MCP-Server not working

[luanpaschoal]

Hello, I'm trying to use MCP, but I can't:

Pycharm: MCP error -1: Connection closed

Cursor:

[clareliguori]

Hello, could you try debugging the server to see what the error is?

npx @modelcontextprotocol/inspector python -m strands_mcp_server

[salihgueler]

@luanpaschoal Cursor might expect you to have uv tool in your computer. Can you verify if it is installed and available globally (you can run "uv" in your terminal to check)?

If not, you can install it like it is explained here and try again.

[DennisTraub]

+1 to @salihgueler's recommendation.

If that doesn't fix it, you can further troubleshoot with the inspector.

Note that the command from @clareliguori will only work if you have downloaded and installed the MCP server manually.

If you haven't, try this instead (again, make sure uv is installed):

npx @modelcontextprotocol/inspector uvx strands-agents-mcp-server

[DennisTraub]

Note to @clareliguori and team:

While troubleshooting this issue, we discovered that even though the original problem likely had a different cause (missing uv installation), the documentation confusion made it much harder for us to reproduce and debug the problem.

The confusion appears to stem from there being two different names in play:

1. The package name: strands-agents-mcp-server, which is required for uv/pip to find and download the package from PyPI, as used in Inspector:

   npx @modelcontextprotocol/inspector uvx strands-agents-mcp-server

   and Q Dev CLI, Cursor, etc.:

   {
     "mcpServers": {
       "strands": {
         "command": "uvx",
         "args": ["strands-agents-mcp-server"]
       }
     }
   }

2. The script name: strands_mcp_server, which is only available when you're working with a local copy of the repo, as in:

   git clone https://github.com/strands-agents/mcp-server.git
   cd mcp-server
   python3 -m venv venv
   source venv/bin/activate
   pip3 install -e .
   npx @modelcontextprotocol/inspector python -m strands_mcp_server

I think there's opportunity for two improvements, both in the README:

1. Being explicit about uv as a prerequisite - This would help users avoid the original issue entirely
2. Adding a paragraph pointing to npx @modelcontextprotocol/inspector uvx strands-agents-mcp-server outside the "Server Development" section - This would help users who want to quickly test the MCP server without doing local development work

This should help prevent similar confusion for future users who are trying to troubleshoot MCP server issues.

[luanpaschoal]

Hello everyone, thanks for your attention.
Yes, I have uv installed (version 0.7.5), I'm using Windows 11.

When I opened the cursor the other day it worked, but in PyCharm the connection closed error persists. I increased the PyCharm timeout parameter from 1 second to 60 seconds, but it didn't work. I added another mcp to test (git) and it was:

Running the inspector as requested:

[DennisTraub]

@luanpaschoal thanks for the update. It looks like it works in Inspector, which is a good sign.

Can you share your ~/.cursor/mcp.json so we can see the exact configuration?

[luanpaschoal]

Hi Dennis!
It's working in Cursor, only in PyCharm it's not, both have this configuration:

{
  "mcpServers": {
    "strands": {
      "command": "uvx",
      "args": [
        "strands-agents-mcp-server"
      ]
    }
  }
}

[DimitrijeGlibic]

After instaling uv as specified in instructions and running npx @modelcontextprotocol/inspector uvx strands-agents-mcp-server it just didn't work.

I fixed it by restarting my computer, don't know why but after that it worked perfectly.

I am using macOS, VS Code and Roo Code. hope it helps