registerRoutingCallback

Register a callback for dynamic request routing. When a request arrives at the specified path, the callback inspects the POST body and decides whether to route the request to a different endpoint (via HTTP 307 redirect) or let normal SWML serving continue. Commonly used for SIP-based routing where the destination depends on the incoming SIP URI.

A Hono endpoint is registered immediately for the specified path, serving both GET and POST.

Unlike the Python SDK, the TypeScript RoutingCallback receives only the parsed request body — not the underlying Request object. If you need access to headers or URL, use asRouter() and install custom middleware on the Hono app directly.

Parameters

callbackFn

RoutingCallbackRequired

A function that receives the parsed JSON request body. Return a route string to redirect the request (HTTP 307 preserves the POST method and body), or null / undefined to continue with normal SWML document serving. May be async.

path

stringDefaults to /sip

The URL path where this routing endpoint is created. The path is normalized: a leading / is added if missing, trailing slashes are stripped.

Returns

void

Example

Routing callback with SIP username

1 import { SWMLService } from '@signalwire/sdk';
2 
3 const service = new SWMLService({ name: 'sip-router', route: '/' });
4 
5 function routeSipCall(body: Record<string, unknown>): string | null {
6   const username = SWMLService.extractSipUsername(body);
7   if (username === 'sales') return '/agents/sales';
8   if (username === 'support') return '/agents/support';
9   return null; // Default handling
10 }
11 
12 service.addVerb('answer', {});
13 service.registerRoutingCallback(routeSipCall, '/sip');
14 
15 await service.serve();