feat: migrate CAS to global storage

- Add getGlobalCasDir() to storage-root.ts
- cmd-cas.ts uses global CAS dir, threadId kept for CLI compat
- thread rm no longer deletes .cas/ directories
- Rename createThreadCas → createCasStore (deprecated alias kept)
- 134 tests passing

BREAKING: CAS moves from <thread>.cas/ to <storageRoot>/cas/

Fixes #30

docs/plans/2025-05-07-workflow-as-agent.md

@@ -0,0 +1,315 @@
+# Workflow-as-Agent Implementation Plan
+
+> **For Hermes:** Use subagent-driven-development skill to implement this plan task-by-task.
+
+**Goal:** Enable workflows to invoke other workflows as agents, backed by global CAS and refs tracking.
+
+**Architecture:** Migrate CAS from thread-local to global (`~/.uncaged/workflow/cas/`), add `refs` to RoleStep for GC traceability, then build `workflowAsAgent(name)` factory that resolves workflow name → bundle via registry and spawns a child thread.
+
+**Tech Stack:** TypeScript, Bun, Zod v4, monorepo with `packages/`
+
+**Issue:** https://git.shazhou.work/uncaged/workflow/issues/25
+
+---
+
+## Phase 1: Global CAS Migration
+
+Move CAS storage from `<threadDir>/<threadId>.cas/` to `~/.uncaged/workflow/cas/` (global, content-addressed, immutable). This is a **breaking change** — thread-local `.cas/` directories are abandoned.
+
+### Task 1.1: Add `globalCasDir` helper to `storage-root.ts`
+
+**Objective:** Provide a single function that returns the global CAS directory path.
+
+**Files:**
+- Modify: `packages/workflow/src/storage-root.ts`
+- Test: `packages/workflow/__tests__/storage-root.test.ts`
+
+**Implementation:**
+
+```typescript
+// storage-root.ts — add export
+export function getGlobalCasDir(storageRoot?: string): string {
+  const root = storageRoot ?? getDefaultWorkflowStorageRoot();
+  return join(root, "cas");
+}
+```
+
+Export from `packages/workflow/src/index.ts`.
+
+### Task 1.2: Update `cmd-cas.ts` to use global CAS
+
+**Objective:** CLI `cas get/put/list/rm` no longer needs threadId for storage location — CAS is global. But keep threadId in CLI for backward compat of planner/coder prompts (they pass threadId).
+
+**Files:**
+- Modify: `packages/cli-workflow/src/cmd-cas.ts`
+
+**Changes:**
+- `resolveCasDir` → use `getGlobalCasDir(storageRoot)` instead of deriving from thread data path
+- `cmdCasPut` / `cmdCasGet` / `cmdCasList` / `cmdCasRm`: threadId is still accepted (prompts pass it) but storage goes to global dir
+- Remove the `resolveThreadDataPath` dependency for CAS operations — thread doesn't need to exist to read CAS
+
+```typescript
+import { createThreadCas, getGlobalCasDir } from "@uncaged/workflow";
+
+export async function cmdCasGet(
+  storageRoot: string,
+  _threadId: string, // kept for CLI compat, not used for path
+  hash: string,
+): Promise<Result<string, string>> {
+  const cas = createThreadCas(getGlobalCasDir(storageRoot));
+  const content = await cas.get(hash);
+  if (content === null) {
+    return err(`cas entry not found: ${hash}`);
+  }
+  return ok(content);
+}
+// ... same pattern for put/list/rm
+```
+
+### Task 1.3: Update `cmd-thread.ts` — thread rm no longer deletes `.cas/`
+
+**Objective:** Since CAS is global, `thread rm` should NOT delete CAS entries. CAS cleanup is GC's job.
+
+**Files:**
+- Modify: `packages/cli-workflow/src/cmd-thread.ts`
+- Check: remove any `rmdir` / `unlink` of `<threadId>.cas/` directory
+
+### Task 1.4: Rename `createThreadCas` → `createCasStore`
+
+**Objective:** The name `createThreadCas` is misleading now. Rename to `createCasStore`.
+
+**Files:**
+- Modify: `packages/workflow/src/cas.ts` — rename function
+- Modify: `packages/workflow/src/index.ts` — update export (keep `createThreadCas` as deprecated alias for one release)
+- Modify: all consumers (`cmd-cas.ts`)
+
+### Task 1.5: Update tests
+
+**Objective:** All CAS-related tests use global dir instead of thread-local.
+
+**Files:**
+- Modify: `packages/cli-workflow/__tests__/commands.test.ts`
+- Verify: `bun test` passes
+
+### Task 1.6: Clean up old thread-local `.cas/` references
+
+**Objective:** Remove dead code that creates/reads thread-local `.cas/` directories.
+
+**Files:**
+- Search all `*.ts` for `.cas` path construction patterns
+- Remove orphaned helpers
+
+---
+
+## Phase 2: RoleStep `refs` Tracking
+
+Add `refs: string[]` to persisted role steps so GC can trace which CAS entries are alive.
+
+### Task 2.1: Add `refs` to `RoleOutput` and engine persistence
+
+**Objective:** Every role step can declare which CAS hashes it produced or consumed.
+
+**Files:**
+- Modify: `packages/workflow/src/types.ts`
+- Modify: `packages/workflow/src/engine.ts`
+
+**Changes to `types.ts`:**
+
+```typescript
+export type RoleOutput = {
+  role: string;
+  content: string;
+  meta: Record<string, unknown>;
+  refs: string[];  // CAS hashes produced/consumed by this step
+};
+```
+
+**Changes to `engine.ts`:**
+- `appendDataLine` for role steps: include `refs` field (default `[]` if not provided)
+
+### Task 2.2: Auto-populate refs from meta hashes
+
+**Objective:** The engine should automatically extract CAS hashes from `meta` to populate `refs`, so roles don't need to manually track them.
+
+**Strategy:** After meta extraction, walk the meta object and collect any string that looks like a CAS hash (Crockford Base32, 13 chars). This is a heuristic but works because CAS hashes are distinctive.
+
+Alternative (simpler): Let each `RoleDefinition` optionally declare a `extractRefs(meta: M) => string[]` function. For planner, this returns `meta.phases.map(p => p.hash)`. For coder, `[meta.completedPhase]`.
+
+**Recommended:** The explicit `extractRefs` approach — no magic, no false positives.
+
+**Files:**
