flask-smorest
Marshmallow's official Flask REST integration. Uses marshmallow models for request/response validation and serialization, and generates OpenAPI with Swagger UI.
Python › Projects > Web APIs: “A Flask/Marshmallow-based REST API framework with automatic OpenAPI documentation.”
Flask › Third-Party Extensions > APIs > RESTful API + Swagger/OpenAPI Documentation Support: “Marshmallow's official Flask REST integration. Uses marshmallow models for request/response validation and serialization, and generates OpenAPI with Swagger UI.”