<a id="discourse"></a>

# Discourse

<a id="backend-class"></a>

## Backend class

For Django, add this class path to `AUTHENTICATION_BACKENDS`. For other
integrations, use the same class path in the framework-specific backend
setting.

| Backend name   | Class path                                     |
|----------------|------------------------------------------------|
| `discourse`    | `social_core.backends.discourse.DiscourseAuth` |

Discourse can serve as a Single Sign On provider for Authentication.

The backend binds the local association to Discourse’s `external_id`. Email
addresses remain profile data and are not account identifiers because they can
change or later belong to another user.

Discourse authentication must finish in the browser session that started it.
If the session is lost before the Discourse callback, the login fails and the
user must start again. Logins already in progress when upgrading to a version
that enforces this check must also be restarted.

- Deploy a Discourse application and configure
  <https://meta.discourse.org/t/using-discourse-as-a-sso-provider/32974> the
  application to enable Discourse as an SSO provider.
- Fill in the shared secret and url of the Discourse server in the settings:
  ```default
  SOCIAL_AUTH_DISCOURSE_SECRET = "myDiscourseSecret"
  SOCIAL_AUTH_DISCOURSE_SERVER_URL = "https://my-discourse-site.com"
  ```

<a id="using-multiple-discourse-instances"></a>

## Using multiple Discourse instances

Since Discourse is a distributed application, multiple Discourse instances can
be used as SSO providers. If this is the case, the DiscourseAuth class can be
extended and configured as follows:

```default
from social_core.backends.discourse import DiscourseAuth

class DiscourseAuthFoo(DiscourseAuth):
    name = 'discourse-foo'

class DiscourseAuthBar(DiscourseAuth):
    name = 'discourse-bar'
```

Fill in the settings like so:

```default
SOCIAL_AUTH_DISCOURSE_FOO_SECRET = "myDiscourseFooSecret"
SOCIAL_AUTH_DISCOURSE_FOO_SERVER_URL = "https://my-discourse-foo-site.com"
SOCIAL_AUTH_DISCOURSE_BAR_SECRET = "myDiscourseBarSecret"
SOCIAL_AUTH_DISCOURSE_BAR_SERVER_URL = "https://my-discourse-bar-site.com"
```

<a id="external-memberships"></a>

## External memberships

See [External groups](../groups.html.md) for opt-in extraction, group-based login restrictions, and
local group synchronization. No separate extraction pipeline step is needed.