fix(realtime): honor the selected WebSocket session target

src/beta/realtime/internal-base.ts

@@ -197,6 +197,11 @@ export function buildRealtimeURL(
   }
 
   url.protocol = 'wss';
+  if (!azure) {
+    url.searchParams.delete('model');
+    url.searchParams.delete('intent');
+    url.searchParams.delete('call_id');
+  }
   // Sideband control connections attach to an existing call via `call_id`.
   if (azure) {
     if (hasCallID) {

src/realtime/internal-base.ts

@@ -299,6 +299,9 @@ export function buildRealtimeURL(
     url.search = '';
   } else {
     url.pathname += url.pathname.endsWith('/') ? 'realtime' : '/realtime';
+    url.searchParams.delete('model');
+    url.searchParams.delete('intent');
+    url.searchParams.delete('call_id');
   }
 
   url.hash = '';

tests/realtime-wire-lifecycle.test.ts

@@ -69,6 +69,59 @@ afterAll(async () => {
   await stopped;
 });
 
+describe.each([StableWS, StableNative])('GA Realtime target selection (%s)', (Realtime) => {
+  test.each([
+    { target: { model: 'chosen-model' }, selected: ['model', 'chosen-model'] },
+    { target: { intent: 'transcription' }, selected: ['intent', 'transcription'] },
+    { target: { callID: 'call_test_+/&' }, selected: ['call_id', 'call_test_+/&'] },
+  ] satisfies { target: RealtimeConnectionConfig; selected: string[] }[])(
+    'replaces stale base URL targets with $selected',
+    async ({ target, selected }) => {
+      const incoming = once(peers, 'connection');
+      const client = new OpenAI({
+        baseURL: `${baseURL}?model=old&model=other&intent=old&call_id=old&tenant=one`,
+        apiKey: 'ek_synthetic_wire',
+      });
+      const realtime = new Realtime({ ...target, options: settings.options }, client);
+      const opened = rawEvent(realtime.socket, 'open');
+      try {
+        const [, request] = await incoming;
+        await opened;
+        const url = new URL(request.url, baseURL);
+        expect([...url.searchParams]).toEqual([['tenant', 'one'], selected]);
+      } finally {
+        const closed = rawEvent(realtime.socket, 'close');
+        realtime.close();
+        await closed;
+      }
+    },
+  );
+});
+
+describe.each([BetaWS, BetaNative])('beta Realtime target selection (%s)', (Realtime) => {
+  test.each([
+    { target: { model: 'chosen-model' }, selected: ['model', 'chosen-model'] },
+    { target: { callID: 'call_test_+/&' }, selected: ['call_id', 'call_test_+/&'] },
+  ])('replaces stale base URL targets with $selected', async ({ target, selected }) => {
+    const incoming = once(peers, 'connection');
+    const client = new OpenAI({
+      baseURL: `${baseURL}?model=old&model=other&intent=old&call_id=old&call_id=other&tenant=one`,
+      apiKey: 'ek_synthetic_wire',
+    });
+    const realtime = new Realtime({ ...target, options: settings.options }, client);
+    const opened = rawEvent(realtime.socket, 'open');
+    try {
+      const [, request] = await incoming;
+      await opened;
+      expect([...new URL(request.url, baseURL).searchParams]).toEqual([['tenant', 'one'], selected]);
+    } finally {
+      const closed = rawEvent(realtime.socket, 'close');
+      realtime.close();
+      await closed;
+    }
+  });
+});
+
 describe.each([
   { label: 'GA ws', Realtime: StableWS, native: false, beta: false },
   { label: 'beta ws', Realtime: BetaWS, native: false, beta: true },