+- Modify: `packages/workflow/src/types.ts` — add optional `extractRefs` to `RoleDefinition`
+- Modify: `packages/workflow/src/create-workflow.ts` — call `extractRefs` after meta extraction, set on `RoleOutput.refs`
+- Modify: `packages/workflow-role-planner/src/planner.ts` — implement `extractRefs`
+- Modify: `packages/workflow-role-coder/src/coder.ts` — implement `extractRefs`
+
+```typescript
+// types.ts — RoleDefinition addition
+export type RoleDefinition<Meta extends Record<string, unknown>> = {
+  description: string;
+  systemPrompt: string;
+  extractPrompt: string;
+  schema: z.ZodType<Meta>;
+  extractRefs?: (meta: Meta) => string[];  // CAS hashes to track
+};
+
+// planner.ts
+extractRefs: (meta) => meta.phases.map(p => p.hash),
+
+// coder.ts
+extractRefs: (meta) => [meta.completedPhase],
+```
+
+### Task 2.3: Update fork logic to preserve refs
+
+**Objective:** When forking a thread, `refs` from historical steps must be carried over.
+
+**Files:**
+- Modify: `packages/workflow/src/fork-thread.ts`
+- Verify: `ForkHistoricalStep` / `PrefilledDiskStep` include `refs`
+
+### Task 2.4: Tests for refs tracking
+
+**Files:**
+- Add: `packages/workflow/__tests__/refs-tracking.test.ts`
+- Verify: refs appear in `.data.jsonl` output
+
+---
+
+## Phase 3: CAS Garbage Collection
+
+### Task 3.1: Implement `gc.ts` in `@uncaged/workflow`
+
+**Objective:** Mark-and-sweep GC — scan all thread `.data.jsonl` files, collect `refs`, delete orphaned CAS entries.
+
+**Files:**
+- Create: `packages/workflow/src/gc.ts`
+- Export from: `packages/workflow/src/index.ts`
+
+```typescript
+export type GcResult = {
+  scannedThreads: number;
+  activeRefs: number;
+  deletedEntries: number;
+  deletedHashes: string[];
+};
+
+export async function garbageCollectCas(storageRoot: string): Promise<GcResult> {
+  // 1. Find all .data.jsonl files under storageRoot
+  // 2. Parse each, flatMap step.refs → Set<string>
+  // 3. List all CAS entries via createCasStore(globalCasDir).list()
+  // 4. Delete entries not in active set
+  // 5. Return stats
+}
+```
+
+### Task 3.2: Add `uncaged-workflow gc` CLI command
+
+**Files:**
+- Create: `packages/cli-workflow/src/cmd-gc.ts`
+- Modify: `packages/cli-workflow/src/cli-dispatch.ts` — add `gc` subcommand
+
+### Task 3.3: Run GC on `thread rm`
+
+**Files:**
+- Modify: `packages/cli-workflow/src/cmd-thread.ts` — after deleting thread data, optionally run GC
+
+### Task 3.4: Tests for GC
+
+**Files:**
+- Create: `packages/cli-workflow/__tests__/gc-cli.test.ts`
+
+---
+
+## Phase 4: `workflowAsAgent` Factory
+
+### Task 4.1: Create `workflowAsAgent` in `@uncaged/workflow`
+
+**Objective:** Factory function that takes a workflow name, resolves to bundle, returns an `AgentFn`.
+
+**Files:**
+- Create: `packages/workflow/src/workflow-as-agent.ts`
+- Export from: `packages/workflow/src/index.ts`
+
+```typescript
+import type { AgentFn } from "./types.js";
+
+export type WorkflowAsAgentOptions = {
+  storageRoot?: string;
+};
+
+export function workflowAsAgent(
+  workflowName: string,
+  options?: WorkflowAsAgentOptions,
+): AgentFn {
+  return async (ctx) => {
+    const storageRoot = options?.storageRoot ?? getDefaultWorkflowStorageRoot();
+
+    // 1. Read registry → resolve name to bundle hash + path
+    const registry = await readWorkflowRegistry(storageRoot);
+    const entry = getRegisteredWorkflow(registry, workflowName);
+    if (entry === null) {
+      return `ERROR: workflow "${workflowName}" not found in registry`;
+    }
+
+    // 2. Load bundle
+    const bundlePath = join(storageRoot, "bundles", `${entry.hash}.esm.js`);
+    const bundleExports = await extractBundleExports(bundlePath);
+
+    // 3. Create child thread input from ctx.start.content (parent prompt)
+    const input: ThreadInput = {
+      prompt: ctx.start.content,
+      steps: [],
+    };
+
+    // 4. Generate child threadId
+    const childThreadId = generateUlid();
+
+    // 5. Execute — collect all yields, return final content
+    const io: ExecuteThreadIo = { ... };
+    const result = await executeThread(bundleExports.run, workflowName, input, ...);
+
+    // 6. Return summary as agent content
+    return result.summary;
+  };
+}
+```
+
+### Task 4.2: System-level depth limit
+
+**Objective:** Prevent infinite recursion. Track depth via thread metadata, enforce a global max (default 3, configurable in `workflow.yaml`).
+
+**Files:**
+- Modify: `packages/workflow/src/types.ts` — add `depth` to `WorkflowFnOptions`
+- Modify: `packages/workflow/src/workflow-as-agent.ts` — increment depth, check limit
+- Modify: registry or config types for `maxDepth` setting
+
+### Task 4.3: Tests for workflowAsAgent
+
+**Files:**
+- Create: `packages/workflow/__tests__/workflow-as-agent.test.ts`
+- Test: name resolution, depth limit, child thread execution
+
+### Task 4.4: Integration test — nested workflow
+
+**Objective:** Create a minimal test workflow that calls another workflow via `workflowAsAgent`.
+
+**Files:**
+- Create: `packages/workflow/__tests__/workflow-as-agent-integration.test.ts`
+
+---
+
+## Execution Order
+
+```
+Phase 1 (Global CAS) → Phase 2 (refs) → Phase 3 (GC) → Phase 4 (workflowAsAgent)
+```
+
+Each phase is independently mergeable. Phase 3 depends on Phase 2 (needs refs to know what's alive). Phase 4 depends on Phase 1 (global CAS for cross-thread sharing).
+
+## Breaking Changes
+
+- CAS storage location moves from `<thread>.cas/` to `~/.uncaged/workflow/cas/`
+- `RoleOutput` gains required `refs: string[]` field
+- Existing threads with thread-local CAS will lose access to old CAS data (acceptable — those are short-lived workflow artifacts)
+- `createThreadCas` renamed to `createCasStore` (alias kept temporarily)

