fix(core): disable qwen json response format

Author: EAGzzyCSL

packages/core/src/ai-model/models/qwen.ts

@@ -9,7 +9,6 @@ import type {
   ChatCompletionParamsResult,
   ModelAdapterDefinition,
 } from './types';
-import { isLocateIntent } from './utils/intent';
 
 const defaultBboxSize = 20;
 
@@ -68,9 +67,11 @@ const buildQwenChatCompletionParams = (
 
   // Alibaba Cloud Model Studio JSON mode:
   // https://help.aliyun.com/zh/model-studio/json-mode
-  if (isLocateIntent(input.intent)) {
-    commonOverrideConfig.response_format = { type: 'json_object' };
-  }
+  // Observed in qwen3.6 grounding runs: enabling this can make the model
+  // return only ["bbox_2d"] without coordinates.
+  // if (isLocateIntent(input.intent)) {
+  //   commonOverrideConfig.response_format = { type: 'json_object' };
+  // }
 
   const modelSpecificConfig: Record<string, unknown> = {};
 

packages/core/tests/unit-test/model-adapter/qwen.test.ts

@@ -298,18 +298,6 @@ describe('qwen model adapter', () => {
     });
   });
 
-  it('uses json_object response format for qwen3 locate intent', () => {
-    const qwen3VlResult =
-      qwen3VlAdapter.chatCompletion.buildChatCompletionParams({
-        intent: 'default',
-        userConfig: {},
-      });
-
-    expect(qwen3VlResult.config.response_format).toEqual({
-      type: 'json_object',
-    });
-  });
-
   it('normalizes actual-pixel bbox coordinates for qwen2.5-vl', () => {
     const locateAdapter = qwen25Adapter.locate;
     expect(locateAdapter.kind).toBe('standard');