fastmcp dev Error

[johnson7788]

When I run the desktop.py with dev mode, like this, Query parameters always run with other args, it runs my t8.py script, very strange? is there any cache?

fastmcp dev desktop.py

Starting MCP inspector... ⚙️ Proxy server listening on port 6277

🔍 MCP Inspector is up and running at http://127.0.0.1:6274 🚀 New SSE connection Query parameters: { transportType: 'stdio', command: 'uv', args: 'run --with fastmcp fastmcp run t8.py', env: '{"HOME":"/Users/admin","LOGNAME":"admin","PATH":"

/Users/admin/miniforge3/envs/pipecat/bin/fastmcp pip freeze | grep fastmcp -e git+https://github.com/jlowin/fastmcp@91fba14c88a9f21698b815615d4e6a2e28fe72ee#egg=fastmcp

I think the error come from @modelcontextprotocol/inspector. i try npx run it ,always error npx @modelcontextprotocol/inspector

[vivian1311]

Hi, I think I'm encountering a related issue when trying to run fastmcp dev.

Here's my setup: OS: macOS Python environment: virtualenv with fastmcp installed

When I run:

fastmcp dev readme-quickstart.py

I get this error:

sh:  mcp-inspector: command not found
[ERROR] Dev server failed

I tried running:

npx @modelcontextprotocol/inspector

But it fails with similar errors. I suspect fastmcp dev is expecting the binary to be available as mcp-inspector, but this command isn't globally linked or discoverable in my path.

[aimsecond]

I have the same issue as @vivian1311 encountered on MacOS.

I got it working by running:

npm install -g @modelcontextprotocol/inspector

[jlowin]

FastMCP will attempt to install or upgrade the inspector if it isn't found, but this can fail due to permissions errors or other problems, in which case manually installing should work! If you have an inspector issue, please open it on the inspector repo.