SEO Tools MCP Server

# Bug Fix: server.callTool is not a function ## Problem External MCP clients were receiving this error when calling tools via the HTTP bridge: ```json { "error": { "code": -32603, "message": "server.callTool is not a function" } } ``` ## Root Cause The HTTP bridge in `src/server-http.ts` (line 207) was attempting to call `server.callTool()` on the McpServer instance: ```typescript const result = await (server as any).callTool(params.name, params.arguments || {}); ``` However, the `@modelcontextprotocol/sdk` McpServer class doesn't expose a `callTool()` method. Tool handlers are registered internally via `server.tool()` but cannot be invoked directly through the server object. ## Solution ### 1. Enhanced Tool Registry (`src/api/tools.ts`) Modified the `toolRegistry` to store both metadata AND handler functions: ```typescript // Before: Only stored metadata toolRegistry.set(name, { name, description: '', inputSchema: schema }); // After: Stores metadata AND handler toolRegistry.set(name, { name, description: '', inputSchema: schema, handler: toolHandler // Added handler function }); ``` ### 2. HTTP Bridge Tool Calling (`src/server-http.ts`) Changed from attempting to call a non-existent method to directly invoking the handler from the registry: ```typescript // Before: Tried to call non-existent method const result = await (server as any).callTool(params.name, params.arguments || {}); // After: Call handler directly from registry const tool = toolRegistry.get(params.name); if (!tool || !tool.handler) { return res.status(404).json({ jsonrpc: '2.0', error: { code: -32601, message: `Tool not found: ${params.name}` }, id }); } const result = await tool.handler(params.arguments || {}, {}); ``` ## Files Modified 1. `src/api/tools.ts` - Enhanced toolRegistry to store handlers 2. `src/server-http.ts` - Fixed tool invocation in HTTP bridge ## Testing After the fix, rebuild the project: ```bash npm run build ``` Then redeploy: ```bash # For Cloud Run gcloud run deploy dataforseo-mcp-server \ --region=us-central1 \ --source=. \ --allow-unauthenticated # Or test locally npm run start:http ``` ## Verification Test the HTTP endpoint with a tools/call request: ```bash curl -X POST http://localhost:8080/mcp \ -H "Content-Type: application/json" \ -d '{ "jsonrpc": "2.0", "method": "tools/call", "params": { "name": "dataforseo_serp_google", "arguments": { "keyword": "test", "location_name": "United States" } }, "id": 1 }' ``` Expected response: JSON result with tool execution data, not an error about `callTool`. ## Impact - ✅ HTTP bridge now properly routes tool calls - ✅ External MCP clients can successfully invoke tools - ✅ No breaking changes to stdio MCP server functionality - ✅ Tool handlers are reused between stdio and HTTP transports ## Related - MCP SDK: `@modelcontextprotocol/sdk` v1.19.1 - HTTP Server: Express.js - JSON-RPC 2.0 protocol compliance