flask-restful

pip install flask-restful

from flask import Flask, request
from flask_restful import Api, Resource

app = Flask(__name__)
api = Api(app)

class PostListResource(Resource):

    def get(self):
        posts = Post.query.all()
        # posts_schema - flask-marshmallow
        return posts_schema.dump(posts)

    def post(self):
        new_post = Post(
            title=request.json['title'],
            content=request.json['content']
        )
        db.session.add(new_post)
        db.session.commit()
        return post_schema.dump(new_post)

class PostResource(Resource):

    def get(self, post_id):
        post = Post.query.get_or_404(post_id)
        return post_schema.dump(post)

    def patch(self, post_id):
        pass

    def delete(self, post_id):
        pass

api.add_resource(PostListResource, '/posts')
api.add_resource(PostResource, '/posts/<int:post_id>')