MCP server is not working

[its-dibo]

Current Behavior

I setup nx-mcp and started the server

.vscode/mcp.json

{
  "servers": {
    "nx-mcp": {
      "type": "http",
      "url": "http://localhost:9436/mcp"
    }
  }
}

to test the server, I opened "ttp://localhost:9436/mcp" in the browser

{"jsonrpc":"2.0","error":{"code":-32000,"message":"Method not allowed."},"id":null}

Then, I opened the copilot chat and entered a basic prompt @nx describe the workspace, the response is Request Failed: 400 Bad Request

I also tried to run nx graph before using the prompt

Expected Behavior

The MCP can response to the copilot prompts

GitHub Repo

No response

Steps to Reproduce

1. setup MCP
2. start the MCP server
3. run nx graph
4. ask copilot about the nx workspace using a basic propmpt @nx describe the workspace

Nx Report

Node           : 22.12.0
OS             : linux-x64
Native Target  : x86_64-linux
pnpm           : 9.15.0

nx (global)  : 21.2.0
nx           : 21.2.0
@nx/js       : 21.2.0
@nx/jest     : 21.2.0
@nx/eslint   : 21.2.0
typescript   : 5.8.3
---------------------------------------
Registered Plugins:
@nx/js/typescript
@nx/jest/plugin
@nx/jest/plugin
---------------------------------------
Cache Usage: 49.24 MB / 46.73 GB

Failure Logs

Package Manager Version

No response

Operating System

• macOS
• Linux
• Windows
• Other (Please specify)

Additional Information

No response

[MaxKless]

Hi, thanks for the report!
I think you're confusing two concepts: the MCP server & the chat participant. To use the MCP server, you don't have to type @nx, just start copilot in agent mode and it will use the tools automatically. You can click the little tool icon below the chat input to see all available mcp servers & tools.

The @nx chat participant error is legit tho, I'll close this issue in favor of nrwl/nx-console#2446 which already reported this.