packages/cli-workflow/__tests__/commands.test.ts

@@ -3,8 +3,9 @@ import { mkdir, mkdtemp, readFile, rm, unlink, writeFile } from "node:fs/promise
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 
-import { getRegisteredWorkflow, readWorkflowRegistry } from "@uncaged/workflow";
+import { getGlobalCasDir, getRegisteredWorkflow, readWorkflowRegistry } from "@uncaged/workflow";
 import { cmdAdd } from "../src/cmd-add.js";
+import { cmdCasGet, cmdCasList, cmdCasPut, cmdCasRm } from "../src/cmd-cas.js";
 import { cmdHistory } from "../src/cmd-history.js";
 import { cmdList, formatListLines } from "../src/cmd-list.js";
 import { cmdRemove } from "../src/cmd-remove.js";
@@ -371,6 +372,37 @@ export const run = async function* (input) {
     expect(bad.ok).toBe(false);
   });
 
+  test("cas put/get/list/rm use global cas dir (thread id not required for storage)", async () => {
+    const put = await cmdCasPut(storageRoot, "nonexistent-thread-id", "phase doc");
+    expect(put.ok).toBe(true);
+    if (!put.ok) {
+      return;
+    }
+    const hash = put.value;
+    const blobPath = join(getGlobalCasDir(storageRoot), `${hash}.txt`);
+    expect(await readFile(blobPath, "utf8")).toBe("phase doc");
+
+    const got = await cmdCasGet(storageRoot, "other-thread", hash);
+    expect(got.ok).toBe(true);
+    if (!got.ok) {
+      return;
+    }
+    expect(got.value).toBe("phase doc");
+
+    const listed = await cmdCasList(storageRoot, "another-thread");
+    expect(listed.ok).toBe(true);
+    if (!listed.ok) {
+      return;
+    }
+    expect(listed.value).toContain(hash);
+
+    const removed = await cmdCasRm(storageRoot, "rm-thread", hash);
+    expect(removed.ok).toBe(true);
+
+    const missing = await cmdCasGet(storageRoot, "after-rm", hash);
+    expect(missing.ok).toBe(false);
+  });
+
   test("rollback rejects missing bundle file for target hash", async () => {
     const bundleDir = join(storageRoot, "src");
     await mkdir(bundleDir, { recursive: true });

packages/cli-workflow/__tests__/thread-cli.test.ts

@@ -4,7 +4,9 @@ import { mkdir, mkdtemp, readFile, rm, writeFile } from "node:fs/promises";
 import { tmpdir } from "node:os";
 import { dirname, join } from "node:path";
 import { fileURLToPath } from "node:url";
+import { getGlobalCasDir } from "@uncaged/workflow";
 import { cmdAdd } from "../src/cmd-add.js";
+import { cmdCasPut } from "../src/cmd-cas.js";
 import { cmdKill } from "../src/cmd-kill.js";
 import { cmdPause } from "../src/cmd-pause.js";
 import { cmdPs } from "../src/cmd-ps.js";
@@ -12,7 +14,7 @@ import { cmdResume } from "../src/cmd-resume.js";
 import { cmdRun } from "../src/cmd-run.js";
 import { cmdThreadRemove, cmdThreadShow } from "../src/cmd-thread.js";
 import { cmdThreads } from "../src/cmd-threads.js";
-import { pathExists } from "../src/fs-utils.js";
+import { pathExists, readTextFileIfExists } from "../src/fs-utils.js";
 import { addCliArgs } from "./bundle-fixture.js";
 
 const threadFixtureDescriptor = `export const descriptor = {
@@ -175,6 +177,55 @@ describe("cli thread commands", () => {
     expect(await pathExists(dataPath)).toBe(false);
   });
 
