ruipgil/spectree

API spec validator and OpenAPI document generator for Python web frameworks.

Spectree

Yet another library to generate OpenAPI document and validate request & response with Python annotations.

Features

• Less boilerplate code, only annotations, no need for YAML ✨
• Generate API document with Redoc UI or Swagger UI 😋
• Validate query, JSON data, response data with pydantic 😉
• Current support:
  • Flask example
  • Falcon example
  • Starlette example

Quick Start

install with pip: pip install spectree

Examples

Check the examples folder.

Step by Step

1. Define your data structure used in (query, json, headers, cookies, resp) with pydantic.BaseModel
2. create spectree.SpecTree instance with the web framework name you are using, like api = SpecTree('flask')
3. api.validate decorate the route with
   • query
   • json
   • headers
   • cookies
   • resp
   • tags
4. access these data with context(query, json, headers, cookies) (of course, you can access these from the original place where the framework offered)
   • flask: request.context
   • falcon: req.context
   • starlette: request.context
5. register to the web application api.register(app)
6. check the document at URL location /apidoc/redoc or /apidoc/swagger

If the request doesn't pass the validation, it will return a 422 with JSON error message(ctx, loc, msg, type).

How To

How to add summary and description to endpoints?

Just add docs to the endpoint function. The 1st line is the summary, and the rest is the description for this endpoint.

How to add description to parameters?

Check the pydantic document about description in Field.

Any config I can change?

Of course. Check the config document.

You can update the config when init the spectree like:

SpecTree('flask', title='Demo API', version='v1.0', path='doc')

What is Response and how to use it?

To build a response for the endpoint, you need to declare the status code with format HTTP_{code} and corresponding data (optional).

Response('HTPP_200', HTTP_403=ForbidModel)

What should I return when I'm using the library?

No need to change anything. Just return what the framework required.

Demo

Try it with http post :8000/api/user name=alice age=18. (if you are using httpie)

Flask

from flask import Flask, request, jsonify
from pydantic import BaseModel, Field, constr
from spectree import SpecTree, Response


class Profile(BaseModel):
    name: constr(min_length=2, max_length=40) # Constrained Str
    age: int = Field(
        ...,
        gt=0,
        lt=150,
        description='user age(Human)'
    )


class Message(BaseModel):
    text: str


app = Flask(__name__)
api = SpecTree('flask')


@app.route('/api/user', methods=['POST'])
@api.validate(json=Profile, resp=Response('HTTP_404', HTTP_200=Message), tags=['api'])
def user_profile():
    """
    verify user profile (summary of this endpoint)

    user's name, user's age, ... (long description)
    """
    print(request.context.json) # or `request.json`
    return jsonify(text='it works')


if __name__ == "__main__":
    api.register(app) # if you don't register in api init step
    app.run(port=8000)

Falcon

import falcon
from wsgiref import simple_server
from pydantic import BaseModel, Field, constr
from spectree import SpecTree, Response


class Profile(BaseModel):
    name: constr(min_length=2, max_length=40)  # Constrained Str
    age: int = Field(
        ...,
        gt=0,
        lt=150,
        description='user age(Human)'
    )


class Message(BaseModel):
    text: str


api = SpecTree('falcon')


class UserProfile:
    @api.validate(json=Profile, resp=Response('HTTP_404', HTTP_200=Message), tags=['api'])
    def on_post(self, req, resp):
        """
        verify user profile (summary of this endpoint)

        user's name, user's age, ... (long description)
        """
        print(req.context.json)  # or `req.media`
        resp.media = {'text': 'it works'}


if __name__ == "__main__":
    app = falcon.API()
    app.add_route('/api/user', UserProfile())
    api.register(app)

    httpd = simple_server.make_server('localhost', 8000, app)
    httpd.serve_forever()

Starlette

import uvicorn
from starlette.applications import Starlette
from starlette.routing import Route, Mount
from starlette.responses import JSONResponse
from pydantic import BaseModel, Field, constr
from spectree import SpecTree, Response


class Profile(BaseModel):
    name: constr(min_length=2, max_length=40)  # Constrained Str
    age: int = Field(
        ...,
        gt=0,
        lt=150,
        description='user age(Human)'
    )


class Message(BaseModel):
    text: str


api = SpecTree('starlette')


@api.validate(json=Profile, resp=Response('HTTP_404', HTTP_200=Message), tags=['api'])
async def user_profile(request):
    """
    verify user profile (summary of this endpoint)

    user's name, user's age, ... (long description)
    """
    print(request.context.json)  # or await request.json()
    return JSONResponse({'text': 'it works'})


if __name__ == "__main__":
    app = Starlette(routes=[
        Mount('api', routes=[
            Route('/user', user_profile, methods=['POST']),
        ])
    ])
    api.register(app)

    uvicorn.run(app)

FAQ

ValidationError: missing field for headers

The HTTP headers' keys in Flask are capitalized, in Falcon are upper cases, in Starlette are lower cases. You can use pydantic.root_validators(pre=True) to change all the keys into lower cases or upper cases.