Key Concepts

CometChat Dashboard

The CometChat Dashboard enables you to create new apps (projects) and manage your existing apps.

How many apps to create?

Ideally, you should create two apps- one for development and one for production. And you should use a single app irrespective of the number of platforms. > > Do not create separate apps for every platform; if you do, your users on different platforms will not be able to communicate with each other!

• For every app, a unique App ID is generated. This App ID will be required when integrating CometChat within your app.
• Along with the App ID, you will need to create an Auth Key (from the Dashboard) which can be used for user authentication.

Auth & Rest API Keys

You can generate two types of keys from the dashboard.

Type	Privileges	Recommended Use
Auth Key	The Auth Key can be used to create & login users.	In your client side code (during development)
Rest API Key	The Rest API Key can be used to perform any CometChat operation.	In your server side code

Users

A user is anyone who uses CometChat.

UID

• Each user is uniquely identified using UID.
• The UID is typically the primary ID of the user from your database.

Warning

UID can be alphanumeric with underscore and hyphen. Spaces, punctuation and other special characters are not allowed.

Auth Token

• A single user can have multiple auth tokens. The auth tokens should be per user per device.
• It should be generated by API call ideally, via server to server call. The auth token should then be given to CometChat for login.
• An Auth Token can only be deleted via dashboard or using REST API.

Authentication

To allow a user to use CometChat, the user must log in to CometChat.

CometChat does not handle user management. You must handle user registration and login at your end. Once the user is logged into your app/site, you can log in the user to CometChat programmatically. So the user does not ever directly login to CometChat.

CometChat does not handle friends management. If you want to associate friends with your users, you must handle friends management in your app. Once two users are friends (i.e. they have accepted each other as friends), then you can associate them as friends in CometChat.

Typical Workflow

Your App	Your Server	CometChat
User registers in your app	You store the user information in your database (e.g. ID, name, email, phone, location etc. in users table)	You add the user to CometChat (only ID & name) using the Rest API
User logs in to your app	You verify the credentials, login the user and retrieve the user ID	You log in the user to CometChat using the same user ID programmatically
User sends a friend request	You display the request to the potential friend	No action required
User accepts a friend request	You display the users as friends	You add both the users as friends using the Rest API

User Roles

A role is a category for a group of similar users. For example, you may want to group your premium users using the role "Premium". You then use this to filter users or enable/disable features by writing conditional code.

User List

• The User List can be used to build the Contacts or Who's Online view in your app.
• The list of users can be different based on the logged-in user.

Groups

A group can be used for multiple users to communicate with each other on a particular topic/interest.

GUID

• Each group is uniquely identified using GUID.
• The GUID is typically the primary ID of the group from your database. If you do not store group information in your database, you can generate a random string for use as GUID.

Warning

GUID can be alphanumeric with underscore and hyphen. Spaces, punctuation and other special characters are not allowed.

Types

CometChat supports three different types of groups:

Type	Visibility	Participation
Public	All users	Any user can choose to join
Password	All users	Any user with a valid password can choose to join
Private	Only users part of the group	Invited users will be auto-joined

Members

Once a participant joins a group, they become a member of the group. Members are part of the group indefinitely i.e. they will keep receiving messages, calls & notifications. To stop, the participant must either be kicked, banned or intentionally leave the group.

CometChat supports three different types of member scopes in a group:

Member	Default	Privileges
Admin	Group creator is assigned Admin scope	- Change scope of Group Members to admin, moderator or participant. - Can add members to a group. - Kick & Ban Participants/Moderators/Admins - Send & Receive Messages & Calls - Update group - Delete group
Moderator	-	- Change scope of moderator or participant. - Update group - Kick & Ban Participants - Send & Receive Messages & Calls
Participant	Any other user is assigned Participant scope	- Send & Receive Messages & Calls

Messaging

Any message in CometChat can belong to either one of the below categories

Category	Description
message	Any message belonging to the category message can belong to either one of the below types: 1. text 2. image 3. video 4. audio 5. file
custom	Custom messages are an option available for developers to send custom data across to users/groups. To send any additional data that does not fit in the default categories and types provided by CometChat, you can use the custom messages.
action	Action messages are system-generated messages. These can belong to either of the below types:1. groupMember - when the action is performed on a group member 2. message - when the action is performed on a message
call	These are call-related messages. These can belong to either one of the two types:1. audio 2. video

For more information, you can refer to the Message structure and hierarchy guide.