How to use uvx to run Python MCP servers

uv is a fast Python package installer and runner developed by Astral (the team behind Ruff). Install it using the official install script. On macOS and Linux, use the curl command below. On Windows, use the PowerShell command. After installation, restart your terminal so the uvx command is available on your PATH.

1# macOS / Linux
2curl -LsSf https://astral.sh/uv/install.sh | sh
3
4# Windows (PowerShell)
5powershell -ExecutionPolicy ByPass -c "irm https://astral.sh/uv/install.ps1 | iex"
6
7# Verify installation
8uvx --version

uvx runs a Python package as a command-line tool in an isolated environment. It downloads the package, installs its dependencies in a temporary virtual environment, and executes it — all in one step. Test this in your terminal first before adding it to your MCP host config. The command syntax is uvx <package-name> followed by any arguments the server needs.

1# Run the git MCP server
2uvx mcp-server-git --repository /path/to/your/repo
3
4# Run the fetch MCP server
5uvx mcp-server-fetch
6
7# Run a specific version
8uvx mcp-server-git@0.6.0 --repository /path/to/your/repo

Add the uvx-based server to your MCP host configuration. Use uvx as the command and put the package name and any arguments in the args array. Add environment variables in the env block just like you would for npx-based servers. The configuration is identical in structure to npx servers — only the command changes.

1// claude_desktop_config.json
2{
3  "mcpServers": {
4    "git": {
5      "command": "uvx",
6      "args": ["mcp-server-git", "--repository", "/Users/yourname/projects/my-repo"]
7    },
8    "fetch": {
9      "command": "uvx",
10      "args": ["mcp-server-fetch"]
11    }
12  }
13}

Just like npx, GUI applications may not find uvx because they do not inherit your shell's PATH. Use the absolute path to uvx in your configuration. Run which uvx in your terminal to find it. On macOS with the official installer, it is typically at ~/.cargo/bin/uvx or ~/.local/bin/uvx. On Homebrew installations, it is /opt/homebrew/bin/uvx.

1# Find absolute path
2which uvx
3# Example: /Users/yourname/.local/bin/uvx
4
5# Use absolute path in config
6{
7  "mcpServers": {
8    "git": {
9      "command": "/Users/yourname/.local/bin/uvx",
10      "args": ["mcp-server-git", "--repository", "/path/to/repo"]
11    }
12  }
13}

Many Python MCP servers need API keys or configuration values passed as environment variables. Add them in the env block of your server config, just like npx-based servers. Python servers access these via os.environ. A common pattern is PYTHONUNBUFFERED=1 which forces Python to flush output immediately — important for stdio transport where buffered output can cause communication delays. If you need help configuring complex Python MCP server deployments, the RapidDev engineering team can assist.

1{
2  "mcpServers": {
3    "custom-python-server": {
4      "command": "uvx",
5      "args": ["my-mcp-server"],
6      "env": {
7        "API_KEY": "your-api-key-here",
8        "PYTHONUNBUFFERED": "1"
9      }
10    }
11  }
12}