[v6.0] fix: missing streamed reasoning for Open Responses reasoning summary text events

.changeset/fuzzy-responses-reason.md

@@ -0,0 +1,5 @@
+---
+'@ai-sdk/open-responses': patch
+---
+
+Stream Open Responses reasoning summary text deltas as reasoning output.

packages/open-responses/src/responses/__fixtures__/openai-reasoning-summary-text.1.chunks.txt

@@ -0,0 +1,6 @@
+{"type":"response.output_item.added","sequence_number":0,"output_index":0,"item":{"id":"rs_1","type":"reasoning","summary":[]}}
+{"type":"response.reasoning_summary_text.delta","sequence_number":1,"item_id":"rs_1","output_index":0,"summary_index":0,"delta":"Think"}
+{"type":"response.reasoning_summary_text.delta","sequence_number":2,"item_id":"rs_1","output_index":0,"summary_index":0,"delta":"ing."}
+{"type":"response.reasoning_summary_text.done","sequence_number":3,"item_id":"rs_1","output_index":0,"summary_index":0,"text":"Thinking."}
+{"type":"response.output_item.done","sequence_number":4,"output_index":0,"item":{"id":"rs_1","type":"reasoning","summary":[{"type":"summary_text","text":"Thinking."}]}}
+{"type":"response.completed","sequence_number":5,"response":{"id":"resp_1","status":"completed","incomplete_details":null,"usage":{"input_tokens":1,"output_tokens":1}}}

packages/open-responses/src/responses/open-responses-language-model.test.ts

@@ -645,6 +645,39 @@ describe('OpenResponsesLanguageModel', () => {
       });
     });
 
+    it('should stream reasoning summary text deltas', async () => {
+      prepareChunksFixtureResponse('openai-reasoning-summary-text.1');
+
+      const result = await createModel().doStream({
+        prompt: TEST_PROMPT,
+      });
+
+      const parts = await convertReadableStreamToArray(result.stream);
+
+      expect(
+        parts.filter(part => part.type.startsWith('reasoning')),
+      ).toStrictEqual([
+        {
+          type: 'reasoning-start',
+          id: 'rs_1',
+        },
+        {
+          type: 'reasoning-delta',
+          id: 'rs_1',
+          delta: 'Think',
+        },
+        {
+          type: 'reasoning-delta',
+          id: 'rs_1',
+          delta: 'ing.',
+        },
+        {
+          type: 'reasoning-end',
+          id: 'rs_1',
+        },
+      ]);
+    });
+
     describe('reasoning with tool call', () => {
       it('should stream reasoning and tool call content', async () => {
         prepareChunksFixtureResponse('lmstudio-tool-call.2');

packages/open-responses/src/responses/open-responses-language-model.ts

@@ -441,8 +441,9 @@ export class OpenResponsesLanguageModel implements LanguageModelV3 {
               });
               isActiveReasoning = true;
             } else if (
+              chunk.type === 'response.reasoning_summary_text.delta' ||
               (chunk as { type: string }).type ===
-              'response.reasoning_text.delta'
+                'response.reasoning_text.delta'
             ) {
               const reasoningChunk = chunk as {
                 item_id: string;

packages/zai/src/zai-provider.test.ts

@@ -1,6 +1,7 @@
 import { afterEach, describe, expect, it, vi } from 'vitest';
 import { ZaiChatLanguageModel } from './zai-chat-language-model';
 import { createZai } from './zai-provider';
+import { VERSION } from './version';
 
 const TEST_PROMPT = [
   {
@@ -61,7 +62,7 @@ describe('createZai', () => {
     );
     const headers = new Headers(fetch.mock.calls[0][1].headers);
     expect(headers.get('authorization')).toBe('Bearer test-key');
-    expect(headers.get('user-agent')).toContain('ai-sdk/zai/1.0.0');
+    expect(headers.get('user-agent')).toContain(`ai-sdk/zai/${VERSION}`);
   });
 
   it('reads the API key from ZAI_API_KEY by default', async () => {