Twitter
=======

Twitter offers per application keys named ``Consumer Key`` and ``Consumer Secret``.
To enable Twitter these two keys are needed. Further documentation at
`Twitter development resources`_:

- Register a new application at `Twitter App Creation`_,

- Check the **Allow this application to be used to Sign in with Twitter**
  checkbox. If you don't check this box, Twitter will force your user to login
  every time.

- Fill **Consumer Key** and **Consumer Secret** values::

      SOCIAL_AUTH_TWITTER_KEY = ''
      SOCIAL_AUTH_TWITTER_SECRET = ''

- You need to specify an URL callback or the OAuth will raise a "403 Client Error".
  The callback URL should be something like "https://example.com/complete/twitter"

- You can request user's Email address (consult `Twitter verify
  credentials`_), the parameter is sent automatically, but the
  applicaton needs to be whitelisted in order to get a valid value.

- You’ll need to apply for Elevated access via the Developer Portal, see `Twitter access levels`_ for more info.

Twitter usually fails with a 401 error when trying to call the request-token
URL, this is usually caused by server datetime errors (check miscellaneous
section). Installing ``ntp`` and syncing the server date with some pool does
the trick.


.. _Twitter development resources: https://dev.twitter.com/oauth
.. _Twitter App Creation: https://apps.twitter.com/apps/new
.. _Twitter verify credentials: https://developer.twitter.com/en/docs/twitter-api/v1/accounts-and-users/manage-account-settings/api-reference/get-account-verify_credentials
.. _Twitter access levels: https://developer.twitter.com/en/docs/twitter-api/getting-started/about-twitter-api#v2-access-level