Insomnia freezes after redirecting the request with multipart file in the body

[YFender]

Expected Behavior

A POST request containing a file in its body, formatted as multipart/form-data, is sent to the FastAPI server in a loop exceeding 100 iterations. The server, adhering to its default configuration, issues a redirect with a 307 status code to the same path, albeit without a trailing slash. Following this redirect, the request is expected to be successfully processed and returned.

Actual Behavior

When executed in a loop, after approximately 20–25 iterations, the server issues a redirect with a 307 status code; however, it ceases to receive any further requests from Insomnia. Meanwhile, Insomnia either halts at this iteration, continuously incrementing the execution time as if awaiting a prolonged server response, or displays an error dialog, as depicted in the screenshot provided below.

Reproduction Steps

To reproduce the issue, it is sufficient to create a minimal FastAPI server where a function accepts a file and simply returns a response and send multiple requests to it in a loop.

import uvicorn
from fastapi import FastAPI, UploadFile

app = FastAPI()

@app.post("/uploadfile/")
async def upload_handler(file: UploadFile):
    return {"filename": file.filename}

if __name__ == "__main__":
    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=False)

As I said, file in the requests body must be in Multipart/form-data format.

Is there an existing issue for this?

• I have searched the issue tracker for this problem.

Which sync method do you use?

• Git sync.
• Insomnia Cloud sync.
• Local only

Additional Information

Notably, Insomnia does not freeze when sending a single request or when sending requests in a loop to the correct path that does not trigger a redirect. However, in such cases, the error dialog mentioned earlier appears upon completion of the loop. Additionally, I have confirmed that the server is functioning correctly and the issue does not originate from its side, as identical operations in Postman execute seamlessly without any problems.

Insomnia Version

10.3.1

What operating system are you using?

Windows

Operating System Version

Windows 11 LTSC 2H24

Installation method

downloaded from insomnia.rest

Last Known Working Insomnia version

No response