v2.0.3: CLI client + human inbox + cost tracking + Boomerang new_task

Phase 7 of v2.0. BooCoder gains a terminal-driven UX and subagent
isolation primitive.

CLI (src/cli.ts): standalone entry point for terminal use.
- boocode run "task" [--agent x] [--model y] — create + stream output
- boocode ls [--state x] — formatted task table
- boocode attach <id> — WS stream of running task
- boocode send <id> "msg" — follow-up message to task session
Connects to BOOCODER_URL (default http://100.114.205.53:9502).

Human inbox (routes/inbox.ts): GET /api/inbox (failed/blocked tasks),
POST /api/inbox/:id/retry (reset to pending for re-dispatch).

Cost tracking: dispatcher aggregates tokens_used from all messages in
the task's session after completion, stores in tasks.cost_tokens.
GET /api/stats/costs?group_by=project|agent|day for aggregation.

Boomerang subagent isolation (3 new tools):
- new_task: creates child task with parent_task_id linkage, runs in
  fresh isolated session. Orchestrator sees only output_summary.
- list_tasks: query child tasks of current parent
- check_task_status: read task state + output_summary

The orchestrator pattern: an agent with tools: [new_task, list_tasks,
check_task_status] can ONLY dispatch — can't read files or MCP. This
is the Roo Code Boomerang Tasks capability-restriction principle.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/coder/package.json

@@ -8,6 +8,7 @@
     "dev": "tsx watch src/index.ts",
     "build": "tsc && node -e \"import('node:fs').then(fs=>fs.copyFileSync('src/schema.sql','dist/schema.sql'))\"",
     "start": "node dist/index.js",
+    "cli": "tsx src/cli.ts",
     "typecheck": "tsc --noEmit",
     "test": "vitest run"
   },
@@ -19,10 +20,12 @@
     "@modelcontextprotocol/sdk": "^1.29.0",
     "fastify": "^4.28.1",
     "postgres": "^3.4.4",
+    "ws": "^8.18.0",
     "zod": "^3.23.8"
   },
   "devDependencies": {
     "@types/node": "^20.14.10",
+    "@types/ws": "^8.5.10",
     "tsx": "^4.16.2",
     "typescript": "^5.5.0",
     "vitest": "^3.0.0"