+  test("thread rm does not delete global cas blobs for that thread id", async () => {
+    const bundleDir = join(storageRoot, "src");
+    await mkdir(bundleDir, { recursive: true });
+    const bundlePath = join(bundleDir, "demo.esm.js");
+    await writeFile(bundlePath, fastBundleSource, "utf8");
+
+    const added = await cmdAdd(storageRoot, addCliArgs("solve-issue", bundlePath));
+    expect(added.ok).toBe(true);
+    if (!added.ok) {
+      return;
+    }
+
+    const ran = await cmdRun(storageRoot, "solve-issue", "hello", 5);
+    expect(ran.ok).toBe(true);
+    if (!ran.ok) {
+      return;
+    }
+
+    const threadId = ran.value.threadId;
+
+    let threads = await cmdThreads(storageRoot, []);
+    for (
+      let attempt = 0;
+      attempt < 50 && threads.ok && !threads.value.some((l) => l.includes(threadId));
+      attempt++
+    ) {
+      await new Promise((r) => setTimeout(r, 20));
+      threads = await cmdThreads(storageRoot, []);
+    }
+
+    const dataPath = join(storageRoot, "logs", added.value.hash, `${threadId}.data.jsonl`);
+    const runningPath = join(dirname(dataPath), `${threadId}.running`);
+    await waitUntilRunningFileAbsent(runningPath, 120);
+
+    const put = await cmdCasPut(storageRoot, threadId, "keep-after-thread-rm");
+    expect(put.ok).toBe(true);
+    if (!put.ok) {
+      return;
+    }
+    const hash = put.value;
+    const casBlob = join(getGlobalCasDir(storageRoot), `${hash}.txt`);
+
+    const removed = await cmdThreadRemove(storageRoot, threadId);
+    expect(removed.ok).toBe(true);
+
+    const stillThere = await readTextFileIfExists(casBlob);
+    expect(stillThere).toBe("keep-after-thread-rm");
+  });
+
   test("cli entrypoint dispatches threads / ps (spawn)", () => {
     const env = { ...process.env, UNCAGED_WORKFLOW_STORAGE_ROOT: storageRoot };
     const threads = spawnSync(process.execPath, [cliEntryPath, "threads"], {

packages/cli-workflow/src/cmd-cas.ts

@@ -1,23 +1,11 @@
-import { dirname, join } from "node:path";
-
-import { createThreadCas, err, ok, type Result } from "@uncaged/workflow";
-
-import { resolveThreadDataPath } from "./thread-scan.js";
-
-function resolveCasDir(threadDataPath: string, threadId: string): string {
-  return join(dirname(threadDataPath), `${threadId}.cas`);
-}
+import { createCasStore, err, getGlobalCasDir, ok, type Result } from "@uncaged/workflow";
 
 export async function cmdCasGet(
   storageRoot: string,
-  threadId: string,
+  _threadId: string,
   hash: string,
 ): Promise<Result<string, string>> {
-  const dataPath = await resolveThreadDataPath(storageRoot, threadId);
-  if (dataPath === null) {
-    return err(`thread not found: ${threadId}`);
-  }
-  const cas = createThreadCas(resolveCasDir(dataPath, threadId));
+  const cas = createCasStore(getGlobalCasDir(storageRoot));
   const content = await cas.get(hash);
   if (content === null) {
     return err(`cas entry not found: ${hash}`);
@@ -27,41 +15,29 @@ export async function cmdCasGet(
 
 export async function cmdCasPut(
   storageRoot: string,
-  threadId: string,
+  _threadId: string,
   content: string,
 ): Promise<Result<string, string>> {
-  const dataPath = await resolveThreadDataPath(storageRoot, threadId);
-  if (dataPath === null) {
-    return err(`thread not found: ${threadId}`);
-  }
-  const cas = createThreadCas(resolveCasDir(dataPath, threadId));
+  const cas = createCasStore(getGlobalCasDir(storageRoot));
   const hash = await cas.put(content);
   return ok(hash);
 }
 
 export async function cmdCasList(
   storageRoot: string,
-  threadId: string,
+  _threadId: string,
 ): Promise<Result<string[], string>> {
-  const dataPath = await resolveThreadDataPath(storageRoot, threadId);
-  if (dataPath === null) {
-    return err(`thread not found: ${threadId}`);
-  }
-  const cas = createThreadCas(resolveCasDir(dataPath, threadId));
+  const cas = createCasStore(getGlobalCasDir(storageRoot));
   const hashes = await cas.list();
   return ok(hashes);
 }
 
 export async function cmdCasRm(
   storageRoot: string,
-  threadId: string,
+  _threadId: string,
   hash: string,
 ): Promise<Result<void, string>> {
-  const dataPath = await resolveThreadDataPath(storageRoot, threadId);
-  if (dataPath === null) {
-    return err(`thread not found: ${threadId}`);
-  }
-  const cas = createThreadCas(resolveCasDir(dataPath, threadId));
+  const cas = createCasStore(getGlobalCasDir(storageRoot));
   await cas.delete(hash);
   return ok(undefined);
 }

