Allow Export of Python Code Generated by .from_openapi() for Debugging Purposes

[rcontesti]

Hi,

I'm currently using the .from_openapi method with my OpenApi file, but I'm getting some errors and I wish I could debug them manually. Is there any way I could get an intermediate file with all the endpoints methods generated in a python file?

I'm looking for the equivalent of https://github.com/koxudaxi/fastapi-code-generator, that allows to check what is actually being generated and debug if needed.

Thanks!

[jlowin]

Code is not being generated per se - I'd recommend cloning an editable copy of this repo and setting breakpoints to see the objects created! You can investigate errors directly that way.

[jbnitorum]

I ran into something slightly similar that might be helpful. There no doc on how to get to your tools as python objects when they are created from an openapi spec. I needed to get to a tool created so that I could use a tool the tool transformer. In that same vein I'd assume you could get a tool object and run it like a function and get a traceback.

So in example below you can just call og_tool like a function for debugging. There probably could be a cleaner way to get to the underlying tools when they are created using .from_openapi (maybe I'm missing it?).

from fastmcp import FastMCP
from fastmcp.server.openapi import RouteMap, MCPType
from fastmcp.tools import Tool
import asyncio

API_KEY='1234'

openapi_spec = httpx.get("https://www.example.com/openapi.json").json()

client = httpx.AsyncClient(base_url="https://www.example.com", headers={'x-api-key': API_KEY})

mcp = FastMCP.from_openapi(
    openapi_spec=openapi_spec,
    client=client,
    name="Test Server",
    route_maps=[
        RouteMap(
            methods=["GET"], 
            pattern=".*", 
            mcp_type=MCPType.TOOL,
        )
]
)

og_tool = asyncio.run(mcp.get_tool('the_tool_created_here'))

new_tool = Tool.from_tool(
    og_tool,
    name="The New Tool",
    description="""
        More descriptive than the old
        """,
)

mcp.add_tool(new_tool)

[rcontesti]

Thanks @jbnitorum. I decided to go up, and build a FASTAPI object. There are tools for checking at that level. Tough my issue now is how to fix a broken API spec in a rather automatic way. I'm currently building an Interactive Brokers API WEB MCP, the spec is full of errors and neither claude nor gemini have provided any good solutions.