feat: add thread start/show/list/kill commands

- thread start: ULID generation, StartNode to CAS, threads.yaml
- thread show: active (done:false) or archived (done:true)
- thread list: active threads, --all includes history
- thread kill: archive to history.jsonl

Refs #309, #313

packages/cli-uwf/package.json

@@ -14,6 +14,7 @@
     "@uncaged/json-cas": "workspace:^",
     "@uncaged/json-cas-fs": "workspace:^",
     "@uncaged/uwf-protocol": "workspace:^",
+    "@uncaged/workflow-util": "workspace:^",
     "commander": "^14.0.3",
     "yaml": "^2.8.4"
   },

packages/cli-uwf/src/cli.ts

@@ -2,7 +2,7 @@
 
 import { Command } from "commander";
 
-import { cmdThreadPlaceholder } from "./commands/thread.js";
+import { cmdThreadKill, cmdThreadList, cmdThreadShow, cmdThreadStart } from "./commands/thread.js";
 import { cmdWorkflowList, cmdWorkflowPut, cmdWorkflowShow } from "./commands/workflow.js";
 import { resolveStorageRoot } from "./store.js";
 
@@ -59,15 +59,19 @@ workflow
     });
   });
 
-const thread = program.command("thread").description("Thread execution (Phase 4)");
+const thread = program.command("thread").description("Thread lifecycle and execution");
 
 thread
   .command("start")
   .description("Create a thread without executing")
   .argument("<workflow>", "Workflow name or hash")
   .requiredOption("-p, --prompt <text>", "User prompt")
-  .action(() => {
-    cmdThreadPlaceholder("start");
+  .action((workflow: string, opts: { prompt: string }) => {
+    const storageRoot = resolveStorageRoot();
+    runAction(async () => {
+      const result = await cmdThreadStart(storageRoot, workflow, opts.prompt);
+      writeJson(result);
+    });
   });
 
 thread
@@ -76,31 +80,44 @@ thread
   .argument("<thread-id>", "Thread ULID")
   .option("--agent <cmd>", "Override agent command")
   .action(() => {
-    cmdThreadPlaceholder("step");
+    process.stderr.write("uwf thread step: not implemented\n");
+    process.exit(1);
   });
 
 thread
   .command("show")
   .description("Show thread head pointer")
   .argument("<thread-id>", "Thread ULID")
-  .action(() => {
-    cmdThreadPlaceholder("show");
+  .action((threadId: string) => {
+    const storageRoot = resolveStorageRoot();
+    runAction(async () => {
+      const result = await cmdThreadShow(storageRoot, threadId);
+      writeJson(result);
+    });
   });
 
 thread
   .command("list")
   .description("List active threads")
   .option("--all", "Include archived threads")
-  .action(() => {
-    cmdThreadPlaceholder("list");
+  .action((opts: { all: boolean }) => {
+    const storageRoot = resolveStorageRoot();
+    runAction(async () => {
+      const result = await cmdThreadList(storageRoot, opts.all);
+      writeJson(result);
+    });
   });
 
 thread
   .command("kill")
   .description("Terminate and archive a thread")
   .argument("<thread-id>", "Thread ULID")
-  .action(() => {
-    cmdThreadPlaceholder("kill");
+  .action((threadId: string) => {
+    const storageRoot = resolveStorageRoot();
+    runAction(async () => {
+      const result = await cmdThreadKill(storageRoot, threadId);
+      writeJson(result);
+    });
   });
 
 program.parseAsync(process.argv).catch((e: unknown) => {

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

@@ -1,9 +1,212 @@
+import { validate } from "@uncaged/json-cas";
+import type {
+  CasRef,
+  StartNodePayload,
+  StartOutput,
+  StepNodePayload,
+  StepOutput,
+  ThreadId,
+  ThreadListItem,
+} from "@uncaged/uwf-protocol";
+import { generateUlid } from "@uncaged/workflow-util";
+
+import {
+  appendThreadHistory,
+  createUwfStore,
+  findThreadInHistory,
+  loadThreadHistory,
+  loadThreadsIndex,
+  loadWorkflowRegistry,
+  resolveWorkflowHash,
+  saveThreadsIndex,
+  type ThreadHistoryLine,
+  type UwfStore,
+} from "../store.js";
+import { isCasRef } from "../validate.js";
+
+export type KillOutput = {
+  thread: ThreadId;
+  archived: boolean;
+};
+
 function fail(message: string): never {
   process.stderr.write(`${message}\n`);
   process.exit(1);
 }
 