apps/coder/src/cli.ts

@@ -0,0 +1,249 @@
+#!/usr/bin/env node
+/**
+ * BooCoder CLI client.
+ *
+ * Usage:
+ *   boocode run "task description" [--agent opencode] [--model claude-opus-4-7] [--project <id>]
+ *   boocode ls [--state pending|running|completed|failed]
+ *   boocode attach <task-id>
+ *   boocode send <task-id> "message"
+ */
+import { WebSocket } from 'ws';
+
+const BASE_URL = process.env.BOOCODER_URL ?? 'http://100.114.205.53:9502';
+
+// ─── Arg parsing ─────────────────────────────────────────────────────────────
+
+function getFlag(args: string[], name: string): string | undefined {
+  const idx = args.indexOf(name);
+  if (idx === -1 || idx + 1 >= args.length) return undefined;
+  return args[idx + 1];
+}
+
+function hasFlag(args: string[], name: string): boolean {
+  return args.includes(name);
+}
+
+// ─── HTTP helpers ────────────────────────────────────────────────────────────
+
+async function api(method: string, path: string, body?: unknown): Promise<unknown> {
+  const url = `${BASE_URL}${path}`;
+  const res = await fetch(url, {
+    method,
+    headers: body ? { 'Content-Type': 'application/json' } : undefined,
+    body: body ? JSON.stringify(body) : undefined,
+  });
+  if (!res.ok) {
+    const text = await res.text().catch(() => '');
+    throw new Error(`${method} ${path} → ${res.status}: ${text}`);
+  }
+  return res.json();
+}
+
+// ─── WS streaming ────────────────────────────────────────────────────────────
+
+function streamSession(sessionId: string): void {
+  const wsUrl = BASE_URL.replace(/^http/, 'ws') + `/api/ws/sessions/${sessionId}`;
+  const ws = new WebSocket(wsUrl);
+
+  ws.on('message', (data) => {
+    try {
+      const frame = JSON.parse(data.toString()) as { type: string; content?: string; name?: string; arguments?: string };
+      if (frame.type === 'delta' && frame.content) {
+        process.stdout.write(frame.content);
+      } else if (frame.type === 'tool_call') {
+        process.stdout.write(`\n[tool: ${frame.name ?? '?'}(${(frame.arguments ?? '').slice(0, 80)})]\n`);
+      } else if (frame.type === 'tool_result') {
+        process.stdout.write(`[tool_result]\n`);
+      } else if (frame.type === 'status' || frame.type === 'chat_status') {
+        // Silent
+      }
+    } catch {
+      // Non-JSON frame, ignore
+    }
+  });
+
+  ws.on('error', (err) => {
+    process.stderr.write(`WS error: ${err.message}\n`);
+  });
+
+  ws.on('close', () => {
+    process.stdout.write('\n');
+    process.exit(0);
+  });
+
+  process.on('SIGINT', () => {
+    ws.close();
+    process.exit(0);
+  });
+}
+
+// ─── Commands ────────────────────────────────────────────────────────────────
+
+async function cmdRun(args: string[]): Promise<void> {
+  const input = args.find((a) => !a.startsWith('--'));
+  if (!input) {
+    process.stderr.write('Usage: boocode run "task description" [--agent X] [--model X] [--project X]\n');
+    process.exit(1);
+  }
+
+  const agent = getFlag(args, '--agent');
+  const model = getFlag(args, '--model');
+  const project_id = getFlag(args, '--project');
+
+  if (!project_id) {
+    process.stderr.write('Error: --project <uuid> is required\n');
+    process.exit(1);
+  }
+
+  const result = (await api('POST', '/api/tasks', {
+    project_id,
+    input,
+    ...(agent && { agent }),
+    ...(model && { model }),
+  })) as { id: string; state: string };
+
+  process.stdout.write(`Task created: ${result.id} (state: ${result.state})\n`);
+
+  // Poll until task has session_id, then stream; or poll until terminal state
+  const POLL_MS = 2000;
+  for (;;) {
+    await sleep(POLL_MS);
+    const task = (await api('GET', `/api/tasks/${result.id}`)) as {
+      id: string; state: string; session_id?: string; output_summary?: string;
+    };
+
+    if (task.session_id) {
+      process.stdout.write(`Streaming session ${task.session_id}...\n`);
+      streamSession(task.session_id);
+      return; // streamSession handles exit
+    }
+
+    if (task.state === 'completed') {
+      process.stdout.write(`\nCompleted: ${task.output_summary ?? '(no summary)'}\n`);
+      return;
+    }
+    if (task.state === 'failed') {
+      process.stderr.write(`\nFailed: ${task.output_summary ?? '(no summary)'}\n`);
+      process.exit(1);
+    }
+    if (task.state === 'cancelled') {
+      process.stderr.write(`\nCancelled.\n`);
+      process.exit(1);
+    }
+  }
+}
+
+async function cmdLs(args: string[]): Promise<void> {
+  const state = getFlag(args, '--state');
+  const query = state ? `?state=${state}` : '';
+  const tasks = (await api('GET', `/api/tasks${query}`)) as Array<{
+    id: string; state: string; agent: string | null; input: string; created_at: string;
+  }>;
+
+  if (tasks.length === 0) {
+    process.stdout.write('No tasks.\n');
+    return;
+  }
+
+  // Table header
+  process.stdout.write(
+    pad('ID', 38) + pad('STATE', 12) + pad('AGENT', 14) + pad('INPUT', 52) + 'CREATED\n',
+  );
+  process.stdout.write('-'.repeat(120) + '\n');
+
+  for (const t of tasks) {
+    process.stdout.write(
+      pad(t.id, 38) +
+      pad(t.state, 12) +
+      pad(t.agent ?? '-', 14) +
+      pad(t.input.slice(0, 50), 52) +
+      (t.created_at?.slice(0, 19) ?? '') + '\n',
+    );
+  }
+}
+
+async function cmdAttach(args: string[]): Promise<void> {
+  const taskId = args[0];
+  if (!taskId) {
+    process.stderr.write('Usage: boocode attach <task-id>\n');
+    process.exit(1);
+  }
+
+  const task = (await api('GET', `/api/tasks/${taskId}`)) as { session_id?: string };
+  if (!task.session_id) {
+    process.stderr.write('Task has no session yet (still pending?).\n');
+    process.exit(1);
+  }
+
+  streamSession(task.session_id);
+}
+
+async function cmdSend(args: string[]): Promise<void> {
+  const taskId = args[0];
+  const message = args[1];
+  if (!taskId || !message) {
+    process.stderr.write('Usage: boocode send <task-id> "message"\n');
+    process.exit(1);
+  }
+
+  const task = (await api('GET', `/api/tasks/${taskId}`)) as { session_id?: string };
+  if (!task.session_id) {
+    process.stderr.write('Task has no session yet.\n');
+    process.exit(1);
+  }
+
+  // Find active chat
+  const sessionId = task.session_id;
+  // POST message to the session's chat (the messages route expects session_id in path)
+  await api('POST', `/api/sessions/${sessionId}/messages`, { content: message });
+
+  // Then attach to stream the response
+  streamSession(sessionId);
+}
+
+// ─── Utils ───────────────────────────────────────────────────────────────────
+
+function pad(s: string, width: number): string {
+  return s.length >= width ? s.slice(0, width) : s + ' '.repeat(width - s.length);
+}
+
+function sleep(ms: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+// ─── Main ────────────────────────────────────────────────────────────────────
+
+const [cmd, ...rest] = process.argv.slice(2);
+
+switch (cmd) {
+  case 'run':
+    cmdRun(rest).catch(fatal);
+    break;
+  case 'ls':
+    cmdLs(rest).catch(fatal);
+    break;
+  case 'attach':
+    cmdAttach(rest).catch(fatal);
+    break;
+  case 'send':
+    cmdSend(rest).catch(fatal);
+    break;
+  default:
+    process.stdout.write(
+      'BooCoder CLI\n\n' +
+      'Commands:\n' +
+      '  run "task"  [--agent X] [--model X] [--project <id>]   Create and stream a task\n' +
+      '  ls          [--state pending|running|completed|failed]   List tasks\n' +
+      '  attach      <task-id>                                    Stream a running task\n' +
+      '  send        <task-id> "message"                          Send input to a task\n' +
+      '\n' +
+      `Base URL: ${BASE_URL} (set BOOCODER_URL to override)\n`,
+    );
+    if (cmd && cmd !== '--help' && cmd !== '-h') process.exit(1);
+}
+
+function fatal(err: unknown): void {
+  process.stderr.write(`Error: ${err instanceof Error ? err.message : String(err)}\n`);
+  process.exit(1);
+}

