MoluAbi MCP Server

# MCP Server Initialization Diagnostic - URGENT Hi team, We have a **critical integration issue** with our MCP server and ATXP SDK. A user has provided detailed diagnostics showing that while our free tier works perfectly, the ATXP integration is failing due to missing MCP protocol methods. ## Current Issue Summary **What's Working ✅** - Free tier mode: Direct HTTP calls to `/mcp/call` work perfectly - All tools execute successfully (list_agents, create_agent, prompt_agent, etc.) - API authentication works correctly - Server returns proper JSON responses **What's Failing ❌** - ATXP SDK cannot establish connection to our server - **Critical Error:** `"Method not found: initialize"` when SDK tries to connect - ATXP endpoint at `/atxp` doesn't support MCP lifecycle methods ## Technical Details from User Testing The user tested both endpoints: **✅ This works (free tier):** ```bash curl -X POST https://moluabi-mcp-server.replit.app/mcp/call \ -d '{"name":"list_agents","arguments":{"apiKey":"mab_..."}}' # Returns: agents list successfully ``` **❌ This fails (ATXP endpoint):** ```bash curl -X POST https://moluabi-mcp-server.replit.app/atxp \ -d '{"jsonrpc":"2.0","method":"initialize","params":{},"id":1}' # Returns: {"error":{"code":-32601,"message":"Method not found: initialize"}} ``` **Key Finding:** Our `/atxp` endpoint accepts `tools/call` but **NOT** `initialize` ## Critical Issue: Missing MCP Protocol Methods **The ATXP SDK Flow:** 1. SDK connects to `https://moluabi-mcp-server.replit.app/atxp` 2. Sends JSON-RPC initialize request: `{"jsonrpc":"2.0","method":"initialize","params":{...},"id":0}` 3. **Our server responds:** `{"jsonrpc":"2.0","error":{"code":-32601,"message":"Method not found: initialize"},"id":0}` 4. SDK fails and cannot proceed to tool calls **Question 1:** Why does our `/atxp` endpoint not support the `initialize` method? - Does our `/atxp` endpoint implement full MCP protocol or just tool calls? - Is there a difference in how we handle `/mcp/call` vs `/atxp` endpoints? - **Critical:** The ATXP SDK expects full MCP JSON-RPC protocol before making any tool calls ## Endpoint Architecture Investigation **Question 2:** Please map out our current endpoint structure: - **`/mcp/call`** - What does this endpoint do? (Works perfectly with direct calls) - **`/atxp`** - What does this endpoint do? (Accepts `tools/call` but not `initialize`) - Are these two separate implementations or should they be unified? **Question 3:** MCP Protocol Compliance per Endpoint: - Does `/mcp/call` support full MCP JSON-RPC protocol? - Does `/atxp` support full MCP JSON-RPC protocol? - **Key Finding:** `/atxp` accepts `tools/call` but rejects `initialize` - this suggests partial MCP implementation ## Required MCP Methods for ATXP Integration **Question 4:** Based on user testing, our `/atxp` endpoint needs to support these JSON-RPC methods: **Missing (Critical):** - [ ] `initialize` - **FAILING** with "Method not found" error - [ ] `list_tools` - SDK needs to discover available tools - [ ] `list_resources` - If we have any resources - [ ] `list_prompts` - If we have any prompts **Partially Working:** - [?] `tools/call` - User confirms this method exists but requires ATXP auth **Question 5:** Do we properly implement session management? - Do we generate and return a session ID in the `Mcp-Session-Id` HTTP header during initialization? - Do we validate this session ID on subsequent requests? - Do we return a 404 when a session expires to trigger re-initialization? **If missing:** Implement session tracking using an in-memory store (Map/object) that associates session IDs with client connections. ## Transport Configuration **Question 6:** What transport method does our `/atxp` endpoint use? - The user is making HTTP POST requests to `/atxp` - ATXP SDK expects Streamable HTTP transport - **Verify:** Is our `/atxp` endpoint properly configured for Streamable HTTP MCP transport? ## Authentication Layer Analysis **Question 7:** Authentication behavior