.. _extensions:

Flask Extensions
================

Flask extensions extend the functionality of Flask in various different
ways.  For instance they add support for databases and other common tasks.

Finding Extensions
------------------

Flask extensions are listed on the `Flask Extension Registry`_ and can be
downloaded with :command:`easy_install` or :command:`pip`.  If you add a Flask extension
as dependency to your :file:`requirements.txt` or :file:`setup.py` file they are
usually installed with a simple command or when your application installs.

Using Extensions
----------------

Extensions typically have documentation that goes along that shows how to
use it.  There are no general rules in how extensions are supposed to
behave but they are imported from common locations.  If you have an
extension called ``Flask-Foo`` or ``Foo-Flask`` it should be always
importable from ``flask_foo``::

    import flask_foo

Building Extensions
-------------------

While `Flask Extension Registry`_ contains many Flask extensions, you may not find
an extension that fits your need. If this is the case, you can always create your own.
Consider reading :ref:`extension-dev` to develop your own Flask extension.

.. _Flask Extension Registry: http://flask.pocoo.org/extensions/