axum-impl-file-upload

Overview

Axum receives file uploads through axum::extract::Multipart, the extractor for multipart/form-data request bodies. It is feature-gated behind the multipart Cargo feature and does not exist without it.

Two facts govern every upload handler:

1. Multipart consumes the request body, so it is a FromRequest extractor and MUST be the last argument of the handler. Only one body-consuming extractor is allowed per handler.
2. Axum caps request bodies at 2 MB by default through DefaultBodyLimit. An upload endpoint therefore works for small test files and then rejects real files with a 413-class response until that ceiling is raised.