differences: - **Free tier (`/mcp/call`):** Works with API key in request body - **ATXP endpoint (`/atxp`):** Returns "Payment required - ATXP authentication missing" - **Critical:** How should ATXP authentication integrate with MCP protocol initialization? ## Core MCP Protocol Implementation **Question 8:** Based on the user's error, please verify we implement these methods **specifically on the `/atxp` endpoint**: - [ ] `initialize` - **CRITICAL:** Currently returns -32601 "Method not found" - [ ] `list_tools` - Required for ATXP SDK to discover our tools - [ ] `list_resources` - Return available resources (if we have any) - [ ] `list_prompts` - Return available prompts (if we have any) - [ ] `tools/call` - User confirmed this exists but needs ATXP auth - [ ] `read_resource` - Serve resource content (if applicable) ## Server Metadata and Capabilities **Question 9:** For the `/atxp` endpoint, do we return proper initialization response? When `initialize` is called, we should return: ```json { "jsonrpc": "2.0", "result": { "name": "moluabi-mcp-server", "version": "1.0.0", "capabilities": { "tools": { "list_tools": true }, "resources": {}, "prompts": {} } }, "id": 0 } ``` **Instead we're returning:** ```json {"jsonrpc":"2.0","error":{"code":-32601,"message":"Method not found: initialize"},"id":0} ``` ## Immediate Testing Requirements **Question 10:** Can you test these specific curl commands on our server? **Test 1 - Initialize (Currently Failing):** ```bash curl -X POST https://moluabi-mcp-server.replit.app/atxp \ -d '{"jsonrpc":"2.0","method":"initialize","params":{},"id":1}' ``` **Expected:** Success response with server capabilities **Current:** `{"error":{"code":-32601,"message":"Method not found: initialize"}}` **Test 2 - List Tools (Unknown Status):** ```bash curl -X POST https://moluabi-mcp-server.replit.app/atxp \ -d '{"jsonrpc":"2.0","method":"list_tools","params":{},"id":2}' ``` **Test 3 - Tool Call (Partially Working):** ```bash curl -X POST https://moluabi-mcp-server.replit.app/atxp \ -d '{"jsonrpc":"2.0","method":"tools/call","params":{"name":"list_agents","arguments":{"apiKey":"mab_..."}},"id":3}' ``` **Expected:** Tool execution **Current:** "Payment required - ATXP authentication missing" (shows method exists) ## Root Cause Analysis Questions **Question 11:** Implementation Architecture: - Are we using the official MCP SDK for the `/atxp` endpoint? - Did we implement `/atxp` as a custom API that only partially follows MCP protocol? - **Critical:** Why does `/mcp/call` work but `/atxp` missing `initialize`? **Question 12:** Integration Pattern: - Is `/atxp` supposed to be a full MCP server or just a tool execution endpoint? - Should we unify both endpoints to use the same MCP implementation? - Can we make `/atxp` inherit all MCP protocol methods from `/mcp/call`? ## Immediate Action Items **Priority 1 (Blocking ATXP Integration):** 1. **Fix `/atxp` endpoint** to respond to `initialize` method 2. **Add `list_tools`** method to `/atxp` endpoint 3. **Test with provided curl commands** to verify MCP protocol compliance **Priority 2 (Validation):** 4. Run MCP Inspector against `/atxp` endpoint 5. Verify session management works with ATXP authentication 6. Document the difference between `/mcp/call` and `/atxp` endpoints ## Testing Validation After implementing fixes, please test: ```bash # Should work after fix: curl -X POST https://moluabi-mcp-server.replit.app/atxp \ -d '{"jsonrpc":"2.0","method":"initialize","params":{},"id":1}' # Should return our tools: curl -X POST https://moluabi-mcp-server.replit.app/atxp \ -d '{"jsonrpc":"2.0","method":"list_tools","params":{},"id":2}' ``` **Bottom Line:** The ATXP SDK expects full MCP JSON-RPC protocol compliance on the `/atxp` endpoint, but we're only implementing `tools/call`. We need to add the missing MCP lifecycle methods (`initialize`, `list_tools`, etc.) to make ATXP integration work. Please let me know your findings for each question, and we can troubleshoot any missing pieces together. Thanks!