apps/coder/src/index.ts

@@ -25,6 +25,8 @@ import { setInferenceContext, clearInferenceContext } from './services/tools/inf
 import { registerMessageRoutes } from './routes/messages.js';
 import { registerPendingRoutes } from './routes/pending.js';
 import { registerTaskRoutes } from './routes/tasks.js';
+import { registerInboxRoutes } from './routes/inbox.js';
+import { registerStatsRoutes } from './routes/stats.js';
 import { registerWebSocket } from './routes/ws.js';
 // Phase 4: dispatcher + agent probe
 import { createDispatcher } from './services/dispatcher.js';
@@ -139,6 +141,8 @@ async function main() {
   registerMessageRoutes(app, sql, broker, inferenceApi);
   registerPendingRoutes(app, sql);
   registerTaskRoutes(app, sql, inferenceApi);
+  registerInboxRoutes(app, sql);
+  registerStatsRoutes(app, sql);
   registerWebSocket(app, sql, broker);
 
   // Serve static frontend (built web app). In production, the dist/ is

apps/coder/src/routes/inbox.ts

@@ -0,0 +1,33 @@
+import type { FastifyInstance } from 'fastify';
+import type { Sql } from '../db.js';
+
+export function registerInboxRoutes(app: FastifyInstance, sql: Sql): void {
+  // GET /api/inbox — tasks needing human attention (blocked or failed)
+  app.get('/api/inbox', async () => {
+    return sql`
+      SELECT id, project_id, parent_task_id, state, input, output_summary, agent, model, session_id, started_at, ended_at, created_at
+      FROM human_inbox
+      ORDER BY created_at DESC
+      LIMIT 100
+    `;
+  });
+
+  // POST /api/inbox/:id/retry — reset a blocked/failed task to pending for re-dispatch
+  app.post<{ Params: { id: string } }>('/api/inbox/:id/retry', async (req, reply) => {
+    const taskId = req.params.id;
+
+    const result = await sql`
+      UPDATE tasks
+      SET state = 'pending', started_at = NULL, ended_at = NULL, output_summary = NULL
+      WHERE id = ${taskId} AND state IN ('blocked', 'failed')
+      RETURNING id, state
+    `;
+
+    if (result.length === 0) {
+      reply.code(404);
+      return { error: 'task not found or not in retryable state' };
+    }
+
+    return { id: result[0]!.id, state: result[0]!.state };
+  });
+}

