Permissions

When you develop a chat app, you might want to set rules that let only selected users access specific channels and user metadata. You can set up a detailed permission schema for your application and decide who can do what with your data. This way, you secure and protect your application against unauthorized third-party access attempts.

For example, you can let only specific users modify public channel information or profiles of other chat users. You can also let only admins remove users from channels for offensive behavior.

Unreal Chat SDK, as a purely client-side library, doesn't do anything specific to handle such permissions internally, apart from imposing some limits through client-side errors:

• The allowed channel membership (direct, group, or public channel types).
• Availability of specific features in public chats (you'll get errors when implementing such Unreal Chat SDK features as typing indicator, invites, or read receipts).

Still, you can use the cryptographic, token-based permission administrator from PubNub called Access Manager to impose strict access rules for PubNub resources in your app.

We recommend that you use Unreal SDK's Access Manager for server-side operations although you any PubNub SDK that supports Access Manager will do.

Required configuration

Before you start using Access Manager, you must configure your app:

1. Enable Access Manager on your app's keyset in the Admin Portal.

2. Initialize the Unreal SDK:

• With the Secret Key on your servers to secure your PubNub instance. Secret Key is a shared secret between your application's server and PubNub and it's used to administer Access Manager permissions for your client applications by signing and verifying the authenticity of messages and requests. Read Moderation for examples.

Secret key security

The Secret Key should only be used within a secure server and never exposed to client devices. If the Secret Key is ever compromised, it can be an extreme security risk to your application. If you suspect your Secret Key has been compromised, you can generate a new Secret Key for the existing PubNub keyset on the Admin Portal.

1. Initialize the Unreal Chat SDK (Init()):

• With the Auth Key on your clients to authenticate users in your application and grant them access to PubNub resources (other users' metadata and channels). Read Moderation for examples.

Use Access Manager

To implement access rules in your app, refer to Access Manager API using these Unreal SDK methods:

• GrantToken() to generate a time-limited authorization token with an embedded access control list.

  Channel group limitation

  Unreal Chat SDK doesn't support channel groups, so you can only set permissions for the channels and users.

• RevokeToken() to disable an existing token and revoke all permissions embedded within.

• ParseToken() to decode an existing token and return the object containing permissions embedded in that token.

• SetToken() to update the authentication token granted by the server.

Resource permissions

You can use Access Manager in the Unreal SDK to define what operations (like read, write, or get) your chat app users can do with such PubNub resources as channels (channels) and other users' metadata (uuids):

Resource type	Permissions
channels	read, write, get, manage, update, join, delete
uuids	get, update, delete

Read the Moderation documentation to learn how you can mute and ban users in your chat app and secure these restrictions with Access Manager.

Check for permissions

You can use the AccessManager->CanI() method to check if the current user has permissions for particular operations on a specific resource. For more information, refer to Token permissions.