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Integrate with Mastodon

Support level: Community

What is Mastodon​

Mastodon is free and open-source software for running self-hosted social networking services. It has microblogging features similar to Twitter

-- https://joinmastodon.org/

Preparation​

The following placeholders are used in this guide:

  • mastodon.company is the FQDN of the mastodon installation.
  • authentik.company is the FQDN of the authentik installation.
note

This documentation lists only the settings that you need to change from their default values. Be aware that any changes other than those explicitly mentioned in this guide could cause issues accessing your application.

authentik configuration​

To support the integration of Mastodon with authentik, you need to create an application/provider pair in authentik.

Create an application and provider in authentik​

  1. Log in to authentik as an admin, and open the authentik Admin interface.
  2. Navigate to Applications > Applications and click Create with Provider to create an application and provider pair. (Alternatively you can first create a provider separately, then create the application and connect it with the provider.)
  • Application: provide a descriptive name, an optional group for the type of application, the policy engine mode, and optional UI settings.
  • Choose a Provider type: select OAuth2/OpenID Connect as the provider type.
  • Configure the Provider: provide a name (or accept the auto-provided name), the authorization flow to use for this provider, and the following required configurations.
    • Note the Client ID,Client Secret, and slug values because they will be required later.
    • Set a Strict redirect URI to https://mastodon.company/auth/auth/openid_connect/callback.
    • Select any available signing key.
  • Configure Bindings (optional): you can create a binding (policy, group, or user) to manage the listing and access to applications on a user's My applications page.
  1. Click Submit to save the new application and provider.

Mastodon configuration​

Configure Mastodon OIDC_ settings by editing the .env.production and add the following:

warning

When using preferred_username as the user identifier, ensure that the Allow users to change username setting is disabled to prevent authentication issues.

info

You can configure Mastodon to use either the sub or preferred_username as the UID field under OIDC_UID_FIELD. The sub option uses a unique, stable identifier for the user, while preferred_username uses the username configured in authentik.

OIDC_ENABLED=true
OIDC_DISPLAY_NAME=authentik
OIDC_DISCOVERY=true
OIDC_ISSUER=< OpenID Configuration Issuer>
OIDC_AUTH_ENDPOINT=https://authentik.company/application/o/authorize/
OIDC_SCOPE=openid,profile,email
OIDC_UID_FIELD=preferred_username
OIDC_CLIENT_ID=<Client ID>
OIDC_CLIENT_SECRET=<Client Secret>
OIDC_REDIRECT_URI=https://mastodon.company/auth/auth/openid_connect/callback
OIDC_SECURITY_ASSUME_EMAIL_IS_VERIFIED=true

Restart mastodon-web.service

Additional Resources​