|AbL|
=====

*Open-source real-time framework for Web, Mobile & Internet of Things.*

Latest release: v\ |version| (:ref:`Changelog`)

.. ifconfig:: not no_network

   .. raw:: html

      <p>
         <a href="https://travis-ci.org/tavendo/AutobahnPython">
            <img src="https://api.travis-ci.org/tavendo/AutobahnPython.png?branch=master" alt="Build Status" />
         </a>
         <a href="http://pypi.python.org/pypi/autobahn">
            <img src="https://pypip.in/download/autobahn/badge.png" alt="Downloads" />
         </a>
      </p>

-----

|AbL| is part of the `Autobahn`_ project and provides open-source implementations of

* `The WebSocket Protocol <http://tools.ietf.org/html/rfc6455>`_
* `The Web Application Messaging Protocol (WAMP) <http://wamp.ws/>`_

in Python 2 and 3, running on `Twisted`_ and `asyncio`_.

WebSocket allows `bidirectional real-time messaging <http://tavendo.com/blog/post/websocket-why-what-can-i-use-it/>`_ on the Web while `WAMP <http://wamp.ws/>`_ provides applications with `high-level communication abstractions <http://wamp.ws/why/>`_ in an open standard WebSocket based protocol.

|AbL| features

* framework for `WebSocket`_ / `WAMP`_ clients
* compatible with Python 2.6, 2.7, 3.3 and 3.4
* runs on `CPython`_, `PyPy`_ and `Jython`_
* runs under `Twisted`_ and `asyncio`_
* implements WebSocket `RFC6455`_ (and older versions like Hybi-10+ and Hixie-76)
* implements `WebSocket compression <http://tools.ietf.org/html/draft-ietf-hybi-permessage-compression>`_
* implements `WAMP`_, the Web Application Messaging Protocol
* supports TLS (secure WebSocket) and proxies
* Open-source (`MIT license <https://github.com/tavendo/AutobahnPython/blob/master/LICENSE>`_)

and much more.

Further, |AbL| is written with these goals

1. high-performance, fully asynchronous and scalable code
2. best-in-class standards conformance and security

We do take those design and implementation goals quite serious. For example, |AbL| has 100% strict passes with `AutobahnTestsuite`_, the quasi industry standard of WebSocket protocol test suites we originally created only to test |AbL|;)

.. note::
   In the following, we will just refer to |Ab| instead of the
   more precise term |AbL| and there is no
   ambiguity.


What can I do with this stuff?
------------------------------

WebSocket is great for apps like **chat**, **trading**, **multi-player games** or **real-time charts**. It allows you to **actively push information** to clients as it happens.

Further, WebSocket allows you to real-time enable your Web user interfaces: **always current information** without reloads or polling. UIs no longer need to be a boring, static thing. Looking for the right communication technology for your next-generation Web apps? Enter WebSocket.

And WebSocket works great not only on the Web, but also as a protocol for wiring up the **Internet-of-Things (IoT)**. Connecting a sensor or actor to other application components in real-time over an efficient protocol. Plus: you are using the *same* protocol to connect frontends like Web browsers.

While WebSocket already is quite awesome, it is still low-level. Which is why we have WAMP. WAMP allows you to **compose your application from loosely coupled components** that talk in real-time with each other - using nice high-level communication patterns ("Remote Procedure Calls" and "Publish & Subscribe").

WAMP enables application architectures with application code **distributed freely across processes and devices** according to functional aspects. Since WAMP implementations exist for **multiple languages**, WAMP applications can be **polyglot**. Application components can be implemented in a language and run on a device which best fit the particular use case.

WAMP is a routed protocol, so you need a WAMP router. We suggest using `Crossbar.io <http://crossbar.io>`_, but there are also `other implementations <http://wamp.ws/implementations/>`_ available.