apps/coder/src/routes/stats.ts

@@ -0,0 +1,48 @@
+import type { FastifyInstance } from 'fastify';
+import { z } from 'zod';
+import type { Sql } from '../db.js';
+
+const CostQuery = z.object({
+  group_by: z.enum(['project', 'agent', 'day']).default('project'),
+});
+
+export function registerStatsRoutes(app: FastifyInstance, sql: Sql): void {
+  // GET /api/stats/costs — aggregate cost_tokens by project, agent, or day
+  app.get('/api/stats/costs', async (req, reply) => {
+    const parsed = CostQuery.safeParse(req.query);
+    if (!parsed.success) {
+      reply.code(400);
+      return { error: 'invalid query', details: parsed.error.flatten() };
+    }
+
+    const { group_by } = parsed.data;
+
+    switch (group_by) {
+      case 'project':
+        return sql`
+          SELECT project_id, COUNT(*)::int AS task_count, COALESCE(SUM(cost_tokens), 0)::int AS total_tokens
+          FROM tasks
+          WHERE cost_tokens IS NOT NULL
+          GROUP BY project_id
+          ORDER BY total_tokens DESC
+        `;
+      case 'agent':
+        return sql`
+          SELECT COALESCE(agent, 'native') AS agent, COUNT(*)::int AS task_count, COALESCE(SUM(cost_tokens), 0)::int AS total_tokens
+          FROM tasks
+          WHERE cost_tokens IS NOT NULL
+          GROUP BY agent
+          ORDER BY total_tokens DESC
+        `;
+      case 'day':
+        return sql`
+          SELECT DATE(created_at) AS day, COUNT(*)::int AS task_count, COALESCE(SUM(cost_tokens), 0)::int AS total_tokens
+          FROM tasks
+          WHERE cost_tokens IS NOT NULL
+          GROUP BY DATE(created_at)
+          ORDER BY day DESC
+          LIMIT 90
+        `;
+    }
+  });
+}

apps/coder/src/services/dispatcher.ts

@@ -134,6 +134,14 @@ export function createDispatcher(deps: Deps): { start(): void; stop(): Promise<v
         return;
       }
 
+      // Aggregate token cost for the task's session
+      const [costRow] = await sql<{ total: number | null }[]>`
+        SELECT SUM(tokens_used)::int AS total
+        FROM messages
+        WHERE session_id = ${sessionId} AND tokens_used IS NOT NULL
+      `;
+      const costTokens = costRow?.total ?? null;
+
       if (finalStatus === 'complete') {
         const [msg] = await sql<{ content: string | null }[]>`
           SELECT content FROM messages WHERE id = ${assistantId}
@@ -141,10 +149,10 @@ export function createDispatcher(deps: Deps): { start(): void; stop(): Promise<v
         const summary = (msg?.content ?? '').slice(0, 500);
         await sql`
           UPDATE tasks
-          SET state = 'completed', ended_at = clock_timestamp(), output_summary = ${summary}
+          SET state = 'completed', ended_at = clock_timestamp(), output_summary = ${summary}, cost_tokens = ${costTokens}
           WHERE id = ${taskId}
         `;
-        log.info({ taskId }, 'dispatcher: task completed (native)');
+        log.info({ taskId, costTokens }, 'dispatcher: task completed (native)');
       } else {
         const [msg] = await sql<{ content: string | null }[]>`
           SELECT content FROM messages WHERE id = ${assistantId}
@@ -152,7 +160,7 @@ export function createDispatcher(deps: Deps): { start(): void; stop(): Promise<v
         const summary = (msg?.content ?? 'Inference failed').slice(0, 500);
         await sql`
           UPDATE tasks
-          SET state = 'failed', ended_at = clock_timestamp(), output_summary = ${summary}
+          SET state = 'failed', ended_at = clock_timestamp(), output_summary = ${summary}, cost_tokens = ${costTokens}
           WHERE id = ${taskId}
         `;
         log.warn({ taskId, finalStatus }, 'dispatcher: task failed (native)');
@@ -299,13 +307,21 @@ export function createDispatcher(deps: Deps): { start(): void; stop(): Promise<v
       // Step 4: Cleanup worktree
       await cleanupWorktree(projectPath, taskId);
 
