Detect if client canceled the request

[lsmith77]

First Check

• I added a very descriptive title to this issue.
• I used the GitHub search to find a similar issue and didn't find it.
• I searched the FastAPI documentation, with the integrated search.
• I already searched in Google "How to X in FastAPI" and didn't find any information.
• I already read and followed all the tutorial in the docs and didn't find an answer.
• I already checked if it is not related to FastAPI but to Pydantic.
• I already checked if it is not related to FastAPI but to Swagger UI.
• I already checked if it is not related to FastAPI but to ReDoc.

Commit to Help

• I commit to help with one of those options 👆

Example Code

@app.post("/foo", status_code=201)
def foo(
    request: Request, user_request_in: RequestInEvent, background_tasks: BackgroundTasks
):
    .. do some work ..

    background_tasks.add_task(write_user_training_data, request, user_request_in)

    return ..

Description

I have an API that sends an API request for every key pressed in a client. Since its quite common that another key is pressed before the request returns, the client cancels these requests.

Is there some way I can detect if the request was canceled inside the background task?

Operating System

Linux

Operating System Details

No response

FastAPI Version

0.68.2

Python Version

3.9

Additional Context

No response

[raphaelauv]

fastAPI is not a workload management process. Also your question is already on stackoverflow -> https://stackoverflow.com/questions/68300429/fastapi-background-task-kill

I think you can close this issue @lsmith77 , Thank you

[lsmith77]

It seems my explanation was not clear.

I am not looking for FastAPI to automatically end execution of the background task if the client cancels the request.

I want the background task to run, but inside the background task I want to be able to log if the client actually read the response or not.