Authentication

Learn how to create users, log in with Auth Key or Auth Token, and manage user sessions in CometChat React Native SDK.

Quick Reference - Login with Auth Key (dev) or Auth Token (production):

// Auth Key login (development only)
const user = await CometChat.login("USER_UID", "AUTH_KEY");

// Auth Token login (recommended for production)
const user = await CometChat.login("AUTH_TOKEN");

// Check existing session
const loggedInUser = await CometChat.getLoggedinUser();

Create User

Before you log in a user, you must add the user to CometChat.

1. For proof of concept/MVPs: Create the user using the CometChat Dashboard.
2. For production apps: Use the CometChat Create User API to create the user when your user signs up in your app.

Sample Users: We have set up 5 users for testing with UIDs: cometchat-uid-1, cometchat-uid-2, cometchat-uid-3, cometchat-uid-4 and cometchat-uid-5.

Once initialization is successful, you will need to log the user into CometChat using the login() method.

We recommend you call the CometChat login method once your user logs into your app. The login() method needs to be called only once.

The CometChat SDK maintains the session of the logged-in user within the SDK. Thus you do not need to call the login method for every session. You can use the CometChat.getLoggedinUser() method to check if there is any existing session in the SDK. This method should return the details of the logged-in user. If this method returns null, it implies there is no session present within the SDK and you need to log the user into CometChat.

Login using Auth Key

Security Warning: This straightforward authentication method is ideal for proof-of-concept (POC) development or during the early stages of application development. For production environments, we strongly recommend using an Auth Token instead of an Auth Key to ensure enhanced security.

JavaScript

var UID = "UID";
var authKey = "AUTH_KEY";

// Check if user is already logged in before calling login
CometChat.getLoggedinUser().then(
  (user) => {
    if (!user) {
      CometChat.login(UID, authKey).then(
        (user) => {
          console.log("Login Successful:", user);
        },
        (error) => {
          console.log("Login failed with exception:", error);
        }
      );
    }
  },
  (error) => {
    console.log("Something went wrong", error);
  }
);

TypeScript

var UID: string = "cometchat-uid-1",
  authKey: string = "AUTH_KEY";

// Check if user is already logged in before calling login
CometChat.getLoggedinUser().then(
  (user: CometChat.User) => {
    if (!user) {
      CometChat.login(UID, authKey).then(
        (user: CometChat.User) => {
          console.log("Login Successful:", user);
        },
        (error: CometChat.CometChatException) => {
          console.log("Login failed with exception:", error);
        }
      );
    }
  },
  (error: CometChat.CometChatException) => {
    console.log("Some Error Occured", error);
  }
);

Parameter	Description
UID	The UID of the user that you would like to login
authKey	CometChat Auth Key

After the user logs in, their information is returned in the User object on Promise resolved.

Response

On Success — Returns a User object:

User Object:

Parameter	Type	Description	Sample Value
uid	string	Unique identifier of the user	"cometchat-uid-2"
name	string	Display name of the user	"George Alan"
authToken	string	Authentication token for the session	"cometchat-uid-2_17713124898af10df254d51ef6ffc14e79955ac0"
avatar	string	URL to user’s avatar image	"https://assets.cometchat.io/sampleapp/v2/users/cometchat-uid-2.webp"
status	string	Current online status	"online"
role	string	User’s role	"default"
lastActiveAt	number	Unix timestamp of last activity	1771311515
hasBlockedMe	boolean	Whether this user has blocked the logged-in user	false
blockedByMe	boolean	Whether logged-in user has blocked this user	false
deactivatedAt	number	Unix timestamp if user is deactivated (0 if active)	0
tags	array	Tags associated with the user	[]

Login using Auth Token

This advanced authentication procedure does not use the Auth Key directly in your client code, thus ensuring safety.

1. Create a User

   Create a User via the CometChat API when the user signs up in your app.

2. Create an Auth Token

   Create an Auth Token via the CometChat API for the new user and save the token in your database.

3. Login with the token

   Load the Auth Token in your client and pass it to the login() method.

JavaScript

var authToken = "AUTH_TOKEN";

// Check if user is already logged in before calling login
CometChat.getLoggedinUser().then(
  (user) => {
    if (!user) {
      CometChat.login(authToken).then(
        (user) => {
          console.log("Login Successful:", user);
        },
        (error) => {
          console.log("Login failed with exception:", error);
        }
      );
    }
  },
  (error) => {
    console.log("Something went wrong", error);
  }
);

TypeScript

var authToken: string = "AUTH_TOKEN";

// Check if user is already logged in before calling login
CometChat.getLoggedinUser().then(
  (user: CometChat.User) => {
    if (!user) {
      CometChat.login(authToken).then(
        (user: CometChat.User) => {
          console.log("Login Successful:", user);
        },
        (error: CometChat.CometChatException) => {
          console.log("Login failed with exception:", error);
        }
      );
    }
  },
  (error: CometChat.CometChatException) => {
    console.log("Some Error Occured", error);
  }
);

Parameter	Description
authToken	Auth Token of the user you would like to login

After the user logs in, their information is returned in the User object on the Promise resolved.

Response

On Success — Returns a User object:

User Object:

Parameter	Type	Description	Sample Value
uid	string	Unique identifier of the user	"cometchat-uid-2"
name	string	Display name of the user	"George Alan"
authToken	string	Authentication token for the session	"cometchat-uid-2_17713124898af10df254d51ef6ffc14e79955ac0"
avatar	string	URL to user’s avatar image	"https://assets.cometchat.io/sampleapp/v2/users/cometchat-uid-2.webp"
status	string	Current online status	"online"
role	string	User’s role	"default"
lastActiveAt	number	Unix timestamp of last activity	1771311515
hasBlockedMe	boolean	Whether this user has blocked the logged-in user	false
blockedByMe	boolean	Whether logged-in user has blocked this user	false
deactivatedAt	number	Unix timestamp if user is deactivated (0 if active)	0
tags	array	Tags associated with the user	[]

Logout

You can use the logout() method to log out the user from CometChat. We suggest you call this method once your user has been successfully logged out from your app.

JavaScript

CometChat.logout().then(
  () => {
    console.log("Logout completed successfully");
  },
  (error) => {
    console.log("Logout failed with exception:", error);
  }
);

TypeScript

CometChat.logout().then(
  (loggedOut: Object) => {
    console.log("Logout completed successfully");
  },
  (error: CometChat.CometChatException) => {
    console.log("Logout failed with exception:", error);
  }
);

Response

On Success — Returns a success message:

Parameter	Type	Description	Sample Value
message	string	Logout confirmation	"Logout completed successfully"

Best Practices

• Always check for an existing session with getLoggedinUser() before calling login()
• Use Auth Token (not Auth Key) in production environments
• Generate Auth Tokens server-side and never expose your REST API Key in client code
• Call logout() when the user logs out of your app to clean up the CometChat session
• Handle login errors gracefully and provide user-friendly error messages

Troubleshooting

• Login fails with “UID not found”: Ensure the user has been created in CometChat before attempting login
• Auth Token expired: Generate a new Auth Token from your server and retry login
• Session persists after logout: Ensure logout() completes successfully before redirecting
• Multiple login calls: Use getLoggedinUser() to prevent redundant login attempts

Next Steps

Login Listener

Listen for real-time login and logout events

Send Messages

Start sending text, media, and custom messages

User Presence

Track real-time online/offline status of users

UI Kit Integration

Add pre-built UI components to your app