New Python Package Adds HTTP Security Headers to FastAPI Without Breaking Swagger UI

A developer has released fastapi-security-headers, a lightweight Python package designed to simplify adding HTTP security headers to FastAPI applications. The package addresses a common problem where enforcing a strict Content Security Policy (CSP) breaks FastAPI's built-in interactive documentation, Swagger UI and ReDoc. Built as a pure ASGI middleware with no external dependencies, it processes and encodes headers once at startup to minimize runtime overhead. It ships with a docs-aware preset called swagger_friendly that applies strict security policies while preserving full functionality of the API documentation pages. The package can be installed via pip and configured with a single middleware call added to an existing FastAPI application.