Extensions

Extensions are extra packages that add functionality to a Flask application. For example, an extension might add support for sending email or connecting to a database. Some extensions add entire new frameworks to help build certain types of applications, like a ReST API.

Finding Extensions

Flask extensions are usually named "Flask-Foo" or "Foo-Flask". Many extensions are listed in the Extension Registry_, which can be updated by extension developers. You can also search PyPI for packages tagged with Framework :: Flask <pypi_>_.

Using Extensions

Consult each extension's documentation for installation, configuration, and usage instructions. Generally, extensions pull their own configuration from :attr:app.config <flask.Flask.config> and are passed an application instance during initialization. For example, an extension called "Flask-Foo" might be used like this::

from flask_foo import Foo

foo = Foo()

app = Flask(__name__)
app.config.update(
    FOO_BAR='baz',
    FOO_SPAM='eggs',
)

foo.init_app(app)

Building Extensions

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

.. _Extension Registry: http://flask.pocoo.org/extensions/ .. _pypi: https://pypi.org/search/?c=Framework+%3A%3A+Flask