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

@@ -1,4 +1,4 @@
-import { rm, unlink } from "node:fs/promises";
+import { unlink } from "node:fs/promises";
 import { dirname, join } from "node:path";
 
 import { err, ok, type Result } from "@uncaged/workflow";
@@ -33,12 +33,10 @@ export async function cmdThreadRemove(
   const dir = dirname(dataPath);
   const infoPath = join(dir, `${threadId}.info.jsonl`);
   const runningPath = join(dir, `${threadId}.running`);
-  const casPath = join(dir, `${threadId}.cas`);
 
   await unlink(dataPath);
   await unlink(infoPath).catch(() => {});
   await unlink(runningPath).catch(() => {});
-  await rm(casPath, { recursive: true, force: true });
 
   return ok(undefined);
 }

packages/workflow-role-coder/src/coder.ts

@@ -10,9 +10,24 @@ export const coderMetaSchema = z.object({
 export type CoderMeta = z.infer<typeof coderMetaSchema>;
 
 const CODER_SYSTEM = `You are a **coder**. Read the thread for the plan and work on the NEXT incomplete phase only.
+
+## Finding the current thread ID
+
+The thread ID is a 26-character Crockford Base32 string (e.g. \`06F03H5V6JTMDST6P3TVH42RWM\`). It appears in the first message of this conversation. If you are unsure, run:
+
+  uncaged-workflow threads
+
+and use the ID of the active thread.
+
+## Reading phase details
+
 Each planner phase is identified by a content-hash and a title. To read a phase's full details (name, description, acceptance criteria), run:
 
-  uncaged-workflow cas get <thread-id> <hash>
+  uncaged-workflow cas get <THREAD_ID> <HASH>
+
+Replace \`<THREAD_ID>\` with the actual thread ID and \`<HASH>\` with the phase hash from the plan.
+
+## Completing a phase
 
 Report which phase you completed using the phase **hash** (not the title). If you legitimately finish every remaining phase in this single turn, set completedPhase to the **last** phase hash in the plan (the workflow treats that as full completion). List the files you changed and summarize what you did.`;
 

packages/workflow-role-planner/src/planner.ts

@@ -14,16 +14,34 @@ export type PlannerMeta = z.infer<typeof plannerMetaSchema>;
 
 const PLANNER_SYSTEM = `You are a **planner** for a software task. Break the work into **sequential phases** the coder will execute one at a time.
 
-For each phase, decide on a name, detailed description, and acceptance criteria. Then store the full detail text in CAS so the coder can retrieve it later:
+## Finding the current thread ID
 
-  uncaged-workflow cas put <thread-id> "# <name>\n\nDescription: <description>\n\nAcceptance: <acceptance>"
+The thread ID is a 26-character Crockford Base32 string (e.g. \`06F03H5V6JTMDST6P3TVH42RWM\`). It appears in the first message of this conversation. If you are unsure, run:
 
-The command prints a content-hash to stdout. Use that hash as the phase identifier.
+  uncaged-workflow threads
 
-Your final structured output must contain compact phases only:
+and use the ID of the active thread.
+
+## Storing phase details — MANDATORY
+
+For each phase you MUST store its full detail text in CAS using this exact CLI command:
+
+  uncaged-workflow cas put <THREAD_ID> '# <name>
+
+Description: <description>
+
+Acceptance: <acceptance>'
+
+Replace \`<THREAD_ID>\` with the actual thread ID you found above. The command prints a content-hash to stdout — use that hash as the phase identifier.
+
+**Do NOT store phase details in any other way** (no temp files, no invented paths). The CLI command is the only supported storage mechanism.
+
+## Output format
+
+After storing all phases via the CLI, output compact JSON only:
   { "phases": [{ "hash": "<hash-from-cas-put>", "title": "<one-line-summary>" }] }
 
-The current thread ID is provided in the thread context. Order phases so earlier steps unblock later ones. Cover root cause, edge cases, and verification across the phases.`;
+Order phases so earlier steps unblock later ones. Cover root cause, edge cases, and verification across the phases.`;
 
 export const plannerRole: RoleDefinition<PlannerMeta> = {
   description: "Breaks the task into sequential phases for the coder.",

packages/workflow-role-preparer/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "@uncaged/workflow-role-preparer",
+  "version": "0.1.0",
+  "type": "module",
+  "main": "src/index.ts",
+  "types": "src/index.ts",
+  "scripts": {
+    "build": "echo 'TODO'",
+    "test": "echo no tests"
+  },
+  "dependencies": {
+    "@uncaged/workflow": "workspace:*",
+    "zod": "^4.0.0"
+  }
+}

packages/workflow-role-preparer/src/index.ts

@@ -0,0 +1,5 @@
+export {
+  type PreparerMeta,
+  preparerMetaSchema,
+  preparerRole,
+} from "./preparer.js";

packages/workflow-role-preparer/src/preparer.ts

@@ -0,0 +1,50 @@
+import type { RoleDefinition } from "@uncaged/workflow";
+import * as z from "zod/v4";
+
+const toolchainSchema = z.object({
+  packageManager: z.union([z.string(), z.null()]),
+  testCommand: z.union([z.string(), z.null()]),
+  lintCommand: z.union([z.string(), z.null()]),
+  buildCommand: z.union([z.string(), z.null()]),
+});
+
+export const preparerMetaSchema = z.object({
+  repoPath: z.string(),
+  defaultBranch: z.string(),
+  conventions: z.union([z.string(), z.null()]),
+  toolchain: toolchainSchema,
+});
+
+export type PreparerMeta = z.infer<typeof preparerMetaSchema>;
+
+const PREPARER_SYSTEM = `You are a **preparer** for a software task. Your job is to locate (or clone) the target repository locally, ensure it is up to date, and gather project context before work begins.
+
+## Responsibilities
+
+1. Parse the issue/task prompt to identify the target repository (URL, org/repo, or name).
+2. Search for an existing local clone in these locations (in order):
+   - ~/Code/<repo-name>/
+   - ~/repos/<repo-name>/
+   - ~/Code/<org>/<repo-name>/
+   - ~/repos/<org>/<repo-name>/
+3. If not found locally, \`git clone\` it into ~/repos/<repo-name>/.
+4. \`git checkout main && git pull\` (or the default branch) to ensure latest.
+5. Read project conventions: \`CLAUDE.md\`, \`CONTRIBUTING.md\`, \`.cursor/rules/*.mdc\`, \`CONVENTIONS.md\`.
+6. Detect toolchain: package manager, test runner, linter, build system.
+
+## Output
+
+Report your findings as structured data:
+- **repoPath**: absolute path to the local repo
+- **defaultBranch**: the default branch name (e.g. "main")
+- **conventions**: a summary of project conventions found, or null if none
+- **toolchain**: detected commands for packageManager, testCommand, lintCommand, buildCommand (null if not detected)`;
+
+export const preparerRole: RoleDefinition<PreparerMeta> = {
+  description:
+    "Locates or clones the target repository, ensures it is up to date, and gathers project context (conventions, toolchain).",
+  systemPrompt: PREPARER_SYSTEM,
+  extractPrompt:
+    "Extract repoPath (absolute path), defaultBranch, conventions (summary string or null), and toolchain (packageManager, testCommand, lintCommand, buildCommand — each string or null).",
+  schema: preparerMetaSchema,
+};

