Detecting File Mime Types in FastAPI Using the Python Magic Library

fastapi-magic.py

"""
Using `magic` library to detect the MIME type of uploaded files.
"""

from typing import Annotated
from fastapi import FastAPI, File, UploadFile, APIRouter

import magic

app = FastAPI()
#router = APIRouter()


@app.post("/files/", tags=["contrib"])
#@router.post("/files/", tags=["contrib"])
async def create_file(file: Annotated[bytes, File()]):
    return {"file_size": len(file)}


@app.post("/uploadfile/", tags=["contrib"])
#@router.post("/uploadfile/", tags=["contrib"])
async def create_upload_file(file: UploadFile):
    buffer = file.file.read(1024)
    mime_type = magic.from_buffer(buffer, True)
    file.file.seek(0)
    return {"filename": file.filename, "mime": mime_type}