API Star ✨🚀✨🌟

A smart Web API framework, designed for Python 3.

Install API Star:

$ pip3 install apistar

Create a new project:

$ apistar new --template minimal
app.py
tests.py
$ cat app.py
from apistar import App, Route

def welcome():
    return {'message': 'Welcome to API Star!'}

app = App(routes=[
    Route('/', 'GET', welcome)
])

Run the application:

$ apistar run
Running at http://localhost:8080/

Run the tests:

$ apistar test
tests.py ..
===== 2 passed in 0.05 seconds =====

Requests

API Star allows you to dynamically inject various information about the incoming request into your views using type annotation.

from apistar import http

def show_request(request: http.Request):
    return {
        'method': request.method,
        'url': request.url,
        'headers': dict(request.headers)
    }

def show_query_params(query_params: http.QueryParams):
    return {
        'params': dict(query_params)
    }

def show_user_agent(user_agent: http.Header):
    return {
        'user-agent': user_agent
    }

Some of the components you might use most often:

Component	Description
`Request`	The HTTP request. Includes `.method`, `.url`, and `.headers` attributes.
`Headers`	The request headers, returned as a dictionary-like object.
`Header`	Lookup a single request header, corresponding to the argument name. Returns a string or `None`.
`QueryParams`	The request query parameters, returned as a dictionary-like object.
`QueryParam`	Lookup a single query parameter, corresponding to the argument name. Returns a string or `None`.

Responses

By default API star expects view to return plain data, and will return 200 OK responses.

def create_project():
    return {'name': 'new project', 'id': 123}

You can instead set the status code or headers by annotating the view as returning a Response.

def create_project() -> Response:
    data = {'name': 'new project', 'id': 123}
    headers = {'Location', 'http://example.com/project/123/'}
    return Response(data, status=201, headers=headers)

URL Routing

Use {curly_braces} in your URL conf to include a URL path parameter.

def echo_username(username):
    return {'message': f'Welcome, {username}!'}

app = App(routes=[
    Route('/{username}/', 'GET', echo_username)
])

Use type annotation on the view method to include typed URL path parameters.

users = {0: 'penny', 1: 'benny', 2: 'jenny'}

def echo_username(user_id: int):
    username = users[user_id]
    return {'message': f'Welcome, {username}!'}

app = App(routes=[
    Route('/{user_id}/', 'GET', echo_username)
])

Parameters which do not correspond to a URL path parameter will be treated as query parameters.

def echo_username(username):
    if username is None:
        return {'message': 'Welcome!'}
    return {'message': f'Welcome, {username}!'}

app = App(routes=[
    Route('/hello/', 'GET', echo_username)
])

WSGI

Because API views are so dynamic, they'll even let you drop right down to returning a WSGI response directly:

from apistar import wsgi

def hello_world() -> wsgi.WSGIResponse:
    wsgi.WSGIResponse(
        '200 OK',
        [('Content-Type', 'text/plain')],
        [b'Hello, world!']
    )

You can also inject the WSGI environment into your view arguments:

def debug_environ(environ: wsgi.WSGIEnviron):
    return {
        'environ': environ
    }

Testing

API Star includes the py.test testing framework. You can run all tests in a tests.py module or a tests/ directory, by using the following command:

$ apistar test

The simplest way to test a view is to call it directly.

from app import hello_world

def test_hello_world():
    assert hello_world() == {"hello": "world"}

There is also a test client, that allows you to make HTTP requests directly to your application, using the requests library.

from apistar.test import TestClient

def test_hello_world():
    client = TestClient()
    response = client.get('/hello_world/')
    assert response.status_code == 200
    assert response.json() == {"hello": "world"}

Requests made using the test client may use either relative URLs, or absolute URLs. In either case, all requests will be directed at your application, rather than making external requests.

response = client.get('http://www.example.com/hello_world/')

Performance

The following results were obtained on a 2013 MacBook Air, using the simplest "JSON Serialization" TechEmpower benchmark.

Framework	Configuration	Requests/sec	Avg Latency
API Star	gunicorn + meinheld	25,195	7.94ms
Sanic	uvloop	21,233	10.19ms
Falcon	gunicorn + meinheld	16,692	12.08ms
Flask	gunicorn + meinheld	5,238	38.28ms

A pull request has been issued to add API Star to future rounds of the TechEmpower benchmarks. In the future we plan to be adding more realistic & useful test types, such as database query performance.

Deployment

A development server is available, using the run command:

$ apistar run

The recommended production deployment is GUnicorn, using the Meinheld worker.

$ pip install gunicorn
$ pip install meinheld
$ gunicorn app:app.wsgi --workers=4 --bind=0.0.0.0:5000 --pid=pid --worker-class=meinheld.gmeinheld.MeinheldWorker

Typically you'll want to run as many workers as you have CPU cores on the server.

API Star is BSD licensed code.
Designed & built in Brighton, England.
— ⭐️ —

yoshimaa / apistar