-/** Phase 4 placeholder — thread commands are not implemented yet. */
-export function cmdThreadPlaceholder(command: string): never {
-  fail(`uwf thread ${command}: not implemented (Phase 4)`);
+async function resolveWorkflowCasRef(
+  uwf: UwfStore,
+  storageRoot: string,
+  workflowId: string,
+): Promise<CasRef> {
+  const registry = await loadWorkflowRegistry(storageRoot);
+  const hash = resolveWorkflowHash(registry, workflowId);
+  if (hash === null) {
+    fail(`workflow not found: ${workflowId}`);
+  }
+  if (!isCasRef(hash)) {
+    fail(`workflow not found: ${workflowId}`);
+  }
+  const node = uwf.store.get(hash);
+  if (node === null) {
+    fail(`CAS node not found: ${hash}`);
+  }
+  if (node.type !== uwf.schemas.workflow) {
+    fail(`node ${hash} is not a Workflow (type ${node.type})`);
+  }
+  return hash;
+}
+
+function resolveWorkflowFromHead(uwf: UwfStore, head: CasRef): CasRef | null {
+  const node = uwf.store.get(head);
+  if (node === null) {
+    return null;
+  }
+
+  if (node.type === uwf.schemas.startNode) {
+    const payload = node.payload as StartNodePayload;
+    return payload.workflow;
+  }
+
+  const payload = node.payload as StepNodePayload;
+  if (typeof payload.start !== "string") {
+    return null;
+  }
+
+  const startNode = uwf.store.get(payload.start);
+  if (startNode === null || startNode.type !== uwf.schemas.startNode) {
+    return null;
+  }
+
+  return (startNode.payload as StartNodePayload).workflow;
+}
+
+export async function cmdThreadStart(
+  storageRoot: string,
+  workflowId: string,
+  prompt: string,
+): Promise<StartOutput> {
+  const uwf = await createUwfStore(storageRoot);
+  const workflowHash = await resolveWorkflowCasRef(uwf, storageRoot, workflowId);
+
+  const threadId = generateUlid(Date.now()) as ThreadId;
+  const startPayload: StartNodePayload = {
+    workflow: workflowHash,
+    prompt,
+  };
+
+  const headHash = await uwf.store.put(uwf.schemas.startNode, startPayload);
+  const node = uwf.store.get(headHash);
+  if (node === null || !validate(uwf.store, node)) {
+    fail("stored StartNode failed schema validation");
+  }
+
+  const index = await loadThreadsIndex(storageRoot);
+  index[threadId] = headHash;
+  await saveThreadsIndex(storageRoot, index);
+
+  return { workflow: workflowHash, thread: threadId };
+}
+
+export async function cmdThreadShow(storageRoot: string, threadId: ThreadId): Promise<StepOutput> {
+  const index = await loadThreadsIndex(storageRoot);
+  const activeHead = index[threadId];
+  if (activeHead !== undefined) {
+    const uwf = await createUwfStore(storageRoot);
+    const workflow = resolveWorkflowFromHead(uwf, activeHead);
+    if (workflow === null) {
+      fail(`failed to resolve workflow from head: ${activeHead}`);
+    }
+    return {
+      workflow,
+      thread: threadId,
+      head: activeHead,
+      done: false,
+    };
+  }
+
+  const hist = await findThreadInHistory(storageRoot, threadId);
+  if (hist !== null) {
+    return {
+      workflow: hist.workflow,
+      thread: threadId,
+      head: hist.head,
+      done: true,
+    };
+  }
+
+  fail(`thread not found: ${threadId}`);
+}
+
+async function threadListItemFromActive(
+  uwf: UwfStore,
+  threadId: ThreadId,
+  head: CasRef,
+): Promise<ThreadListItem | null> {
+  const workflow = resolveWorkflowFromHead(uwf, head);
+  if (workflow === null) {
+    return null;
+  }
+  return { thread: threadId, workflow, head };
+}
+
+export async function cmdThreadList(
+  storageRoot: string,
+  includeAll: boolean,
+): Promise<ThreadListItem[]> {
+  const uwf = await createUwfStore(storageRoot);
+  const index = await loadThreadsIndex(storageRoot);
+  const items: ThreadListItem[] = [];
+
+  for (const [threadId, head] of Object.entries(index)) {
+    const item = await threadListItemFromActive(uwf, threadId as ThreadId, head);
+    if (item !== null) {
+      items.push(item);
+    }
+  }
+
+  if (!includeAll) {
+    return items;
+  }
+
+  const activeIds = new Set(items.map((i) => i.thread));
+  const history = await loadThreadHistory(storageRoot);
+  for (const entry of history) {
+    if (!activeIds.has(entry.thread)) {
+      items.push({
+        thread: entry.thread,
+        workflow: entry.workflow,
+        head: entry.head,
+      });
+    }
+  }
+
+  return items;
+}
+
+export async function cmdThreadKill(storageRoot: string, threadId: ThreadId): Promise<KillOutput> {
+  const index = await loadThreadsIndex(storageRoot);
+  const head = index[threadId];
+  if (head === undefined) {
+    fail(`thread not active: ${threadId}`);
+  }
+
+  const uwf = await createUwfStore(storageRoot);
+  const workflow = resolveWorkflowFromHead(uwf, head);
+  if (workflow === null) {
+    fail(`failed to resolve workflow from head: ${head}`);
+  }
+
+  delete index[threadId];
+  await saveThreadsIndex(storageRoot, index);
+
+  const historyEntry: ThreadHistoryLine = {
+    thread: threadId,
+    workflow,
+    head,
+    completedAt: Date.now(),
+  };
+  await appendThreadHistory(storageRoot, historyEntry);
+
+  return { thread: threadId, archived: true };
 }

