# Understanding Server Parameters (/tools/mcp/server-params)



The recommended way to configure `MCPTools` is to use the `command` or `url` parameters.

Alternatively, you can use the `server_params` parameter with `MCPTools` to configure the connection to the MCP server in more detail.

When using the **stdio** transport, the `server_params` parameter should be an instance of `StdioServerParameters`. It contains the following keys:

* `command`: The command to run the MCP server.
  * Use `npx` for mcp servers that can be installed via npm.
  * Use `uvx` for mcp servers that can be installed via uvx.
  * Use custom binary executables (e.g., `./my-server`, `../usr/local/bin/my-server`, or binaries in your PATH).
* `args`: The arguments to pass to the MCP server.
* `env`: Optional environment variables to pass to the MCP server. The MCP SDK starts with its safe default environment, including `PATH` and the platform's required home-directory variable, then overlays the entries you provide. This applies to an explicit `StdioServerParameters` instance and to the `command` shortcut.

For example:

```python
{
    "GOOGLE_MAPS_API_KEY": os.getenv("GOOGLE_MAPS_API_KEY"),
}
```

When using the **SSE** transport, the `server_params` parameter should be an instance of `SSEClientParams`. It contains the following fields:

* `url`: The URL of the MCP server.
* `headers`: Headers to pass to the MCP server (optional).
* `timeout`: Timeout for the connection to the MCP server (optional).
* `sse_read_timeout`: Timeout for the SSE connection itself (optional).

When using the **Streamable HTTP** transport, the `server_params` parameter should be an instance of `StreamableHTTPClientParams`. It contains the following fields:

* `url`: The URL of the MCP server.
* `headers`: Headers to pass to the MCP server (optional).
* `timeout`: `Optional[float]` in seconds for HTTP operations. Defaults to 30 seconds.
* `sse_read_timeout`: `Optional[float]` in seconds to wait for a new event before disconnecting. Defaults to 5 minutes.
* `terminate_on_close`: Whether to request termination of the server session when the client closes. This does not keep the local HTTP connection open.

SSE timeouts also use numeric seconds. Legacy `timedelta` values are normalized to seconds for compatibility.