Weather python server fails to load

[sterankin]

Running the weather server seems to hang:

uv run weather.py --verbose
Built weather @ file:///Users/me/src/quickstart-resources/weather-server-python
Uninstalled 2 packages in 16ms
Installed 2 packages in 5ms

Should there be further logs here - anything I can try?

To Reproduce
Simply followed the instruction and pulled down the repo, installed uv etc and tried to run it.

Running the client then fails as I assume the server is not running?

I run the weather mcp python client like this:

uv run client.py '/Users/me/src/quickstart-resources/weather-server-python/weather.py'

and get:


    from mcp.server.fastmcp import FastMCP
ModuleNotFoundError: No module named 'mcp.server.fastmcp'

[masaishi]

I had the exact same issue on macOS! Here's how I fixed it:

When I checked my logs, I found this error:

Error: spawn uv ENOENT

This indicates that the system can't find the uv executable in your PATH, even though you've installed it.

First, try one of these fixes:

1. Create a symlink to uv in a standard location:

   sudo ln -s $(which uv) /usr/local/bin/uv
   

2. Or modify the claude_desktop_config.json file to use the absolute path to your uv installation.

In my case, I still encountered errors after this:

[error] Unexpected token 'm', "mcp run" is not valid JSON

The solution was to use mcp install weather.py with the mcp[cli] extra dependency, which updated my configuration to:

"weather": { 
  "command": "uv", 
  "args": [ 
    "run", 
    "--with", 
    "mcp[cli]", 
    "mcp", 
    "run", 
    "/ABSOLUTE/PATH/TO/weather-server-python/weather.py" 
  ] 
}

This finally got both the server and client working properly. Hope this helps!

[ejstembler]

I had this problem on macOS 15.3.2 (24D81) as well. I solved it by adding "python" to the args:

{
    "mcpServers": {
        "weather": {
            "command": "uv",
            "args": [
                "--directory",
                "/ABSOLUTE/PATH/TO/PARENT/FOLDER/weather",
                "run",
                "python",
                "weather.py"
            ]
        }
    }
}

[thejoeosborne]

@masaishi thank you for this 😩 I just needed to create the symlink and it worked

[vinayakchuni]

I am using instead the following configuration and i had installed the mcp using pip and i am getting the exact same error. Any ideas how could I fix it ?
{
"mcpServers": {
"get_city_temperature": {
"command": "python3",
"args": [
"/Users/vinayakchuni/get-current-temperature-server/server.py"
],
"host": "127.0.0.1",
"port": 5000,
"timeout": 30000
}
}
}

[sivajayaraman]

@ejstembler Thanks for that. It helped me.