packages/cli-uwf/src/store.ts

@@ -1,10 +1,10 @@
-import { mkdir, readFile, writeFile } from "node:fs/promises";
+import { appendFile, mkdir, readFile, writeFile } from "node:fs/promises";
 import { homedir } from "node:os";
 import { join } from "node:path";
 
 import type { Hash, Store } from "@uncaged/json-cas";
 import { createFsStore } from "@uncaged/json-cas-fs";
-import type { CasRef } from "@uncaged/uwf-protocol";
+import type { CasRef, ThreadId, ThreadListItem, ThreadsIndex } from "@uncaged/uwf-protocol";
 import { parse, stringify } from "yaml";
 
 import { registerUwfSchemas, type UwfSchemaHashes } from "./schemas.js";
@@ -40,6 +40,18 @@ export function getRegistryPath(storageRoot: string): string {
   return join(storageRoot, "workflows.yaml");
 }
 
+export function getThreadsPath(storageRoot: string): string {
+  return join(storageRoot, "threads.yaml");
+}
+
+export function getHistoryPath(storageRoot: string): string {
+  return join(storageRoot, "history.jsonl");
+}
+
+export type ThreadHistoryLine = ThreadListItem & {
+  completedAt: number;
+};
+
 export type UwfStore = {
   storageRoot: string;
   store: Store;
@@ -103,3 +115,101 @@ export function findRegistryName(registry: WorkflowRegistry, hash: Hash): string
   }
   return null;
 }
+
+export async function loadThreadsIndex(storageRoot: string): Promise<ThreadsIndex> {
+  const path = getThreadsPath(storageRoot);
+  try {
+    const text = await readFile(path, "utf8");
+    const raw = parse(text) as unknown;
+    if (raw === null || typeof raw !== "object" || Array.isArray(raw)) {
+      return {};
+    }
+    const index: ThreadsIndex = {};
+    for (const [threadId, head] of Object.entries(raw as Record<string, unknown>)) {
+      if (typeof head === "string") {
+        index[threadId as ThreadId] = head;
+      }
+    }
+    return index;
+  } catch (e) {
+    const err = e as NodeJS.ErrnoException;
+    if (err.code === "ENOENT") {
+      return {};
+    }
+    throw e;
+  }
+}
+
+export async function saveThreadsIndex(storageRoot: string, index: ThreadsIndex): Promise<void> {
+  const path = getThreadsPath(storageRoot);
+  await mkdir(storageRoot, { recursive: true });
+  const text = stringify(index, { indent: 2 });
+  await writeFile(path, text, "utf8");
+}
+
+export async function loadThreadHistory(storageRoot: string): Promise<ThreadHistoryLine[]> {
+  const path = getHistoryPath(storageRoot);
+  try {
+    const text = await readFile(path, "utf8");
+    const lines: ThreadHistoryLine[] = [];
+    for (const line of text.split("\n")) {
+      const trimmed = line.trim();
+      if (trimmed === "") {
+        continue;
+      }
+      let raw: unknown;
+      try {
+        raw = JSON.parse(trimmed) as unknown;
+      } catch {
+        continue;
+      }
+      if (raw === null || typeof raw !== "object" || Array.isArray(raw)) {
+        continue;
+      }
+      const rec = raw as Record<string, unknown>;
+      const thread = rec.thread;
+      const workflow = rec.workflow;
+      const head = rec.head;
+      const completedAt = rec.completedAt;
+      if (
+        typeof thread === "string" &&
+        typeof workflow === "string" &&
+        typeof head === "string" &&
+        typeof completedAt === "number"
+      ) {
+        lines.push({ thread: thread as ThreadId, workflow, head, completedAt });
+      }
+    }
+    return lines;
+  } catch (e) {
+    const err = e as NodeJS.ErrnoException;
+    if (err.code === "ENOENT") {
+      return [];
+    }
+    throw e;
+  }
+}
+
+export async function findThreadInHistory(
+  storageRoot: string,
+  threadId: ThreadId,
+): Promise<ThreadHistoryLine | null> {
+  const history = await loadThreadHistory(storageRoot);
+  for (let i = history.length - 1; i >= 0; i--) {
+    const entry = history[i];
+    if (entry !== undefined && entry.thread === threadId) {
+      return entry;
+    }
+  }
+  return null;
+}
+
+export async function appendThreadHistory(
+  storageRoot: string,
+  entry: ThreadHistoryLine,
+): Promise<void> {
+  const path = getHistoryPath(storageRoot);
+  await mkdir(storageRoot, { recursive: true });
+  const line = `${JSON.stringify(entry)}\n`;
+  await appendFile(path, line, "utf8");
+}