packages/workflow-role-preparer/tsconfig.json

@@ -0,0 +1,8 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "dist"
+  },
+  "include": ["src"]
+}

packages/workflow-template-solve-issue/__tests__/solve-issue-template.test.ts

@@ -10,6 +10,7 @@ import {
 
 import type { CoderMeta } from "@uncaged/workflow-role-coder";
 import type { PlannerMeta } from "@uncaged/workflow-role-planner";
+import type { PreparerMeta } from "@uncaged/workflow-role-preparer";
 
 import { buildSolveIssueDescriptor } from "../src/descriptor.js";
 import { createSolveIssueRun, solveIssueModerator } from "../src/index.js";
@@ -108,6 +109,25 @@ function makeCtx(
   };
 }
 
+function preparerStep(): RoleStep<SolveIssueMeta> {
+  return {
+    role: "preparer",
+    content: "prepared",
+    meta: {
+      repoPath: "/home/user/repos/test",
+      defaultBranch: "main",
+      conventions: null,
+      toolchain: {
+        packageManager: "bun",
+        testCommand: "bun test",
+        lintCommand: null,
+        buildCommand: "bun run build",
+      },
+    },
+    timestamp: 0,
+  };
+}
+
 function plannerStep(phases: PlannerMeta["phases"] = DEFAULT_PHASES): RoleStep<SolveIssueMeta> {
   return {
     role: "planner",
@@ -153,16 +173,27 @@ const stubExtract = createExtract({
 });
 
 describe("solveIssueModerator", () => {
-  test("routes planner → coder → reviewer → committer → END", () => {
-    expect(solveIssueModerator(makeCtx(20, []))).toBe("planner");
-    expect(solveIssueModerator(makeCtx(20, [plannerStep()]))).toBe("coder");
-    expect(solveIssueModerator(makeCtx(20, [plannerStep(), coderStep()]))).toBe("reviewer");
-    expect(solveIssueModerator(makeCtx(20, [plannerStep(), coderStep(), reviewerStep(true)]))).toBe(
-      "committer",
+  test("routes preparer → planner → coder → reviewer → committer → END", () => {
+    expect(solveIssueModerator(makeCtx(20, []))).toBe("preparer");
+    expect(solveIssueModerator(makeCtx(20, [preparerStep()]))).toBe("planner");
+    expect(solveIssueModerator(makeCtx(20, [preparerStep(), plannerStep()]))).toBe("coder");
+    expect(solveIssueModerator(makeCtx(20, [preparerStep(), plannerStep(), coderStep()]))).toBe(
+      "reviewer",
     );
     expect(
       solveIssueModerator(
-        makeCtx(20, [plannerStep(), coderStep(), reviewerStep(true), committerStep()]),
+        makeCtx(20, [preparerStep(), plannerStep(), coderStep(), reviewerStep(true)]),
+      ),
+    ).toBe("committer");
+    expect(
+      solveIssueModerator(
+        makeCtx(20, [
+          preparerStep(),
+          plannerStep(),
+          coderStep(),
+          reviewerStep(true),
+          committerStep(),
+        ]),
       ),
     ).toBe(END);
   });
@@ -250,8 +281,19 @@ describe("createSolveIssueRun", () => {
     restoreFetch = null;
   });
 
-  test("structured extraction yields planner meta from mocked chat completions", async () => {
-    restoreFetch = installMockChatCompletions([EXPECT_PLANNER_META]);
+  test("structured extraction yields preparer then planner meta from mocked chat completions", async () => {
+    const EXPECT_PREPARER_META: PreparerMeta = {
+      repoPath: "/home/user/repos/test",
+      defaultBranch: "main",
+      conventions: null,
+      toolchain: {
+        packageManager: "bun",
+        testCommand: "bun test",
+        lintCommand: null,
+        buildCommand: "bun run build",
+      },
+    };
+    restoreFetch = installMockChatCompletions([EXPECT_PREPARER_META, EXPECT_PLANNER_META]);
 
     const run = createSolveIssueRun({ agent: async () => "" }, stubExtract);
     const gen = run(
@@ -263,12 +305,30 @@ describe("createSolveIssueRun", () => {
     if (first.done) {
       throw new Error("expected yield");
     }
-    expect(first.value.role).toBe("planner");
-    expect(first.value.meta).toEqual(EXPECT_PLANNER_META);
+    expect(first.value.role).toBe("preparer");
+    expect(first.value.meta).toEqual(EXPECT_PREPARER_META);
+
+    const second = await gen.next();
+    expect(second.done).toBe(false);
+    if (second.done) {
+      throw new Error("expected yield");
+    }
+    expect(second.value.role).toBe("planner");
+    expect(second.value.meta).toEqual(EXPECT_PLANNER_META);
   });
 
