fastmcp.client.transports.inference

Functions

infer_transport ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/client/transports/inference.py#L61" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

infer_transport(transport: ClientTransport | FastMCP | FastMCP1Server | AnyUrl | Path | MCPConfig | dict[str, Any] | str) -> ClientTransport

Infer the appropriate transport type from the given transport argument.

This function attempts to infer the correct transport type from the provided argument, handling various input types and converting them to the appropriate ClientTransport subclass.

The function supports these input types:

• ClientTransport: Used directly without modification
• FastMCP or FastMCP1Server: Creates an in-memory FastMCPTransport
• Path or str (file path): Creates PythonStdioTransport (.py) or NodeStdioTransport (.js)
• AnyUrl or str (URL): Creates StreamableHttpTransport (default) or SSETransport (for /sse endpoints)
• MCPConfig or dict: Creates MCPConfigTransport, potentially connecting to multiple servers

For HTTP URLs, they are assumed to be Streamable HTTP URLs unless they end in /sse.

For MCPConfig with multiple servers, a composite client is created where each server is mounted with its name as prefix. This allows accessing tools and resources from multiple servers through a single unified client interface, using naming patterns like servername_toolname for tools and protocol://servername/path for resources. If the MCPConfig contains only one server, a direct connection is established without prefixing.

Examples:

# Connect to a local Python script
transport = infer_transport("my_script.py")

# Connect to a remote server via HTTP
transport = infer_transport("http://example.com/mcp")

# Connect to multiple servers using MCPConfig
config = {
    "mcpServers": {
        "weather": {"url": "http://weather.example.com/mcp"},
        "calendar": {"url": "http://calendar.example.com/mcp"}
    }
}
transport = infer_transport(config)