Central Authentication Service allows members to use one set of credentials to sign in to multiple sites over multiple protocols
Central Authentication Service (CAS) allows users to use one set of credentials to sign in to many sites over many different protocols.
Rocket.Chat includes a CAS plugin that allows you to use your existing CAS server for user authentication.
For more information on CAS, see

Rocket.Chat CAS Administration

To access this setting, go to Administration > Workspace > Settings > CAS.
Remember to hit Save Changes in order to apply any changes made.
Your Rocket.Chat instance is the CAS client. You must provide a compatible CAS Server.
Once you know your CAS server's URL, proceed with the settings.
The /cas and /cas/login URLs are the standard, but not required. Check with your CAS server provider if the defaults do not work.
  • Trust CAS username: When enabled, Rocket.Chat will trust that any username from CAS belongs to the same user on Rocket.Chat. This may be needed if a user is renamed on CAS, but may also allow people to take control of Rocket.Chat accounts by renaming their own CAS users.
  • Allow user creation: Allows CAS User creation from data provided by the CAS ticket when enabled.

Attribute Handling

  • Always Sync User Data: When set to true, it synchronizes external CAS User data into available attributes upon login. Note: Attributes are always synced upon account creation anyway.
  • Attribute Map: Use this JSON input to build internal attributes (key) from external attributes (value). External attribute names enclosed with '%' will be interpolated in value strings.
    Example, {"email":"%email%", "name":"%firstname%, %lastname%"}
    The attribute map is always interpolated. In CAS 1.0 only the username attribute is available. Available internal attributes are: username, name, email, rooms; rooms is a comma-separated list of rooms to join upon user creation e.g: {"rooms": "%team%,%department%"} would join CAS users on creation to their team and department channel.

CAS Login Layout

  • Login Popup Width: Lets you set the width in px of the popup screen during login.
  • Login Popup Height: This lets you set the popup height in px.
  • Login Button Label: Set the button's label.
  • Login Button Text Color: Sets the login button text color from existing variable.
  • Login Button Background Color: Sets the background color of the login button.
  • Autoclose Login Popup: When enabled, the popup will automatically close after authenticating.
After configuring, your registration and login pages will have the CAS button present.
  • CAS by ja-sig requires ssl/tls for all connections.
  • Any Drupal 7 or 8 sites can serve as a compatible CAS Server. See