Python Multipart

A high-performance streaming multipart parser for Python that powers form and file handling in FastAPI and Starlette.

Python Multipart is the industry standard for parsing multipart/form-data and application/x-www-form-urlencoded payloads. It functions as the primary engine for FastAPI and Starlette (the frameworks defining modern Python web development). The library uses a state-machine architecture to process incoming streams in small chunks: this prevents memory spikes during gigabyte-scale file uploads. It handles complex nested parts and custom headers with zero-copy efficiency. This tool is essential for any developer building robust, asynchronous web services that require reliable data ingestion.

https://github.com/Kludex/python-multipart