flaskdocs is a lightweight wrapper around a flask app which aims to centralize both validation and documentation of an API. Declare the schemas you're accept/return, and flaskdocs will let you generate an openapi.json file, as well as validating incoming requests and returning errors to the client if a request doesn't match the given schema.

Example usage:

Declare a flask app and pass it to a flaskdocs API as follows:

from flask import Flask, jsonify

from flaskdocs import API
from flaskdocs.schema import (
    JsonSchema,
    QueryParameterSchema,
    Literal,
    Use,
)

app = Flask(__name__)

api = API(
    title="example",
    version="0.0.1",
    description="Here's an example API",
    app=app,
)

@api.route(
    name="Add Numbers",
    path="/add",
    methods=["GET"],
    description="Add two numbers together and return the sum",
    query_parameter_schema=QueryParameterSchema({
        # use "Use" here to tell the parser try calling float, rather
        # than doing a type check, because queryParameters always come
        # in as strings
        Literal("x", description="The first number to add"): Use(float),
        Literal("y", description="The second number to add"): Use(float),
    }),
    response_schema={200: JsonSchema({
        Literal("sum", description="The sum x + y"): float
    })},
)
def add(x: float, y: float):
    return jsonify({"sum": x + y})

api.output_openapi("example/openapi-spec.json")

To run a more complete example (found in the example folder) run FLASK_APP=example/server.py python -m flask run from this directory.