Responder: a familiar HTTP Service Framework for Python

The Python world certainly doesn't need more web frameworks. But, it does need more creativity, so I thought I'd bring some of my ideas to the table and see what I could come up with.

But will it blend?

import responder

api = responder.API()

@api.route("/{greeting}")
def greet_world(req, resp, *, greeting):
    resp.text = f"{greeting}, world!"

if __name__ == '__main__':
    api.run()

This gets you a WSGI app, with WhiteNoise pre-installed, jinja2 templating (without additional imports), and a production webserver (ready for slowloris attacks), serving up requests with gzip compression automatically.

Class-based views (and setting some headers and stuff):

@api.route("/{greeting}")
class GreetingResource:
    def on_request(req, resp, *, greeting):   # or on_get...
        resp.text = f"{greeting}, world!"
        resp.headers.update({'X-Life': '42'})
        resp.status_code = api.status_codes.HTTP_416

Render a template, with arguments:

@api.route("/{greeting}")
def greet_world(req, resp, *, greeting):
    resp.content = api.template("index.html", greeting=greeting)

The api instance is available as an object during template rendering.

Serve a GraphQL API:

import graphene

class Query(graphene.ObjectType):
    hello = graphene.String(name=graphene.String(default_value="stranger"))

    def resolve_hello(self, info, name):
        return "Hello " + name

api.add_route("/graph", graphene.Schema(query=Query))

We can then send a query to our service:

>>> requests = api.session()
>>> r = requests.get("http://;/graph", params={"query": "{ hello }"})
>>> r.json()
{'data': {'hello': 'Hello stranger'}}

Or, request YAML back:

>>> r = requests.get("http://;/graph", params={"query": "{ hello(name:\"john\") }"}, headers={"Accept": "application/x-yaml"})
>>> print(r.text)
data: {hello: Hello john}

Want HSTS?

api = responder.API(enable_hsts=True)

Boom. ✨🍰✨

The Basic Idea

The primary concept here is to bring the nicities that are brought forth from both Flask and Falcon and unify them into a single framework, along with some new ideas I have. I also wanted to take some of the API primitives that are instilled in the Requests library and put them into a web framework. So, you'll find a lot of parallels here with Requests.

• Setting resp.text sends back unicode, while setting resp.content sends back bytes.
• Setting resp.media sends back JSON/YAML (.text/.content override this).
• Case-insensitive req.headers dict (from Requests directly).
• resp.status_code, req.method, req.url, and other familar friends.

New Ideas

• A built in testing client that uses the actual Requests you know and love.
• The ability to mount other WSGI apps easily.
• Automatic gzipped-responses (still working on that).
• In addition to Falcon's on_get, on_post, etc methods, Responder features an on_request method, which gets called on every type of request, much like Requests.
• WhiteNoise is built-in, for serving static files.
• Waitress built-in as a production web server. I would have chosen Gunicorn, but it doesn't run on Windows. Plus, Waitress serves well to protect against slowloris attacks, making nginx unnecessary in production.
• GraphQL support, via Graphene. The goal here is to have any GraphQL query exposable at any route, magically.

Old Ideas

• Flask-style route expression, with new capabilities -- primarily, the ability to cast a parameter to integers as well as other types that are missing from Flask, all while using Python 3.6+'s new f-string syntax.

• I love Falcon's "every request and response is passed into to each view and mutated" methodology, especially response.media, and have used it here. In addition to supporting JSON, I have decided to support YAML as well, as Kubernetes is slowly taking over the world, and it uses YAML for all the things. Content-negotiation and all that.

Future Ideas

• I want to be able to "mount" any WSGI app into a sub-route.
• Cooke-based sessions are currently an afterthought, as this is an API framework, but websites are APIs too.
• Potentially support ASGI instead of WSGI. Will the tradeoffs be worth it? This is a question to ask. Procedural code works well for 90% use cases.
• If frontend websites are supported, provide an official way to run webpack.

The Goal

The primary goal here is to learn, not to get adoption. Though, who knows how these things will pan out.

When can I use it?

When it's ready. It's not. I started work on this a few days ago. It works surprisingly well, considering! :)