FastAPI.">Starlette has a head request that works right along side your get requests.
This morning I fiddled around with custom routes for GET and HEAD, but had
to manually set some things about the file, and was still missing e-tag in
the end. Turns out as a developer you can just add a head route to
your get routes and starlette will strip the content for you, while
preserving all of those good headers that fastapi FileResponse created
automatically for you.
from fastapi import APIRouter
from fastapi.response import FileResponse
from fastapi import Request
from pathlib import Path
router = APIRouter()
@router.get("/file/{filename}")
@router.head("/file/{filename}")
async def get_file(filename: str, request: Request,):
headers = {
"Cache-Control": "no-cache, no-store, must-revalidate",
}
from pathlib import Path
filename = Path(f"data/{filename}")
if not filename.exists():
raise HTTPException(status_code=404, detail="File not found")
return FileResponse(filename, headers=headers)
Here is an example of the response with curl.
❯ curl -I -L "http://localhost:8100/api/file/e5523925-1565-454c-bab3-c70c4deabc83.webp?width=250"
HTTP/1.1 200 OK
date: Wed, 22 Oct 2025 14:16:03 GMT
server: uvicorn
cache-control: no-cache, no-store, must-revalidate
content-type: image/webp
content-length: 17206
last-modified: Tue, 23 Sep 2025 14:03:20 GMT
etag: f891660c1543feb1af7564f08abdd511
❯ curl -I -L "http://localhost:8100/api/file/unknown-file.webp?width=250"
HTTP/1.1 404 Not Found
date: Wed, 22 Oct 2025 14:16:11 GMT
server: uvicorn
content-length: 27
content-type: application/json
