Response

Use Blueprint.response to specify a Schema class or instance to serialize the response and a status code (defaults to 200).

In the following examples, the GET and PUT methods return an instance of Pet serialized with PetSchema:

@blp.route('/<pet_id>')
class PetsById(MethodView):

    @blp.response(PetSchema)
    def get(self, pet_id):
        return Pet.get_by_id(pet_id)

    @blp.arguments(PetSchema)
    @blp.response(PetSchema)
    def put(self, update_data, pet_id):
        pet = Pet.get_by_id(pet_id)
        pet.update(update_data)
        return pet

Here, the DELETE returns an empty response so no schema is specified.

@blp.route('/<pet_id>')
class PetsById(MethodView):

    @blp.response(code=204)
    def delete(self, pet_id):
        Pet.delete(pet_id)

If a view function returns a list of objects, the Schema must be instanciated with many=True.

@blp.route('/')
class Pets(MethodView):

    @blp.response(PetSchema(many=True))
    def get(self, args):
        return Pet.get()

Note

Even if a view function returns an empty response with a default 200 code, decorating it with Blueprint.response is useful anyway, to return a proper Flask Response object.