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# runApp

> Main entry point that starts a LiveWire agent.

[jobcontext]: /docs/server-sdks/reference/typescript/agents/livewire/job-context

[defineagent]: #defineagent

[jobprocess]: /docs/server-sdks/reference/typescript/agents/livewire/job-context

## **runApp**

```typescript {1}
function runApp(options: any): void
```

The main entry point for a LiveWire application. It prints the ASCII banner, runs
the prewarm function (if defined), creates a `JobContext`, prints a random tip,
invokes the registered entry function, and starts the underlying SignalWire agent.

This mirrors `cli.runApp()` from `@livekit/agents-js`. It is also available as
`cli.runApp`.

### Parameters

**`options`** `any` — required

The agent definition returned by [`defineAgent()`](#defineagent), or an object
with `entry` and optional `prewarm` functions.

---

### Returns

`void` -- This function runs the agent lifecycle asynchronously.

### Lifecycle

1. Prints the LiveWire ASCII banner to stderr.
2. If the agent definition has a `prewarm` function, calls it with a fresh
   [`JobProcess`][jobprocess] instance. Logs an informational message noting that
   warm process pools are not needed on SignalWire.
3. Creates a [`JobContext`][jobcontext].
4. Prints a random "Did you know?" tip to stderr.
5. Calls the `entry` function with the `JobContext`. If the entry function is async,
   it is awaited.
6. After entry completes, starts the underlying SignalWire agent if one was bound.

### Example

```typescript {27}
import {
  Agent, AgentSession, JobContext, tool, defineAgent, runApp,
} from '@signalwire/sdk/livewire';

const getTime = tool({
  description: 'Get the current time.',
  execute: () => new Date().toISOString(),
});

const agentDef = defineAgent({
  entry: async (ctx: JobContext) => {
    await ctx.connect();
    await ctx.waitForParticipant();

    const agent = new Agent({
      instructions: 'You are a helpful assistant that can tell the time.',
      tools: { getTime },
    });

    const session = new AgentSession();
    await session.start({ agent, room: ctx.room });
    session.generateReply({ instructions: 'Greet the user.' });
  },
});

runApp(agentDef);
```

---

## **defineAgent**

```typescript {1}
function defineAgent(agent: {
  entry: (ctx: JobContext) => Promise<void>;
  prewarm?: (proc: JobProcess) => any;
}): { entry: (ctx: JobContext) => Promise<void>; prewarm?: (proc: JobProcess) => any }
```

Wraps an entry function (and optional prewarm function) into an agent definition
object that can be passed to `runApp()`. This mirrors `defineAgent()` from
`@livekit/agents-js`.

### Parameters

**`entry`** `(ctx: JobContext) => Promise<void>` — required

The main entry function for the agent. Receives a [`JobContext`][jobcontext] and
should create an `Agent`, an `AgentSession`, and call `session.start()`.

---

**`prewarm`** `(proc: JobProcess) => any` — default: undefined

Optional setup function called before the entry function. Receives a
[`JobProcess`][jobprocess] whose `userData` object can be used to share state
with the entry function.

---

### Returns

The same object, for passing to `runApp()`.

### Example

```typescript {3}
import { defineAgent, runApp, JobContext, JobProcess } from '@signalwire/sdk/livewire';

const agentDef = defineAgent({
  prewarm: (proc: JobProcess) => {
    proc.userData.greeting = 'Welcome to Acme Corp!';
  },
  entry: async (ctx: JobContext) => {
    const greeting = ctx.proc.userData.greeting ?? 'Hello!';
    // ... set up agent and session
  },
});

runApp(agentDef);
```

> Main entry point that starts a LiveWire agent.