aiohttp-apispec 1.1.0

Build and document REST APIs with aiohttp and apispec

aiohttp-apispec

Build and document REST APIs with aiohttp and apispec

aiohttp-apispec key features:

• docs, request_schema and response_schema decorators to add swagger spec support out of the box. If you have < 1.0.0 version you should use use_kwags and marshal_with decorators instead of request_schema and response_schema respectively.
• validation_middleware middleware to enable validating with marshmallow schemas from those decorators

aiohttp-apispec api is fully inspired by flask-apispec library

Contents

• Install
• Quickstart
• Adding validation middleware
• Build swagger web client

Install

pip install aiohttp-apispec

Quickstart

from aiohttp_apispec import (
    docs,
    request_schema,
    response_schema,
    setup_aiohttp_apispec,
)
from aiohttp import web
from marshmallow import Schema, fields


class RequestSchema(Schema):
    id = fields.Int()
    name = fields.Str(description="name")


class ResponseSchema(Schema):
    msg = fields.Str()
    data = fields.Dict()


@docs(
    tags=["mytag"],
    summary="Test method summary",
    description="Test method description",
)
@request_schema(RequestSchema(strict=True))
@response_schema(ResponseSchema(), 200)
async def index(request):
    return web.json_response({"msg": "done", "data": {}})


app = web.Application()
app.router.add_post("/v1/test", index)

# init docs with all parameters, usual for ApiSpec
setup_aiohttp_apispec(app=app, title="My Documentation", version="v1")

# now we can find it on 'http://localhost:8080/api/docs/api-docs'
web.run_app(app)

Class based views are also supported:

class TheView(web.View):
    @docs(
        tags=["mytag"],
        summary="View method summary",
        description="View method description",
    )
    @request_schema(RequestSchema(strict=True))
    @response_schema(ResponseSchema(), 200)
    def delete(self):
        return web.json_response(
            {"msg": "done", "data": {"name": self.request["data"]["name"]}}
        )


app.router.add_view("/v1/view", TheView)

As alternative you can add responses info to docs decorator, which is more compact way. And it allows you not to use schemas for responses documentation:

@docs(
    tags=["mytag"],
    summary="Test method summary",
    description="Test method description",
    responses={
        200: {
            "schema": ResponseSchema(),
            "description": "Success response",
        },  # regular response
        404: {"description": "Not found"},  # responses without schema
        422: {"description": "Validation error"},
    },
)
@request_schema(RequestSchema(strict=True))
async def index(request):
    return web.json_response({"msg": "done", "data": {}})

Adding validation middleware

from aiohttp_apispec import validation_middleware

...

app.middlewares.append(validation_middleware)

Now you can access all validated data in route from request['data'] like so:

@docs(
    tags=["mytag"],
    summary="Test method summary",
    description="Test method description",
)
@request_schema(RequestSchema(strict=True))
@response_schema(ResponseSchema(), 200)
async def index(request):
    uid = request["data"]["id"]
    name = request["data"]["name"]
    return web.json_response(
        {"msg": "done", "data": {"info": f"name - {name}, id - {uid}"}}
    )

You can change Request's 'data' param to another with request_data_name argument of setup_aiohttp_apispec function:

setup_aiohttp_apispec(
    app=app,
    request_data_name="validated_data",
    title="My Documentation",
    version="v1",
    url="/api/docs/api-docs",
)

...


@request_schema(RequestSchema(strict=True))
async def index(request):
    uid = request["validated_data"]["id"]
    ...

If you want to catch validation errors you should write your own middleware and catch web.HTTPClientError, json.JSONDecodeError and so on. Like this:

@web.middleware
async def my_middleware(request, handler):
    try:
        return await handler(request)
    except web.HTTPClientError:
        return web.json_response(status=400)


app.middlewares.extend(
    [
        my_middleware,  # Catch exception by your own, format it and respond to client
        validation_middleware,
    ]
)

Build swagger web client

aiohttp-apispec adds swagger_dict parameter to aiohttp web application after initialization (with setup_aiohttp_apispec function). So you can use it easily with aiohttp_swagger library:

from aiohttp_apispec import setup_aiohttp_apispec
from aiohttp_swagger import setup_swagger


def create_app(app):
    setup_aiohttp_apispec(app)

    async def swagger(app):
        setup_swagger(
            app=app, swagger_url="/api/doc", swagger_info=app["swagger_dict"]
        )

    app.on_startup.append(swagger)
    # now we can access swagger client on '/api/doc' url
    ...
    return app