omniauth-facebook2 provides a Facebook OAuth2 strategy for OmniAuth.

Add this line to your application's Gemfile:

gem 'omniauth-facebook2'

Then run:

bundle install

Configure OmniAuth in your Rack/Rails app:

Rails.application.config.middleware.use OmniAuth::Builder do
  provider :facebook2,
           ENV.fetch('FACEBOOK_APP_ID'),
           ENV.fetch('FACEBOOK_APP_SECRET'),
           api_version: 'v26.0' # optional; default is v25.0
end

Compatibility alias is available, so existing callback paths can keep using facebook:

Rails.application.config.middleware.use OmniAuth::Builder do
  provider :facebook,
           ENV.fetch('FACEBOOK_APP_ID'),
           ENV.fetch('FACEBOOK_APP_SECRET')
end

• Meta for Developers: https://developers.facebook.com/apps/
• Facebook Login docs: https://developers.facebook.com/docs/facebook-login/
• Register callback URL (example): https://your-app.example.com/auth/facebook/callback

Supported request/provider options include:

• scope (default: email)
• api_version (default: v25.0)
• display
• auth_type (example: rerequest)
• config_id (Facebook Login for Business)
• redirect_uri
• info_fields (default: name,email)
• locale
• image_size (symbol/string like :normal, or hash { width:, height: })
• secure_image_url (default: true)
• callback_url / callback_path

If you need full endpoint control, client_options still works and takes precedence over api_version:

provider :facebook2,
         ENV.fetch('FACEBOOK_APP_ID'),
         ENV.fetch('FACEBOOK_APP_SECRET'),
         client_options: {
           site: 'https://graph.facebook.com/v26.0',
           authorize_url: 'https://www.facebook.com/v26.0/dialog/oauth',
           token_url: 'oauth/access_token'
         }

Example payload from request.env['omniauth.auth'] (captured from a real smoke run):

{
  "uid": "12345678901234567",
  "info": {
    "email": "sample.user@example.test",
    "name": "Sample User",
    "image": "https://graph.facebook.com/v25.0/12345678901234567/picture"
  },
  "credentials": {
    "token": "[REDACTED]",
    "expires_at": 1777885934,
    "expires": true
  },
  "extra": {
    "raw_info": {
      "name": "Sample User",
      "email": "sample.user@example.test",
      "id": "12345678901234567"
    }
  }
}

bundle install
bundle exec rake

Run Rails integration tests with an explicit Rails version:

RAILS_VERSION='~> 8.1.0' bundle install
RAILS_VERSION='~> 8.1.0' bundle exec rake test_rails_integration

• Ruby: >= 3.2 (tested on 3.2, 3.3, 3.4, 4.0)
• omniauth-oauth2: >= 1.8, < 2.0
• Rails integration lanes: ~> 7.1.0, ~> 7.2.0, ~> 8.0.0, ~> 8.1.0

Default endpoints target Facebook Graph API v25.0 (or vX.Y set via api_version):

• Authorize: https://www.facebook.com/vX.Y/dialog/oauth
• Token: https://graph.facebook.com/vX.Y/oauth/access_token
• User info: https://graph.facebook.com/vX.Y/me

• test/omniauth_facebook2_test.rb: strategy/unit behavior
• test/rails_integration_test.rb: full Rack/Rails request+callback flow
• test/test_helper.rb: shared test bootstrap

Tag releases as vX.Y.Z; GitHub Actions publishes the gem to RubyGems.

MIT