Return a custom JSON-like object when rate limit is hit

[nocturn9x]

I know it is possible to specify the error message in the limit decorator, but I'm building a very complex API and all of my requests need to be consistent and follow a specific schema that I represented using a pydantic.BaseModel subclass (basically a dataclass on steroids). Is it possible to return such a custom object instead of the default starlette.responses.JSONResponse?

My response looks like this (once converted to a dictionary)

{"request_id" : "foobarbaz", "status_code": 416, "response_data": None, "error_message" : "Unsupported media type"}

[laurentS]

@nocturn9x I just realised that I've left this issue abandoned for months, sorry. Did you ever figure out a solution to your problem? Is it still relevant? As a first thought, I imagine you could subclass Limiter and overload the _inject_headers method to do what you need. I'm not sure there's much value in doing this in slowapi, as I suspect it's a fairly uncommon use case, but I might be wrong :)

[nocturn9x]

Hi. Yeah this issue would still be relevant, can you illustrate any way of customizing that method?

[laurentS]

Have you tried something like this? (adapting the FastAPI example from the docs)

    from fastapi import FastAPI
    from slowapi import Limiter, _rate_limit_exceeded_handler
    from slowapi.util import get_remote_address
    from slowapi.errors import RateLimitExceeded

    class LimiterWithCustomResponse(Limiter):
        def _inject_headers(...) -> YourResponseModel:
            # your custom code here that overloads the existing method
            pass

    limiter = LimiterWithCustomResponse(key_func=get_remote_address)
    app = FastAPI()
    app.state.limiter = limiter
    app.add_exception_handler(RateLimitExceeded, _rate_limit_exceeded_handler)

    @app.get("/home")
    @limiter.limit("5/minute")
    async def homepage(request: Request):
        return PlainTextResponse("test")

    @app.get("/mars")
    @limiter.limit("5/minute")
    async def homepage(request: Request, response: YourResponseModel):
        return {"key": "value"}

Let me know if this helps.

[laurentS]

@nocturn9x Can we close this issue?

[nocturn9x]

@nocturn9x Can we close this issue?

Yup, sorry if I never replied back. Thanks for the solution, btw!