> Fetch clean Markdown by appending `.md` to any page URL under https://signalwire.com/docs or requesting it with the HTTP header `Accept: text/markdown`. The root index at https://signalwire.com/docs/llms.txt lists the available documentation indexes.

# registerSipUsername

> Register a specific SIP username to route calls to this agent.

[ref-agentbase]: /docs/server-sdks/reference/typescript/agents/agent-base

Register a specific SIP username that should be routed to this agent.

## **Parameters**

**`username`** `string` — required

SIP username to register for this agent.

---

## **Returns**

[`AgentBase`][ref-agentbase] -- Returns `this` for method chaining.

## **Example**

```typescript {6}
import { AgentBase } from '@signalwire/sdk';

const agent = new AgentBase({ name: 'support', route: '/support' });
agent.setPromptText('You are a helpful assistant.');
agent.enableSipRouting();
agent.registerSipUsername('help-desk');
agent.registerSipUsername('customer-service');
await agent.serve();
```

> Register a specific SIP username to route calls to this agent.