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?

[warren_chan]

Agree, my suggestion was more from the Postman side. It must work in Postman before you try in ServiceNow.

Claude Desktop is another choice, but is less of a direct comparison test since it can negotiate the headers better than Postman.

[angelmarquez]

Any update on this? We are stuck setting up the MCP, all our AI Agents are expecting to interact with the MCP when new configs are updated or created in the instance.

[warren_chan]

Where are you stuck on setting up MCP?

[angelmarquez]

Im receiving the following error: Unable to fetch the tools for the MCP Server. Configured MCP server with OAUTH v2.1 and API Key, but still not working, even tried the sample Github repo from documentation and not working. Plugins and pre-requisites are OK. 

[warren_chan]

Take a look at this thread that Victor had posted. These are proven MCP servers that we know work with our MCP client. Worth a try if you are trying to isolate a problem:

https://www.servicenow.com/community/now-assist-articles/try-the-now-assist-ai-agent-mcp-client-with...