual({ ok: true, value: "developer" });
+    expect(result).toEqual({
+      ok: true,
+      value: { role: "developer", prompt: "No reviewer yet; implement." },
+    });
   });
 });

packages/workflow-moderator/src/evaluate.ts

@@ -1,7 +1,7 @@
 import type { ModeratorContext, WorkflowPayload } from "@uncaged/workflow-protocol";
 import jsonata from "jsonata";
 
-import type { Result } from "./types.js";
+import type { EvaluateResult, Result } from "./types.js";
 
 const START_ROLE = "$START";
 
@@ -78,7 +78,7 @@ function currentRole(context: ModeratorContext): string {
 export async function evaluate(
   workflow: WorkflowPayload,
   context: ModeratorContext,
-): Promise<Result<string, Error>> {
+): Promise<Result<EvaluateResult, Error>> {
   const role = currentRole(context);
   const transitions = workflow.graph[role];
   if (transitions === undefined) {
@@ -90,7 +90,7 @@ export async function evaluate(
 
   for (const transition of transitions) {
     if (transition.condition === null) {
-      return { ok: true, value: transition.role };
+      return { ok: true, value: { role: transition.role, prompt: transition.prompt } };
     }
 
     const conditionDef = workflow.conditions[transition.condition];
@@ -106,7 +106,7 @@ export async function evaluate(
       return evalResult;
     }
     if (isTruthy(evalResult.value)) {
-      return { ok: true, value: transition.role };
+      return { ok: true, value: { role: transition.role, prompt: transition.prompt } };
     }
   }
 

packages/workflow-moderator/src/index.ts

@@ -1 +1,2 @@
 export { evaluate } from "./evaluate.js";
+export type { EvaluateResult } from "./types.js";

packages/workflow-moderator/src/types.ts

@@ -1 +1,7 @@
 export type Result<T, E> = { ok: true; value: T } | { ok: false; error: E };
+
+/** The result of moderator evaluation — which role to go to, and the edge prompt. */
+export type EvaluateResult = {
+  role: string;
+  prompt: string;
+};

packages/workflow-protocol/src/schemas.ts

@@ -26,10 +26,11 @@ const CONDITION_DEFINITION: JSONSchema = {
 
 const TRANSITION: JSONSchema = {
   type: "object",
-  required: ["role", "condition"],
+  required: ["role", "condition", "prompt"],
   properties: {
     role: { type: "string" },
     condition: { anyOf: [{ type: "string" }, { type: "null" }] },
+    prompt: { type: "string" },
   },
   additionalProperties: false,
 };

packages/workflow-protocol/src/types.ts

@@ -28,6 +28,7 @@ export type RoleDefinition = {
 export type Transition = {
   role: string;
   condition: string | null;
+  prompt: string;
 };
 
