mcp route adds POST request method

[LTaooo]

Describe your changes

mcp route adds POST request method

Issue ticket number and link (if applicable)

#154

[prd-tuong-nguyen]

Waiting for this

[LTaooo]

Waiting for this

If you're in a hurry, you can overwrite the FastApiMCP class first.

Or use this: https://github.com/jlowin/fastmcp

[prd-tuong-nguyen]

@LTaooo Thank you, I just switched to fastmcp

[waltzforvenus]

bumping this

[mustela]

Any plan to merge this soon? Thanks!

[LePtiDev]

I need it also :/

[DoiiarX]

We need it!

[DoiiarX]

For those who don't want to modify the code in their own repository, I recommend using the following monkey patching method.

# demo.py
# author: Doiiars
# ... Other import statements ...
from fastapi_mcp import FastApiMCP
from fastapi_mcp.server import FastApiSseTransport
from fastapi import FastAPI, APIRouter, Request, params, Depends
from typing import Optional, Sequence

# ...

# --- Monkey Patching FastApiMCP ---

# 1. Define our own version, completely replacing the original implementation
def patched_register_mcp_connection_endpoint_sse(
    self,
    router: FastAPI | APIRouter,
    transport: FastApiSseTransport,
    mount_path: str,
    dependencies: Optional[Sequence[params.Depends]],
):
    """
    This is a patched version of _register_mcp_connection_endpoint_sse.
    It replaces @router.get with @router.api_route(methods=["GET", "POST"])
    and injects a custom dependency.
    """
    logger.info(f"--- Patched function called! Registering route for MCP endpoint at '{mount_path}' (GET/POST) ---")

    # --- Add your custom logic here ---
    # For example, we can add a custom dependency for authentication or logging
    async def custom_dependency(request: Request):
        logger.info(f"MCP connection request from: {request.client.host}")
        # You can add authentication logic here, and raise HTTPException if it fails

    # Add our dependency to the existing list of dependencies
    new_dependencies = list(dependencies) if dependencies else []
    new_dependencies.append(Depends(custom_dependency))
  
    logger.info("Custom dependency injected successfully.")
    # ------------------------------------

    # 2. Rewrite the route registration logic, using api_route and specifying methods
    @router.api_route(
        mount_path, 
        include_in_schema=False, 
        operation_id="mcp_connection", 
        dependencies=new_dependencies,  # Use our modified dependencies
        methods=["GET", "POST"]
    )
    async def handle_mcp_connection(request: Request):
        async with transport.connect_sse(request.scope, request.receive, request._send) as (reader, writer):
            await self.server.run(
                reader,
                writer,
                self.server.create_initialization_options(notification_options=None, experimental_capabilities={}),
                raise_exceptions=False,
            )
  
    logger.info(f"Successfully registered MCP endpoint to '{mount_path}' using methods GET, POST.")


# 3. Apply the patch: replace the original version with our patched version
FastApiMCP._register_mcp_connection_endpoint_sse = patched_register_mcp_connection_endpoint_sse
logger.info("FastApiMCP._register_mcp_connection_endpoint_sse has been successfully patched.")

# --- End of Monkey Patching ---


mcp = FastApiMCP(app)

# Mount the MCP server directly to your FastAPI app
mcp.mount()