fix(agents-realtime): preserve assistant audio transcripts in history updates

.changeset/fresh-brooms-relax.md

@@ -0,0 +1,5 @@
+---
+'@openai/agents-realtime': patch
+---
+
+Preserve assistant audio transcripts when realtime updates omit content.

packages/agents-realtime/src/utils.ts

@@ -151,7 +151,8 @@ export function removeAudioFromContent(
     return {
       ...item,
       content: item.content.map((entry) => {
-        if ((entry as any).type === 'output_audio') {
+        const entryType = (entry as any).type;
+        if (entryType === 'output_audio' || entryType === 'audio') {
           return {
             ...entry,
             audio: null,
@@ -192,27 +193,43 @@ function preserveAssistantAudioTranscripts(
     return incoming;
   }
 
+  if (incoming.content.length === 0 && existing.content.length > 0) {
+    return {
+      ...incoming,
+      content: existing.content,
+    };
+  }
+
   const mergedContent = incoming.content.map((entry, index) => {
-    if (entry.type !== 'output_audio') {
+    const entryType = (entry as any).type;
+    if (entryType !== 'output_audio' && entryType !== 'audio') {
       return entry;
     }
 
+    const entryTranscript = (entry as any).transcript;
     const transcriptMissing =
-      typeof entry.transcript !== 'string' || entry.transcript.length === 0;
+      typeof entryTranscript !== 'string' || entryTranscript.length === 0;
     if (!transcriptMissing) {
       return entry;
     }
 
     const previousEntry = existing.content[index];
-    if (
-      previousEntry &&
-      previousEntry.type === 'output_audio' &&
-      typeof previousEntry.transcript === 'string' &&
-      previousEntry.transcript.length > 0
-    ) {
+    if (!previousEntry) {
+      return entry;
+    }
+
+    const previousType = (previousEntry as any).type;
+    const previousTranscript =
+      (previousType === 'output_audio' || previousType === 'audio') &&
+      typeof (previousEntry as any).transcript === 'string' &&
+      (previousEntry as any).transcript.length > 0
+        ? (previousEntry as any).transcript
+        : null;
+
+    if (previousTranscript) {
       return {
-        ...entry,
-        transcript: previousEntry.transcript,
+        ...(entry as any),
+        transcript: previousTranscript,
       };
     }
 

packages/agents-realtime/test/utils.test.ts

@@ -195,6 +195,33 @@ describe('realtime utils', () => {
     }
   });
 
+  it('preserves assistant audio transcript when incoming content is empty', () => {
+    const transcript = 'voice transcript';
+    const history: RealtimeMessageItem[] = [
+      {
+        itemId: '4',
+        type: 'message',
+        role: 'assistant',
+        status: 'completed',
+        content: [{ type: 'audio', transcript }],
+      } as RealtimeMessageItem,
+    ];
+
+    const incoming: RealtimeMessageItem = {
+      itemId: '4',
+      type: 'message',
+      role: 'assistant',
+      status: 'in_progress',
+      content: [],
+    } as RealtimeMessageItem;
+
+    const updated = updateRealtimeHistory(history, incoming, false);
+    const updatedMessage = updated[0] as RealtimeMessageItem;
+    const content = updatedMessage.content[0] as any;
+    expect(content.transcript).toBe(transcript);
+    expect(updatedMessage.status).toBe('in_progress');
+  });
+
   it('prefers new transcript value when provided', () => {
     const history: RealtimeMessageItem[] = [
       {
@@ -234,12 +261,22 @@ describe('realtime utils', () => {
       status: 'completed',
       content: [{ type: 'output_audio', audio: 'out', transcript: 'bye' }],
     };
+    const assistantAudioItem: RealtimeMessageItem = {
+      itemId: 'a2',
+      type: 'message',
+      role: 'assistant',
+      status: 'completed',
+      content: [{ type: 'audio', audio: 'out', transcript: 'bye' }],
+    } as RealtimeMessageItem;
     expect(
       (removeAudioFromContent(userItem).content[0] as any).audio,
     ).toBeNull();
     expect(
       (removeAudioFromContent(assistantItem).content[0] as any).audio,
     ).toBeNull();
+    expect(
+      (removeAudioFromContent(assistantAudioItem).content[0] as any).audio,
+    ).toBeNull();
   });
 
   it('hasWebRTCSupport detects window availability', () => {