multipart/form-data packages uploaded form fields or files into separate parts of an HTTP POST request. A FastAPI endpoint needs python-multipart to parse this encoding. section 5.6
A practical upload flow accepts an UploadFile, reads its contents, and returns success before longer ACH parsing and validation work begins.
Uploading an ACH file
A client posts data/sample.ach to /api/v1/files as files={"file": test_file}; the endpoint receives UploadFile and returns HTTP 201 after recording the file.