More:

* `WebSocket - Why, what, and - can I use it? <http://tavendo.com/blog/post/websocket-why-what-can-i-use-it/>`_
* `Why WAMP? <http://wamp.ws/why/>`_


Show me some code!
------------------

A sample **WebSocket server**:

.. code-block:: python

   class MyServerProtocol(WebSocketServerProtocol):

      def onConnect(self, request):
         print("Client connecting: {}".format(request.peer))

      def onOpen(self):
         print("WebSocket connection open.")

      def onMessage(self, payload, isBinary):
         if isBinary:
            print("Binary message received: {} bytes".format(len(payload)))
         else:
            print("Text message received: {}".format(payload.decode('utf8')))

         ## echo back message verbatim
         self.sendMessage(payload, isBinary)

      def onClose(self, wasClean, code, reason):
         print("WebSocket connection closed: {}".format(reason))

Complete example code:

* `WebSocket Echo (Twisted-based) <https://github.com/tavendo/AutobahnPython/tree/master/examples/twisted/websocket/echo>`_
* `WebSocket Echo (Asyncio-based) <https://github.com/tavendo/AutobahnPython/tree/master/examples/asyncio/websocket/echo>`_

Introduction to WebSocket Programming with |ab|:

* :doc:`websocket/programming`

---------

A sample **WAMP application component** implementing all client roles:

.. code-block:: python

   class MyComponent(ApplicationSession):

      @inlineCallbacks
      def onJoin(self, details):

         # 1) subscribe to a topic
         def onevent(msg):
            print("Got event: {}".format(msg))

         yield self.subscribe(onevent, 'com.myapp.hello')

         # 2) publish an event
         self.publish('com.myapp.hello', 'Hello, world!')

         # 3) register a procedure for remoting
         def add2(x, y):
            return x + y

         self.register(add2, 'com.myapp.add2');

         # 4) call a remote procedure
         res = yield self.call('com.myapp.add2', 2, 3)
         print("Got result: {}".format(res))


Complete example code:

* `Twisted <https://github.com/tavendo/AutobahnPython/blob/master/examples/twisted/wamp/beginner/client.py>`__ - * `asyncio <https://github.com/tavendo/AutobahnPython/blob/master/examples/asyncio/wamp/beginner/client.py>`__

Introduction to WAMP Programming with |ab|:

* :doc:`wamp/programming`

----------


Where to start
--------------

To get started, jump to :doc:`installation`.

For developers new to asynchronous programming, Twisted or asyncio, we've collected some useful pointers and information in :doc:`asynchronous-programming`.

For **WebSocket developers**, :doc:`websocket/programming` explains all you need to know about using |ab| as a WebSocket library, and includes a full reference for the relevant parts of the API.

:doc:`websocket/examples` lists WebSocket code examples covering a broader range of uses cases and advanced WebSocket features.

For **WAMP developers**, :doc:`wamp/programming` gives an introduction for programming with WAMP in Python using |ab|.

:doc:`wamp/examples` lists WAMP code examples covering all features of WAMP.


Community
---------

Development of |ab| takes place on the GitHub `source repository <https://github.com/tavendo/AutobahnPython>`_.

.. note::
   We are open for contributions, whether that's code or documentation! Preferably via pull requests.

We also take **bug reports** at the `issue tracker <https://github.com/tavendo/AutobahnPython/issues>`_.

The best place to **ask questions** is on the `mailing list <https://groups.google.com/forum/#!forum/autobahnws>`_. We'd also love to hear about your project and what you are using |ab| for!

Another option is `StackOverflow <http://stackoverflow.com>`_ where `questions <http://stackoverflow.com/questions/tagged/autobahn?sort=newest>`__ related to |ab| are tagged `"autobahn" <http://stackoverflow.com/tags/autobahn/info>`__ (or `"autobahnws" <http://stackoverflow.com/tags/autobahnws/info>`__).

The best way to **Search the Web** for related material is by using these (base) search terms:

* `"autobahnpython" <https://www.google.com/search?q=autobahnpython>`__
* `"autobahnws" <https://www.google.com/search?q=autobahnws>`__

You can also reach users and developers on **IRC** channel ``#autobahn`` at `freenode.net <http://www.freenode.net/>`__.

Finally, we are on `Twitter <https://twitter.com/autobahnws>`_.


.. toctree::
   :hidden:

   installation
   asynchronous-programming
   websocket/programming
   wamp/programming
   websocket/examples
   wamp/examples
   reference/autobahn
   contribute
   changelog