-      // Step 5: Mark task completed
+      // Step 5: Aggregate token cost
+      const [extCostRow] = await sql<{ total: number | null }[]>`
+        SELECT SUM(tokens_used)::int AS total
+        FROM messages
+        WHERE session_id = ${sessionId} AND tokens_used IS NOT NULL
+      `;
+      const extCostTokens = extCostRow?.total ?? null;
+
+      // Step 6: Mark task completed
       await sql`
         UPDATE tasks
-        SET state = 'completed', ended_at = clock_timestamp(), output_summary = ${outputSummary}
+        SET state = 'completed', ended_at = clock_timestamp(), output_summary = ${outputSummary}, cost_tokens = ${extCostTokens}
         WHERE id = ${taskId}
       `;
-      log.info({ taskId, agent }, 'dispatcher: task completed (external)');
+      log.info({ taskId, agent, costTokens: extCostTokens }, 'dispatcher: task completed (external)');
 
     } catch (err) {
       const errMsg = err instanceof Error ? err.message : String(err);

apps/coder/src/services/tools/check_task_status.ts

@@ -0,0 +1,50 @@
+import { z } from 'zod';
+import type { ToolDef, ToolContext } from './types.js';
+
+const CheckTaskStatusInput = z.object({
+  task_id: z.string().uuid().describe('ID of the task to check'),
+});
+
+type CheckTaskStatusInputT = z.infer<typeof CheckTaskStatusInput>;
+
+export const checkTaskStatusTool: ToolDef<CheckTaskStatusInputT> = {
+  name: 'check_task_status',
+  description: 'Check the status and output of a subtask by ID. Returns state, output_summary, and timing.',
+  inputSchema: CheckTaskStatusInput,
+  jsonSchema: {
+    type: 'function',
+    function: {
+      name: 'check_task_status',
+      description: 'Check the status and output of a subtask by ID.',
+      parameters: {
+        type: 'object',
+        properties: {
+          task_id: { type: 'string', description: 'ID of the task to check' },
+        },
+        required: ['task_id'],
+      },
+    },
+  },
+
+  async execute(input: CheckTaskStatusInputT, _projectRoot: string, context: ToolContext): Promise<unknown> {
+    const { sql } = context;
+
+    const [task] = await sql<{ id: string; state: string; output_summary: string | null; started_at: string | null; ended_at: string | null }[]>`
+      SELECT id, state, output_summary, started_at, ended_at
+      FROM tasks
+      WHERE id = ${input.task_id}
+    `;
+
+    if (!task) {
+      return { error: `Task ${input.task_id} not found` };
+    }
+
+    return {
+      id: task.id,
+      state: task.state,
+      output_summary: task.output_summary,
+      started_at: task.started_at,
+      ended_at: task.ended_at,
+    };
+  },
+};

apps/coder/src/services/tools/index.ts

@@ -4,6 +4,9 @@ import { createFileTool } from './create_file.js';
 import { deleteFileTool } from './delete_file.js';
 import { applyPendingTool } from './apply_pending.js';
 import { rewindTool } from './rewind.js';
+import { newTaskTool } from './new_task.js';
+import { listTasksTool } from './list_tasks.js';
+import { checkTaskStatusTool } from './check_task_status.js';
 
 export type { ToolDef, ToolContext, ToolJsonSchema } from './types.js';
 
@@ -16,6 +19,11 @@ export const WRITE_TOOLS: readonly ToolDef<any>[] = [
   deleteFileTool,
   editFileTool,
   rewindTool,
+  // Boomerang subtask tools — orchestrator agents call these to spawn/monitor child tasks.
+  // An "Orchestrator" agent profile would whitelist [new_task, list_tasks, check_task_status].
+  newTaskTool,
+  listTasksTool,
+  checkTaskStatusTool,
 ];
 
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
@@ -23,4 +31,4 @@ export const WRITE_TOOLS_BY_NAME: ReadonlyMap<string, ToolDef<any>> = new Map(
   WRITE_TOOLS.map((t) => [t.name, t]),
 );
 
