Unable to download though @app.post using StreamingResponse

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 = FastAPI()

origins = ["*"]

app.add_middleware(
    CORSMiddleware,
    allow_origins=origins,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

@app.post("/download_test")
async def admin_download_domain_file(request: Request):
    import xlsxwriter
    from fastapi.responses import StreamingResponse, FileResponse
    from io import BytesIO

    output = BytesIO()
    workbook = xlsxwriter.Workbook(output)
    worksheet = workbook.add_worksheet()
    worksheet.write(0, 0, "test")
    workbook.close()
    headers = {"Content-Disposition": "filename=filename.xlsx"}
    return StreamingResponse(output, headers=headers)

Description

I can’t download file though @app.post, but if i change it to @app.get, it works fine. The reason I need to use @app.post is because I need to send a list to server, maybe hundreds of url in it then return a xlsx file which contains their imformation. I got these –Failed to fetch. –Possible Reasons: –CORS –Network Failure –URL scheme must be “http” or “https” for CORS request. in http://127.0.0.1:8000/docs And everytime I use POST method it will jump to GET method like this: INFO: 127.0.0.1:44548 - “POST /download_test HTTP/1.1” 200 OK INFO: 127.0.0.1:44688 - “GET /download_test HTTP/1.1” 405 Method Not Allowed But I didn’t define GET method. I have set allow_origins=[‘*’], it does’t work.

Operating System

Linux

Operating System Details

No response

FastAPI Version

0.66.1

Python Version

3.9.5

Additional Context

No response

[skk294]

@Dustyposa Thanks for your help. According to your words, I finally realize it’s the XDM Browser Monitor’s problem, it somehow make me jump to GET method. After shutting it down, everything works fine.

[jramirez92]

I’m having the same issue, Is there any way to update the Swagger version in FastApi?