 export type ConditionDefinition = {

packages/workflow-util/__tests__/process-logger.test.ts

@@ -0,0 +1,81 @@
+import { mkdirSync, mkdtempSync, readFileSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, describe, expect, test } from "bun:test";
+
+import { createProcessLogger } from "../src/process-logger/index.js";
+
+function logDateKey(date: Date): string {
+  return date.toISOString().slice(0, 10);
+}
+
+describe("createProcessLogger", () => {
+  let tmpDir: string;
+
+  afterEach(() => {
+    if (tmpDir !== undefined) {
+      rmSync(tmpDir, { recursive: true, force: true });
+    }
+  });
+
+  test("writes init and log lines to dated JSONL under storage root", () => {
+    tmpDir = mkdtempSync(join(tmpdir(), "uwf-process-log-"));
+    const plog = createProcessLogger({
+      storageRoot: tmpDir,
+      context: { thread: "THREAD01", workflow: "WORKFLOW01" },
+    });
+
+    expect(plog.pid).toMatch(/^\d+-\d+$/);
+
+    plog.log("7NQW4HBT", "moderator selected role=planner", null);
+
+    const logPath = join(tmpDir, "logs", `${logDateKey(new Date())}.jsonl`);
+    const lines = readFileSync(logPath, "utf8")
+      .trim()
+      .split("\n")
+      .map((line) => JSON.parse(line) as Record<string, string>);
+
+    expect(lines).toHaveLength(2);
+    expect(lines[0]?.tag).toBe("W9F3RK2M");
+    expect(lines[0]?.pid).toBe(plog.pid);
+    expect(lines[0]?.thread).toBe("THREAD01");
+    expect(lines[0]?.workflow).toBe("WORKFLOW01");
+    expect(lines[0]?.msg).toContain("process start");
+    expect(lines[0]?.msg).toContain("node=");
+
+    expect(lines[1]?.tag).toBe("7NQW4HBT");
+    expect(lines[1]?.msg).toBe("moderator selected role=planner");
+    expect(lines[1]?.thread).toBe("THREAD01");
+    expect(lines[1]?.workflow).toBe("WORKFLOW01");
+  });
+
+  test("creates logs directory when missing", () => {
+    tmpDir = mkdtempSync(join(tmpdir(), "uwf-process-log-"));
+    createProcessLogger({
+      storageRoot: tmpDir,
+      context: { thread: null, workflow: null },
+    });
+    mkdirSync(join(tmpDir, "logs"), { recursive: true });
+    expect(() =>
+      readFileSync(join(tmpDir, "logs", `${logDateKey(new Date())}.jsonl`), "utf8"),
+    ).not.toThrow();
+  });
+
+  test("merges per-call context into the JSONL entry", () => {
+    tmpDir = mkdtempSync(join(tmpdir(), "uwf-process-log-"));
+    const plog = createProcessLogger({
+      storageRoot: tmpDir,
+      context: { thread: "T1", workflow: null },
+    });
+    plog.log("M3K8V9T1", "spawn agent", { command: "uwf-hermes", args: "tid role" });
+
+    const logPath = join(tmpDir, "logs", `${logDateKey(new Date())}.jsonl`);
+    const lines = readFileSync(logPath, "utf8")
+      .trim()
+      .split("\n")
+      .map((line) => JSON.parse(line) as Record<string, string>);
+    const last = lines[lines.length - 1];
+    expect(last?.command).toBe("uwf-hermes");
+    expect(last?.args).toBe("tid role");
+  });
+});

packages/workflow-util/src/cli-reference.ts

@@ -26,6 +26,7 @@ uwf workflow list                 # list all registered workflows
 uwf thread start <workflow> -p <prompt>           # create a thread (no execution)
 uwf thread step <thread-id>                       # execute one moderator→agent→extract cycle
                [--agent <cmd>]                    # override agent command
+               [-c, --count <number>]             # run multiple steps (default: 1)
 uwf thread show <thread-id>                       # show thread head pointer
 uwf thread list                                   # list active threads
                [--all]                            # include archived threads
@@ -56,6 +57,17 @@ uwf cas schema list               # list all registered schemas
 uwf cas schema get <hash>         # show a schema by its type hash
 \`\`\`
 
+## Log Commands
+
+\`\`\`
+uwf log list                      # list log files with sizes
+uwf log show                      # show all log entries
+           [--thread <thread-id>] # filter by thread ID
+           [--process <pid>]      # filter by process ID
+           [--date <YYYY-MM-DD>]  # filter by date
+uwf log clean --before <date>     # delete log files before given date
+\`\`\`
+
 ## Global Options
 