   test("per-role agent overrides default", async () => {
-    restoreFetch = installMockChatCompletions([EXPECT_PLANNER_META, EXPECT_CODER_META]);
+    const PREPARER_META: PreparerMeta = {
+      repoPath: "/tmp/r",
+      defaultBranch: "main",
+      conventions: null,
+      toolchain: { packageManager: null, testCommand: null, lintCommand: null, buildCommand: null },
+    };
+    restoreFetch = installMockChatCompletions([
+      PREPARER_META,
+      EXPECT_PLANNER_META,
+      EXPECT_CODER_META,
+    ]);
 
     const calls: string[] = [];
     const run = createSolveIssueRun(
@@ -278,6 +338,10 @@ describe("createSolveIssueRun", () => {
           return "";
         },
         overrides: {
+          preparer: async () => {
+            calls.push("preparer");
+            return "";
+          },
           planner: async () => {
             calls.push("planner");
             return "";
@@ -295,6 +359,10 @@ describe("createSolveIssueRun", () => {
       { threadId: "01TEST000000000000000000TR", maxRounds: 20 },
     );
     await gen.next();
+    expect(calls).toEqual(["preparer"]);
+
+    calls.length = 0;
+    await gen.next();
     expect(calls).toEqual(["planner"]);
 
     calls.length = 0;
@@ -315,9 +383,10 @@ describe("buildSolveIssueDescriptor", () => {
       "coder",
       "committer",
       "planner",
+      "preparer",
       "reviewer",
     ]);
-    for (const key of ["planner", "coder", "reviewer", "committer"] as const) {
+    for (const key of ["preparer", "planner", "coder", "reviewer", "committer"] as const) {
       const role = validated.value.roles[key];
       expect(role).toBeDefined();
       expect(typeof role.schema).toBe("object");

packages/workflow-template-solve-issue/package.json

@@ -13,6 +13,7 @@
     "@uncaged/workflow-role-committer": "workspace:*",
     "@uncaged/workflow-role-coder": "workspace:*",
     "@uncaged/workflow-role-planner": "workspace:*",
+    "@uncaged/workflow-role-preparer": "workspace:*",
     "@uncaged/workflow-role-reviewer": "workspace:*"
   }
 }

packages/workflow-template-solve-issue/src/index.ts

@@ -25,6 +25,11 @@ export {
   plannerMetaSchema,
   plannerRole,
 } from "@uncaged/workflow-role-planner";
+export {
+  type PreparerMeta,
+  preparerMetaSchema,
+  preparerRole,
+} from "@uncaged/workflow-role-preparer";
 export {
   type ReviewerMeta,
   reviewerMetaSchema,

packages/workflow-template-solve-issue/src/moderator.ts

@@ -48,11 +48,15 @@ export const solveIssueModerator: Moderator<SolveIssueMeta> = (ctx) => {
   const maxRounds = ctx.start.meta.maxRounds;
 
   if (ctx.steps.length === 0) {
-    return "planner";
+    return "preparer";
   }
 
   const last = ctx.steps[ctx.steps.length - 1];
 
+  if (last.role === "preparer") {
+    return "planner";
+  }
+
   if (last.role === "planner") {
     return "coder";
   }

packages/workflow-template-solve-issue/src/roles.ts

@@ -2,12 +2,14 @@ import type { RoleDefinition } from "@uncaged/workflow";
 import { type CoderMeta, coderRole } from "@uncaged/workflow-role-coder";
 import { type CommitterMeta, committerRole } from "@uncaged/workflow-role-committer";
 import { type PlannerMeta, plannerRole } from "@uncaged/workflow-role-planner";
+import { type PreparerMeta, preparerRole } from "@uncaged/workflow-role-preparer";
 import { type ReviewerMeta, reviewerRole } from "@uncaged/workflow-role-reviewer";
 
 export const SOLVE_ISSUE_WORKFLOW_DESCRIPTION =
-  "Phased plan, incremental implementation per phase, review, and commit to resolve an issue end-to-end (planner → coder [repeat per phase] → reviewer → committer).";
+  "Prepare repo context, plan phases, implement incrementally, review, and commit to resolve an issue end-to-end (preparer → planner → coder [repeat per phase] → reviewer → committer).";
 
 export type SolveIssueMeta = {
+  preparer: PreparerMeta;
   planner: PlannerMeta;
   coder: CoderMeta;
   reviewer: ReviewerMeta;
@@ -19,6 +21,7 @@ export type SolveIssueRoles = {
 };
 
 export const solveIssueRoles: SolveIssueRoles = {
+  preparer: preparerRole,
   planner: plannerRole,
   coder: coderRole,
   reviewer: reviewerRole,

packages/workflow/__tests__/cas.test.ts

@@ -3,10 +3,16 @@ import { mkdtemp, rm } from "node:fs/promises";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 
-import { createThreadCas } from "../src/cas.js";
+import { createCasStore, createThreadCas } from "../src/cas.js";
 import { hashString } from "../src/hash.js";
 
