Here you can see the full list of changes between each Flask release.
Release date to be announced, codename to be selected
- Added :meth:`~flask.Flask.make_default_options_response`
which can be used by subclasses to alter the default
behaviour for `OPTIONS` responses.
- Unbound locals now raise a proper :exc:`RuntimeError` instead
of an :exc:`AttributeError`.
- Mimetype guessing and etag support based on file objects is now
deprecated for :func:`flask.send_file` because it was unreliable.
Pass filenames instead or attach your own etags and provide a
proper mimetype by hand.
- Static file handling for modules now requires the name of the
static folder to be supplied explicitly. The previous autodetection
was not reliable and caused issues on Google's App Engine. Until
1.0 the old behaviour will continue to work but issue dependency
- fixed a problem for Flask to run on jython.
- added a `PROPAGATE_EXCEPTIONS` configuration variable that can be
used to flip the setting of exception propagation which previously
was linked to `DEBUG` alone and is now linked to either `DEBUG` or
- Flask no longer internally depends on rules being added through the
`add_url_rule` function and can now also accept regular werkzeug
rules added to the url map.
- Added an `endpoint` method to the flask application object which
allows one to register a callback to an arbitrary endpoint with
Bugfix release, released on December 31st 2010
- Fixed an issue where the default `OPTIONS` response was
not exposing all valid methods in the `Allow` header.
- Jinja2 template loading syntax now allows "./" in front of
a template load path. Previously this caused issues with
- Fixed an issue where the subdomain setting for modules was
ignored for the static folder.
- Fixed a security problem that allowed clients to download arbitrary files
if the host server was a windows based operating system and the client
uses backslashes to escape the directory the files where exposed from.
Released on July 27th 2010, codename Whisky
- after request functions are now called in reverse order of
- OPTIONS is now automatically implemented by Flask unless the
application explicitly adds 'OPTIONS' as method to the URL rule.
In this case no automatic OPTIONS handling kicks in.
- static rules are now even in place if there is no static folder
for the module. This was implemented to aid GAE which will
remove the static folder if it's part of a mapping in the .yml
- the :attr:`~flask.Flask.config` is now available in the templates
- context processors will no longer override values passed directly
to the render function.
- added the ability to limit the incoming request data with the
new ``MAX_CONTENT_LENGTH`` configuration value.
- the endpoint for the :meth:`flask.Module.add_url_rule` method
is now optional to be consistent with the function of the
same name on the application object.
- added a :func:`flask.make_response` function that simplifies
creating response object instances in views.
- added signalling support based on blinker. This feature is currently
optional and supposed to be used by extensions and applications. If
you want to use it, make sure to have `blinker`_ installed.
- refactored the way URL adapters are created. This process is now
fully customizable with the :meth:`~flask.Flask.create_url_adapter`
- modules can now register for a subdomain instead of just an URL
prefix. This makes it possible to bind a whole module to a
.. _blinker: http://pypi.python.org/pypi/blinker
Bugfix Release, released on July 15th 2010
- fixed another issue with loading templates from directories when
modules were used.
Bugfix Release, released on July 6th 2010
- fixes an issue with template loading from directories when modules
Released on July 6th 2010, codename Calvados
- fixed a bug with subdomains that was caused by the inability to
specify the server name. The server name can now be set with
the `SERVER_NAME` config key. This key is now also used to set
the session cookie cross-subdomain wide.
- autoescaping is no longer active for all templates. Instead it
is only active for ``.html``, ``.htm``, ``.xml`` and ``.xhtml``.
Inside templates this behaviour can be changed with the
- refactored Flask internally. It now consists of more than a
- :func:`flask.send_file` now emits etags and has the ability to
do conditional responses builtin.
- (temporarily) dropped support for zipped applications. This was a
rarely used feature and led to some confusing behaviour.
- added support for per-package template and static-file directories.
- removed support for `create_jinja_loader` which is no longer used
in 0.5 due to the improved module support.
- added a helper function to expose files from any directory.
Released on June 18th 2010, codename Rakia
- added the ability to register application wide error handlers
- :meth:`~flask.Flask.after_request` handlers are now also invoked
if the request dies with an exception and an error handling page
- test client has not the ability to preserve the request context
for a little longer. This can also be used to trigger custom
requests that do not pop the request stack for testing.
- because the Python standard library caches loggers, the name of
the logger is configurable now to better support unittests.
- added `TESTING` switch that can activate unittesting helpers.
- the logger switches to `DEBUG` mode now if debug is enabled.
Bugfix release, released on May 28th 2010
- fixed a error reporting bug with :meth:`flask.Config.from_envvar`
- removed some unused code from flask
- release does no longer include development leftover files (.git
folder for themes, built documentation in zip and pdf file and
some .pyc files)
Released on May 28th 2010, codename Schnaps
- added support for categories for flashed messages.
- the application now configures a :class:`logging.Handler` and will
log request handling exceptions to that logger when not in debug
mode. This makes it possible to receive mails on server errors
- added support for context binding that does not require the use of
the with statement for playing in the console.
- the request context is now available within the with statement making
it possible to further push the request context or pop it.
- added support for configurations.
Released on May 12th 2010, codename Jägermeister
- various bugfixes
- integrated JSON support
- added :func:`~flask.get_template_attribute` helper function.
- :meth:`~flask.Flask.add_url_rule` can now also register a
- refactored internal request dispatching.
- server listens on 127.0.0.1 by default now to fix issues with chrome.
- added external URL support.
- added support for :func:`~flask.send_file`
- module support and internal request handling refactoring
to better support pluggable applications.
- sessions can be set to be permanent now on a per-session basis.
- better error reporting on missing secret keys.
- added support for Google Appengine.
First public preview release.