 \`\`\`
@@ -69,6 +81,7 @@ uwf -V, --version                 # print version
 - **Thread**: A single workflow execution (ULID). State is an immutable CAS chain; active threads are indexed in \`threads.yaml\`.
 - **Step**: One moderator→agent→extract cycle. Run \`uwf thread step\` repeatedly until \`$END\`.
 - **CAS**: Content-Addressed Storage — all nodes are immutable and identified by hash.
-- **Role**: Named actor with goal, capabilities, procedure, output, and meta; the moderator routes between roles.
+- **Role**: Named actor with goal, capabilities, procedure, output, and frontmatter schema; the moderator routes between roles.
+- **Edge Prompt**: Required instruction on each graph edge — the moderator's dispatch message to the agent.
 `;
 }

packages/workflow-util/src/index.ts

@@ -13,6 +13,13 @@ export {
   validateFrontmatter,
 } from "./frontmatter-markdown/index.js";
 export { createLogger } from "./logger.js";
+export { createProcessLogger } from "./process-logger/index.js";
+export type {
+  CreateProcessLoggerOptions,
+  ProcessLogFn,
+  ProcessLogger,
+  ProcessLoggerContext,
+} from "./process-logger/index.js";
 export { normalizeRefsField } from "./refs-field.js";
 export { err, ok } from "./result.js";
 export { getDefaultWorkflowStorageRoot, getGlobalCasDir } from "./storage-root.js";

packages/workflow-util/src/logger.ts

@@ -1,28 +1,8 @@
 import { appendFileSync } from "node:fs";
 
-import { CROCKFORD_BASE32_ALPHABET } from "./base32.js";
+import { assertValidLogTag } from "./process-logger/log-tag.js";
 import type { CreateLoggerOptions, LogFn } from "./types.js";
 
-const TAG_LENGTH = 8;
-
-const TAG_CHAR_SET: ReadonlySet<string> = new Set(CROCKFORD_BASE32_ALPHABET.split(""));
-
-function assertValidLogTag(tag: string): void {
-  if (tag.length !== TAG_LENGTH) {
-    throw new Error(`log tag must be exactly ${TAG_LENGTH} characters`);
-  }
-  for (let i = 0; i < tag.length; i++) {
-    const ch = tag[i];
-    if (ch === undefined) {
-      throw new Error("log tag validation failed");
-    }
-    const upper = ch.toUpperCase();
-    if (!TAG_CHAR_SET.has(upper)) {
-      throw new Error(`invalid Crockford Base32 character in log tag: ${ch}`);
-    }
-  }
-}
-
 /** Append one JSONL log record: `{ tag, content, timestamp }` per RFC-001. */
 export function createLogger(options: CreateLoggerOptions): LogFn {
   if (options.sink.kind === "stderr") {

packages/workflow-util/src/process-logger/index.ts

@@ -0,0 +1,7 @@
+export { createProcessLogger } from "./process-logger.js";
+export type {
+  CreateProcessLoggerOptions,
+  ProcessLogFn,
+  ProcessLogger,
+  ProcessLoggerContext,
+} from "./types.js";

packages/workflow-util/src/process-logger/log-tag.ts

@@ -0,0 +1,21 @@
+import { CROCKFORD_BASE32_ALPHABET } from "../base32.js";
+
+const TAG_LENGTH = 8;
+
+const TAG_CHAR_SET: ReadonlySet<string> = new Set(CROCKFORD_BASE32_ALPHABET.split(""));
+
+export function assertValidLogTag(tag: string): void {
+  if (tag.length !== TAG_LENGTH) {
+    throw new Error(`log tag must be exactly ${TAG_LENGTH} characters`);
+  }
+  for (let i = 0; i < tag.length; i++) {
+    const ch = tag[i];
+    if (ch === undefined) {
+      throw new Error("log tag validation failed");
+    }
+    const upper = ch.toUpperCase();
+    if (!TAG_CHAR_SET.has(upper)) {
+      throw new Error(`invalid Crockford Base32 character in log tag: ${ch}`);
+    }
+  }
+}

