feat(research): Implement research APIs.

ts/provider.openai.ts

@@ -233,52 +233,37 @@ export class OpenAiProvider extends MultiModalModel {
   }
 
   public async research(optionsArg: ResearchOptions): Promise<ResearchResponse> {
-    // Determine which model to use based on search depth
+    // Determine which model to use - Deep Research API requires specific models
     let model: string;
     if (optionsArg.searchDepth === 'deep') {
       model = this.options.researchModel || 'o4-mini-deep-research-2025-06-26';
     } else {
-      model = this.options.chatModel || 'gpt-5-mini';
+      // For basic/advanced, still use deep research models if web search is needed
+      if (optionsArg.includeWebSearch) {
+        model = this.options.researchModel || 'o4-mini-deep-research-2025-06-26';
+      } else {
+        model = this.options.chatModel || 'gpt-5-mini';
+      }
     }
 
-    // Prepare the request parameters
+    const systemMessage = 'You are a research assistant. Provide comprehensive answers with citations and sources when available.';
+
+    // Prepare request parameters using Deep Research API format
     const requestParams: any = {
       model,
-      messages: [
-        {
-          role: 'system',
-          content: 'You are a research assistant. Provide comprehensive answers with citations and sources when available.'
-        },
-        {
-          role: 'user',
-          content: optionsArg.query
-        }
-      ],
-      temperature: 0.7
+      instructions: systemMessage,
+      input: optionsArg.query
     };
 
-    // Add web search tools if requested
+    // Add web search tool if requested
     if (optionsArg.includeWebSearch || optionsArg.searchDepth === 'deep') {
       requestParams.tools = [
         {
-          type: 'function',
-          function: {
-            name: 'web_search',
-            description: 'Search the web for information',
-            parameters: {
-              type: 'object',
-              properties: {
-                query: {
-                  type: 'string',
-                  description: 'The search query'
-                }
-              },
-              required: ['query']
-            }
-          }
+          type: 'web_search_preview',
+          search_context_size: optionsArg.searchDepth === 'deep' ? 'high' :
+                              optionsArg.searchDepth === 'advanced' ? 'medium' : 'low'
         }
       ];
-      requestParams.tool_choice = 'auto';
     }
 
     // Add background flag for deep research
@@ -287,14 +272,36 @@ export class OpenAiProvider extends MultiModalModel {
     }
 
     try {
-      // Execute the research request
-      const result = await this.openAiApiClient.chat.completions.create(requestParams);
+      // Execute the research request using Deep Research API
+      const result = await this.openAiApiClient.responses.create(requestParams);
 
-      // Extract the answer
-      const answer = result.choices[0].message.content || '';
-
-      // Parse sources from the response (OpenAI often includes URLs in markdown format)
+      // Extract the answer from output items
+      let answer = '';
       const sources: Array<{ url: string; title: string; snippet: string }> = [];
+      const searchQueries: string[] = [];
+
+      // Process output items
+      for (const item of result.output || []) {
+        // Extract message content
+        if (item.type === 'message' && 'content' in item) {
+          const messageItem = item as any;
+          for (const contentItem of messageItem.content || []) {
+            if (contentItem.type === 'output_text' && 'text' in contentItem) {
+              answer += contentItem.text;
+            }
+          }
+        }
+
+        // Extract web search queries
+        if (item.type === 'web_search_call' && 'action' in item) {
+          const searchItem = item as any;
+          if (searchItem.action && searchItem.action.type === 'search' && 'query' in searchItem.action) {
+            searchQueries.push(searchItem.action.query);
+          }
+        }
+      }
+
+      // Parse sources from markdown links in the answer
       const urlRegex = /\[([^\]]+)\]\(([^)]+)\)/g;
       let match: RegExpExecArray | null;
 
@@ -302,27 +309,10 @@ export class OpenAiProvider extends MultiModalModel {
         sources.push({
           title: match[1],
           url: match[2],
-          snippet: '' // OpenAI doesn't provide snippets in standard responses
+          snippet: ''
         });
       }
 
-      // Extract search queries if tools were used
-      const searchQueries: string[] = [];
-      if (result.choices[0].message.tool_calls) {
-        for (const toolCall of result.choices[0].message.tool_calls) {
-          if ('function' in toolCall && toolCall.function.name === 'web_search') {
-            try {
-              const args = JSON.parse(toolCall.function.arguments);
-              if (args.query) {
-                searchQueries.push(args.query);
-              }
-            } catch (e) {
-              // Ignore parsing errors
-            }
-          }
-        }
-      }
-
       return {
         answer,
         sources,