feat: add extra_body support for OpenAI-compatible providers

Add extra_body configuration option to model.generationConfig for passing
custom parameters to OpenAI-compatible API request bodies.

- Add extra_body to ContentGeneratorConfig type
- Add extra_body to MODEL_GENERATION_CONFIG_FIELDS and ModelGenerationConfig
- Implement extra_body merging in DefaultOpenAICompatibleProvider
- Implement extra_body merging in DashScopeOpenAICompatibleProvider
- Update documentation with examples and provider compatibility notes
- Note: This feature is only for OpenAI-compatible providers (openai, qwen-oauth)

Resolves #1647
Resolves #1644

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

packages/core/src/core/contentGenerator.ts

@@ -93,6 +93,8 @@ export type ContentGeneratorConfig = {
   schemaCompliance?: 'auto' | 'openapi_30';
   // Custom HTTP headers to be sent with requests
   customHeaders?: Record<string, string>;
+  // Extra body parameters to be merged into the request body
+  extra_body?: Record<string, unknown>;
 };
 
 // Keep the public ContentGeneratorConfigSources API, but reuse the generic

packages/core/src/core/openaiContentGenerator/provider/dashscope.test.ts

@@ -929,5 +929,71 @@ describe('DashScopeOpenAICompatibleProvider', () => {
       expect(result.max_tokens).toBe(65536); // Should be limited
       expect(result.stream).toBe(true); // Streaming should be preserved
     });
+
+    it('should merge extra_body into the request', () => {
+      const providerWithExtraBody = new DashScopeOpenAICompatibleProvider(
+        {
+          ...mockContentGeneratorConfig,
+          extra_body: {
+            custom_param: 'custom_value',
+            nested: { key: 'value' },
+          },
+        },
+        mockCliConfig,
+      );
+
+      const request: OpenAI.Chat.ChatCompletionCreateParams = {
+        model: 'qwen3-coder-plus',
+        messages: [{ role: 'user', content: 'Hello' }],
+      };
+
+      const result = providerWithExtraBody.buildRequest(
+        request,
+        'test-prompt-id',
+      );
+
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      expect((result as any).custom_param).toBe('custom_value');
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      expect((result as any).nested).toEqual({ key: 'value' });
+    });
+
+    it('should merge extra_body into vision model requests', () => {
+      const providerWithExtraBody = new DashScopeOpenAICompatibleProvider(
+        {
+          ...mockContentGeneratorConfig,
+          extra_body: {
+            custom_param: 'custom_value',
+          },
+        },
+        mockCliConfig,
+      );
+
+      const request: OpenAI.Chat.ChatCompletionCreateParams = {
+        model: 'qwen-vl-max',
+        messages: [{ role: 'user', content: 'Hello' }],
+      };
+
+      const result = providerWithExtraBody.buildRequest(
+        request,
+        'test-prompt-id',
+      );
+
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      expect((result as any).custom_param).toBe('custom_value');
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      expect((result as any).vl_high_resolution_images).toBe(true);
+    });
+
+    it('should not include extra_body when not configured', () => {
+      const request: OpenAI.Chat.ChatCompletionCreateParams = {
+        model: 'qwen3-coder-plus',
+        messages: [{ role: 'user', content: 'Hello' }],
+      };
+
+      const result = provider.buildRequest(request, 'test-prompt-id');
+
+      expect(result).not.toHaveProperty('custom_param');
+    });
   });
 });

packages/core/src/core/openaiContentGenerator/provider/dashscope.ts

@@ -124,6 +124,8 @@ export class DashScopeOpenAICompatibleProvider
       request.model,
     );
 
+    const extraBody = this.contentGeneratorConfig.extra_body;
+
     if (this.isVisionModel(request.model)) {
       return {
         ...requestWithTokenLimits,
@@ -132,6 +134,7 @@ export class DashScopeOpenAICompatibleProvider
         ...(this.buildMetadata(userPromptId) || {}),
         /* @ts-expect-error dashscope exclusive */
         vl_high_resolution_images: true,
+        ...(extraBody ? extraBody : {}),
       } as OpenAI.Chat.ChatCompletionCreateParams;
     }
 
@@ -140,6 +143,7 @@ export class DashScopeOpenAICompatibleProvider
       messages,
       ...(tools ? { tools } : {}),
       ...(this.buildMetadata(userPromptId) || {}),
+      ...(extraBody ? extraBody : {}),
     } as OpenAI.Chat.ChatCompletionCreateParams;
   }
 

packages/core/src/core/openaiContentGenerator/provider/default.test.ts

@@ -261,5 +261,48 @@ describe('DefaultOpenAICompatibleProvider', () => {
       // Result should be a different object
       expect(result).not.toBe(originalRequest);
     });
+
+    it('should merge extra_body into the request', () => {
+      const providerWithExtraBody = new DefaultOpenAICompatibleProvider(
+        {
+          ...mockContentGeneratorConfig,
+          extra_body: {
+            custom_param: 'custom_value',
+            nested: { key: 'value' },
+          },
+        } as ContentGeneratorConfig,
+        mockCliConfig,
+      );
+
+      const originalRequest: OpenAI.Chat.ChatCompletionCreateParams = {
+        model: 'gpt-4',
+        messages: [{ role: 'user', content: 'Hello' }],
+        temperature: 0.7,
+      };
+
+      const result = providerWithExtraBody.buildRequest(
+        originalRequest,
+        'prompt-id',
+      );
+
+      expect(result).toEqual({
+        ...originalRequest,
+        custom_param: 'custom_value',
+        nested: { key: 'value' },
+      });
+    });
+
+    it('should not include extra_body when not configured', () => {
+      const originalRequest: OpenAI.Chat.ChatCompletionCreateParams = {
+        model: 'gpt-4',
+        messages: [{ role: 'user', content: 'Hello' }],
+        temperature: 0.7,
+      };
+
+      const result = provider.buildRequest(originalRequest, 'prompt-id');
+
+      expect(result).toEqual(originalRequest);
+      expect(result).not.toHaveProperty('custom_param');
+    });
   });
 });

packages/core/src/core/openaiContentGenerator/provider/default.ts

@@ -64,9 +64,11 @@ export class DefaultOpenAICompatibleProvider
     request: OpenAI.Chat.ChatCompletionCreateParams,
     _userPromptId: string,
   ): OpenAI.Chat.ChatCompletionCreateParams {
+    const extraBody = this.contentGeneratorConfig.extra_body;
     // Default provider doesn't need special enhancements, just pass through all parameters
     return {
       ...request, // Preserve all original parameters including sampling params
+      ...(extraBody ? extraBody : {}),
     };
   }
 

packages/core/src/models/constants.ts

@@ -26,6 +26,7 @@ export const MODEL_GENERATION_CONFIG_FIELDS = [
   'schemaCompliance',
   'reasoning',
   'customHeaders',
+  'extra_body',
 ] as const satisfies ReadonlyArray<keyof ContentGeneratorConfig>;
 
 /**

packages/core/src/models/types.ts

@@ -32,6 +32,7 @@ export type ModelGenerationConfig = Pick<
   | 'schemaCompliance'
   | 'reasoning'
   | 'customHeaders'
+  | 'extra_body'
 >;
 
 /**