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# registerRoutingCallback

> Register a callback for dynamic request routing based on SIP URIs or POST data.

[enable-sip-routing]: /docs/server-sdks/reference/typescript/agents/agent-base/enable-sip-routing

[extract-sip-username]: /docs/server-sdks/reference/typescript/agents/agent-base/extract-sip-username

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

Register a callback for dynamic request routing. When a request arrives at
`path`, the callback inspects the POST body and decides whether to redirect the
request to a different route or let normal SWML serving continue.

This is primarily used for SIP-based routing where the destination depends on
the incoming SIP URI. For routing on agent name alone, use
[`enableSipRouting()`][enable-sip-routing] instead.

## **Parameters**

**`callback`** `RoutingCallback` — required

Receives the parsed request body and, optionally, the request headers.
Return a route string to redirect the request there (HTTP 307, preserving
the POST body), or return `null` or `undefined` to serve this agent's own
SWML.

---

**`path`** `string` — default: /sip

HTTP path where the routing endpoint is registered. Normalized to start with
`/`, with trailing slashes stripped.

---

## **Returns**

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

## **Example**

```typescript {6-11}
import { AgentBase } from '@signalwire/sdk';

const agent = new AgentBase({ name: 'router', route: '/' });
agent.setPromptText('You are a helpful assistant.');

agent.registerRoutingCallback((body) => {
  const username = AgentBase.extractSipUsername(body);
  if (username === 'sales') return '/agents/sales';
  if (username === 'support') return '/agents/support';
  return null;
}, '/sip');

await agent.run();
```

> Register a callback for dynamic request routing based on SIP URIs or POST data.