-describe("createThreadCas", () => {
+describe("cas module exports", () => {
+  test("createThreadCas is a deprecated alias of createCasStore", () => {
+    expect(createThreadCas).toBe(createCasStore);
+  });
+});
+
+describe("createCasStore", () => {
   let casDir: string;
 
   beforeEach(async () => {
@@ -18,7 +24,7 @@ describe("createThreadCas", () => {
   });
 
   test("put returns consistent hash for same content", async () => {
-    const cas = createThreadCas(casDir);
+    const cas = createCasStore(casDir);
     const h1 = await cas.put("hello world");
     const h2 = await cas.put("hello world");
     expect(h1).toBe(h2);
@@ -26,14 +32,14 @@ describe("createThreadCas", () => {
   });
 
   test("put returns hash matching hashString", async () => {
-    const cas = createThreadCas(casDir);
+    const cas = createCasStore(casDir);
     const content = "some content to store";
     const h = await cas.put(content);
     expect(h).toBe(hashString(content));
   });
 
   test("get returns stored content", async () => {
-    const cas = createThreadCas(casDir);
+    const cas = createCasStore(casDir);
     const content = "line1\nline2\nline3";
     const h = await cas.put(content);
     const retrieved = await cas.get(h);
@@ -41,13 +47,13 @@ describe("createThreadCas", () => {
   });
 
   test("get returns null for missing hash", async () => {
-    const cas = createThreadCas(casDir);
+    const cas = createCasStore(casDir);
     const result = await cas.get("0000000000000");
     expect(result).toBeNull();
   });
 
   test("delete removes entry", async () => {
-    const cas = createThreadCas(casDir);
+    const cas = createCasStore(casDir);
     const h = await cas.put("to be deleted");
     await cas.delete(h);
     const result = await cas.get(h);
@@ -55,12 +61,12 @@ describe("createThreadCas", () => {
   });
 
   test("delete on missing hash does not throw", async () => {
-    const cas = createThreadCas(casDir);
+    const cas = createCasStore(casDir);
     await cas.delete("0000000000000");
   });
 
   test("list returns all stored hashes", async () => {
-    const cas = createThreadCas(casDir);
+    const cas = createCasStore(casDir);
     const h1 = await cas.put("aaa");
     const h2 = await cas.put("bbb");
     const h3 = await cas.put("ccc");
@@ -69,13 +75,13 @@ describe("createThreadCas", () => {
   });
 
   test("list returns empty array when cas dir does not exist", async () => {
-    const cas = createThreadCas(join(casDir, "nonexistent"));
+    const cas = createCasStore(join(casDir, "nonexistent"));
     const hashes = await cas.list();
     expect(hashes).toEqual([]);
   });
 
   test("put is idempotent — same content written twice causes no error", async () => {
-    const cas = createThreadCas(casDir);
+    const cas = createCasStore(casDir);
     const h1 = await cas.put("idempotent");
     const h2 = await cas.put("idempotent");
     expect(h1).toBe(h2);
@@ -84,7 +90,7 @@ describe("createThreadCas", () => {
   });
 
   test("different content produces different hashes", async () => {
-    const cas = createThreadCas(casDir);
+    const cas = createCasStore(casDir);
     const h1 = await cas.put("alpha");
     const h2 = await cas.put("beta");
     expect(h1).not.toBe(h2);

packages/workflow/__tests__/storage-root.test.ts

@@ -0,0 +1,14 @@
+import { describe, expect, test } from "bun:test";
+import { join } from "node:path";
+
+import { getDefaultWorkflowStorageRoot, getGlobalCasDir } from "../src/storage-root.js";
+
+describe("getGlobalCasDir", () => {
+  test("joins cas segment under explicit storage root", () => {
+    expect(getGlobalCasDir("/tmp/wf-root")).toBe(join("/tmp/wf-root", "cas"));
+  });
+
+  test("defaults to default workflow root when storage root is undefined", () => {
+    expect(getGlobalCasDir(undefined)).toBe(join(getDefaultWorkflowStorageRoot(), "cas"));
+  });
+});

packages/workflow/src/cas.ts

@@ -10,7 +10,7 @@ export type CasStore = {
   list(): Promise<string[]>;
 };
 
-export function createThreadCas(casDir: string): CasStore {
+export function createCasStore(casDir: string): CasStore {
   async function ensureDir(): Promise<void> {
     await mkdir(casDir, { recursive: true });
   }
@@ -68,3 +68,6 @@ export function createThreadCas(casDir: string): CasStore {
     },
   };
 }
+
+/** @deprecated Use {@link createCasStore} — CAS is global, not per-thread. */
+export const createThreadCas = createCasStore;

packages/workflow/src/index.ts

@@ -7,7 +7,7 @@ export {
 } from "./base32.js";
 export { buildDescriptor } from "./build-descriptor.js";
 export { validateWorkflowBundle, type WorkflowBundleValidationInput } from "./bundle-validator.js";
-export { type CasStore, createThreadCas } from "./cas.js";
+export { type CasStore, createCasStore, createThreadCas } from "./cas.js";
 export { createWorkflow } from "./create-workflow.js";
 export {
   type ExecuteThreadIo,
@@ -55,7 +55,7 @@ export {
   writeWorkflowRegistry,
 } from "./registry.js";
 export { err, ok, type Result } from "./result.js";
-export { getDefaultWorkflowStorageRoot } from "./storage-root.js";
+export { getDefaultWorkflowStorageRoot, getGlobalCasDir } from "./storage-root.js";
 export { createThreadPauseGate, type ThreadPauseGate } from "./thread-pause-gate.js";
 export {
   type AgentBinding,

packages/workflow/src/storage-root.ts

@@ -5,3 +5,9 @@ import { join } from "node:path";
 export function getDefaultWorkflowStorageRoot(): string {
   return join(homedir(), ".uncaged", "workflow");
 }
+
+/** Global content-addressed store directory under the workflow storage root (`<root>/cas`). */
+export function getGlobalCasDir(storageRoot: string | undefined): string {
+  const root = storageRoot ?? getDefaultWorkflowStorageRoot();
+  return join(root, "cas");
+}