-export { editFileTool, createFileTool, deleteFileTool, applyPendingTool, rewindTool };
+export { editFileTool, createFileTool, deleteFileTool, applyPendingTool, rewindTool, newTaskTool, listTasksTool, checkTaskStatusTool };

apps/coder/src/services/tools/list_tasks.ts

@@ -0,0 +1,56 @@
+import { z } from 'zod';
+import type { ToolDef, ToolContext } from './types.js';
+import { getInferenceContext } from './inference_context.js';
+
+const ListTasksInput = z.object({
+  parent_task_id: z.string().uuid().optional().describe('Filter by parent task ID. Omit to list children of current task.'),
+});
+
+type ListTasksInputT = z.infer<typeof ListTasksInput>;
+
+export const listTasksTool: ToolDef<ListTasksInputT> = {
+  name: 'list_tasks',
+  description: 'List child tasks of the current task (or a specified parent). Returns id, state, input preview, and output_summary.',
+  inputSchema: ListTasksInput,
+  jsonSchema: {
+    type: 'function',
+    function: {
+      name: 'list_tasks',
+      description: 'List child tasks of the current task (or a specified parent).',
+      parameters: {
+        type: 'object',
+        properties: {
+          parent_task_id: { type: 'string', description: 'Filter by parent task ID. Omit to list children of current task.' },
+        },
+        required: [],
+      },
+    },
+  },
+
+  async execute(input: ListTasksInputT, _projectRoot: string, context: ToolContext): Promise<unknown> {
+    const { sql } = context;
+    const ctx = getInferenceContext();
+    const parentId = input.parent_task_id ?? ctx.taskId;
+
+    if (!parentId) {
+      return { tasks: [], note: 'No parent task context — not running inside a task.' };
+    }
+
+    const rows = await sql<{ id: string; state: string; input: string; output_summary: string | null }[]>`
+      SELECT id, state, input, output_summary
+      FROM tasks
+      WHERE parent_task_id = ${parentId}
+      ORDER BY created_at DESC
+      LIMIT 50
+    `;
+
+    return {
+      tasks: rows.map((r) => ({
+        id: r.id,
+        state: r.state,
+        input_preview: r.input.slice(0, 100),
+        output_summary: r.output_summary,
+      })),
+    };
+  },
+};

apps/coder/src/services/tools/new_task.ts

@@ -0,0 +1,65 @@
+import { z } from 'zod';
+import type { ToolDef, ToolContext } from './types.js';
+import { getInferenceContext } from './inference_context.js';
+
+const NewTaskInput = z.object({
+  input: z.string().min(1).describe('Task description for the child subtask'),
+  agent: z.string().optional().describe('Optional: dispatch to a specific agent'),
+  model: z.string().optional().describe('Optional: model override for the subtask'),
+});
+
+type NewTaskInputT = z.infer<typeof NewTaskInput>;
+
+export const newTaskTool: ToolDef<NewTaskInputT> = {
+  name: 'new_task',
+  description:
+    'Spawn a subtask that runs in isolation. The subtask gets its own session and ' +
+    'worktree. Use check_task_status to monitor progress. Only the output_summary is ' +
+    'accessible to the parent — full isolation (Boomerang pattern).',
+  inputSchema: NewTaskInput,
+  jsonSchema: {
+    type: 'function',
+    function: {
+      name: 'new_task',
+      description:
+        'Spawn a subtask that runs in isolation. The subtask gets its own session and ' +
+        'worktree. Use check_task_status to monitor progress.',
+      parameters: {
+        type: 'object',
+        properties: {
+          input: { type: 'string', description: 'Task description for the child subtask' },
+          agent: { type: 'string', description: 'Optional: dispatch to a specific agent' },
+          model: { type: 'string', description: 'Optional: model override for the subtask' },
+        },
+        required: ['input'],
+      },
+    },
+  },
+
+  async execute(input: NewTaskInputT, _projectRoot: string, context: ToolContext): Promise<unknown> {
+    const { sql } = context;
+    // Get the current task's project_id from the inference context
+    const ctx = getInferenceContext();
+    const currentTaskId = ctx.taskId;
+
+    // Look up the project_id from the current session
+    const [session] = await sql<{ project_id: string }[]>`
+      SELECT project_id FROM sessions WHERE id = ${ctx.sessionId}
+    `;
+    if (!session) {
+      return { error: 'Cannot determine project_id from current session' };
+    }
+
+    const [task] = await sql<{ id: string; state: string }[]>`
+      INSERT INTO tasks (project_id, parent_task_id, input, agent, model)
+      VALUES (${session.project_id}, ${currentTaskId}, ${input.input}, ${input.agent ?? null}, ${input.model ?? null})
+      RETURNING id, state
+    `;
+
+    return {
+      message: `Subtask created (id: ${task!.id}). It will run in isolation. Use check_task_status to monitor.`,
+      task_id: task!.id,
+      state: task!.state,
+    };
+  },
+};