# FastMCP Configuration Demo This example demonstrates the recommended way to configure FastMCP servers using `fastmcp.json`. ## Migration from Dependencies Parameter Previously (deprecated as of FastMCP 2.11.4), you would specify dependencies in the Python code: ```python mcp = FastMCP("Demo Server", dependencies=["pyautogui", "Pillow"]) ``` Now, dependencies are declared in `fastmcp.json`: ```json { "environment": { "dependencies": ["pyautogui", "Pillow"] } } ``` ## Running the Server With the configuration file in place, you can run the server in several ways: ```bash # Auto-detect fastmcp.json in current directory cd examples/mcp_server_config_demo fastmcp run # Or specify the config file explicitly fastmcp run examples/mcp_server_config_demo/fastmcp.json # Or use development mode with the Inspector UI fastmcp dev examples/mcp_server_config_demo/fastmcp.json ``` ## Benefits - **Single source of truth**: All configuration in one place - **Environment isolation**: Dependencies are installed in an isolated UV environment - **No import-time issues**: Dependencies are installed before the server is imported - **IDE support**: JSON schema provides autocomplete and validation - **Shareable**: Easy to share complete server configuration with others ## Configuration Structure The `fastmcp.json` file supports three main sections: 1. **entrypoint** (required): The Python file containing your server 2. **environment** (optional): Python version and dependencies 3. **deployment** (optional): Runtime settings like transport and logging See the [full documentation](https://gofastmcp.com/docs/deployment/server-configuration) for more details.