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# TypeScript Agent Lifecycle

## TypeScript Lifecycle

`@band-ai/sdk` 1.0.0 starts and stops in this order:

```text
Agent.create() → start()
                   ├── getAgentMe()                 name, description, feature flags; skipped when identity is set and tasks is off
                   ├── onStarted(name, description) before the WebSocket opens
                   ├── connect, subscribe agent_rooms and enabled agent_contacts
                   └── subscribe existing rooms     each room then catches up on /messages/next
                 running
                 stop(timeoutMs) → stop each room, onCleanup(roomId), disconnect, onRuntimeStop()
```

| Method or hook                              | Behavior                                                                                                                                                                                                             |
| :------------------------------------------ | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `agent.run({ shutdownTimeoutMs, signals })` | Starts, waits, and stops on SIGINT, SIGTERM, or SIGHUP. A second signal during shutdown, or a `stop()` that rejects, exits with code 1. `signals: false` registers no handlers.                                      |
| `agent.withLifecycle(handler)`              | Starts, awaits `handler(agent)`, and stops in a `finally`. Registers no signal handlers.                                                                                                                             |
| `agent.stop(timeoutMs)`                     | Resolves `true` when every room finished its turn in time, `false` when the timeout cut one off. With no argument it waits without a limit. `run()` and `withLifecycle()` pass `shutdownTimeoutMs`, default `30000`. |
| `agent.state.status`                        | `"not_started"`, `"starting"`, `"running"`, `"stopping"`, `"stopped"`, or `"failed"`, with `error` on `"failed"`. A stopped or failed agent can be started again.                                                    |
| `onRuntimeStop()`                           | Optional adapter hook, called once per stop after every room has stopped. Release resources shared across rooms here.                                                                                                |

If a startup step fails, `start()` tears down what it built and rejects. A `stop()` during `start()` supersedes the start, which rejects with `RuntimeStateError`, and a `start()` during `stop()` rejects with `RuntimeStateError`. The TypeScript SDK takes no single-instance lock. To have Band refuse a second connection instead of replacing the first, pass `linkOptions: { conflictPolicy: "reject" }` to `Agent.create()`.

[TypeScript reference](/reference/sdk/typescript).