packages/workflow-util/src/process-logger/process-logger.ts

@@ -0,0 +1,78 @@
+import { appendFileSync, mkdirSync } from "node:fs";
+import { join } from "node:path";
+
+import { getDefaultWorkflowStorageRoot } from "../storage-root.js";
+import { assertValidLogTag } from "./log-tag.js";
+import type { CreateProcessLoggerOptions, ProcessLogger, ProcessLoggerContext } from "./types.js";
+
+const INIT_TAG = "W9F3RK2M";
+
+function logDateKey(date: Date): string {
+  return date.toISOString().slice(0, 10);
+}
+
+function getProcessLogsDir(storageRoot: string): string {
+  return join(storageRoot, "logs");
+}
+
+function getProcessLogFilePath(storageRoot: string, date: Date): string {
+  return join(getProcessLogsDir(storageRoot), `${logDateKey(date)}.jsonl`);
+}
+
+function buildEntry(
+  processId: string,
+  tag: string,
+  msg: string,
+  baseContext: ProcessLoggerContext,
+  extra: Record<string, string> | null,
+): Record<string, string> {
+  const entry: Record<string, string> = {
+    ts: new Date().toISOString(),
+    pid: processId,
+    tag: tag.toUpperCase(),
+    msg,
+  };
+  if (baseContext.thread !== null) {
+    entry.thread = baseContext.thread;
+  }
+  if (baseContext.workflow !== null) {
+    entry.workflow = baseContext.workflow;
+  }
+  if (extra !== null) {
+    for (const [key, value] of Object.entries(extra)) {
+      entry[key] = value;
+    }
+  }
+  return entry;
+}
+
+function appendEntry(filePath: string, entry: Record<string, string>): void {
+  appendFileSync(filePath, `${JSON.stringify(entry)}\n`, "utf8");
+}
+
+/** Process-scoped debug logger — append-only JSONL under `<storageRoot>/logs/YYYY-MM-DD.jsonl`. */
+export function createProcessLogger(options: CreateProcessLoggerOptions): ProcessLogger {
+  const storageRoot = options.storageRoot ?? getDefaultWorkflowStorageRoot();
+  const processId = `${Date.now()}-${process.pid}`;
+  const baseContext = options.context;
+  const logFilePath = getProcessLogFilePath(storageRoot, new Date());
+
+  mkdirSync(getProcessLogsDir(storageRoot), { recursive: true });
+
+  const log: ProcessLogger["log"] = (tag, msg, context = null) => {
+    assertValidLogTag(tag);
+    appendEntry(logFilePath, buildEntry(processId, tag, msg, baseContext, context));
+  };
+
+  const argvSummary = JSON.stringify(process.argv);
+  const initParts = [`argv=${argvSummary}`, `node=${process.version}`];
+  if (baseContext.thread !== null) {
+    initParts.push(`thread=${baseContext.thread}`);
+  }
+  if (baseContext.workflow !== null) {
+    initParts.push(`workflow=${baseContext.workflow}`);
+  }
+  log(INIT_TAG, `process start ${initParts.join(" ")}`, null);
+
+  return { pid: processId, log };
+}

packages/workflow-util/src/process-logger/types.ts

@@ -0,0 +1,20 @@
+export type ProcessLoggerContext = {
+  thread: string | null;
+  workflow: string | null;
+};
+
+export type CreateProcessLoggerOptions = {
+  storageRoot: string | null;
+  context: ProcessLoggerContext;
+};
+
+export type ProcessLogFn = (
+  tag: string,
+  msg: string,
+  context: Record<string, string> | null,
+) => void;
+
+export type ProcessLogger = {
+  pid: string;
+  log: ProcessLogFn;
+};

scripts/publish-all.mjs

@@ -21,6 +21,7 @@ const publishOrder = [
   "workflow-moderator",
   "workflow-agent-kit",
   "workflow-agent-hermes",
+  "workflow-agent-builtin",
   "cli-workflow",
 ];
 

tsconfig.json

@@ -23,6 +23,7 @@
     { "path": "packages/workflow-moderator" },
     { "path": "packages/workflow-agent-kit" },
     { "path": "packages/workflow-agent-hermes" },
+    { "path": "packages/workflow-agent-builtin" },
     { "path": "packages/cli-workflow" }
   ]
 }