Flasgger
Easy OpenAPI specs and Swagger UI for your Flask API
...Flasgger also provides validation of the incoming data, using the same specification it can validate if the data received as a POST, PUT, PATCH is valid against the schema defined using YAML, Python dictionaries or Marshmallow Schemas. Flasgger can work with simple function views or MethodViews using docstring as specification, or using @swag_from decorator to get specification from YAML or dict and also provides SwaggerView which can use Marshmallow Schemas as specification. Flasgger is compatible with Flask-RESTful so you can use Resources and swag specifications together, take a look at the restful example. Flasgger also supports Marshmallow APISpec as base template for specification.