MCP Client Plugin not working

[isqc]

I am trying to use an MCP tool from my AI agent. I have created an MCP server definition with my server's URL and API key. The server is running FastMCP v2.13.0.2. 

When I try to add the MCP tools to my AI agent, I get an error when the initialize call is made. The return code is 406 and the request body is:

{"method":"initialize","id":"448d1ae3974d7a10c69b341de053afba","jsonrpc":"2.0","params":{"capabiliti**body truncated**

I am using version 1.1.2 of the snc_mcp_client plugin. The previous version had issues managing the mcp session, so it only worked between the time when I defined the MCP server connection and until the first session expired. But now I can't even list the tools, because the initialize call itself fails! 

Has anyone actually gotten this plugin to work consistently?

[isqc · Accepted solution]

Finally the solution was to upgrade to the latest Zurich patch (patch 3), and that solved the issue!

[warren_chan]

Glad to hear that worked!

I am unsure of the change that specifically benefited your situation, but we do a better job of negotiating the headers in the later releases of MCP client. Our MCP client 2.0.0 should be out in December/January as well.