Authentication - CometChat Docs

Before users can make or receive calls, they must be authenticated with the CometChat Calls SDK. This guide covers the login and logout methods.

Sample UsersCometChat provides 5 test users: cometchat-uid-1, cometchat-uid-2, cometchat-uid-3, cometchat-uid-4, and cometchat-uid-5.

Before calling login(), check if a user is already logged in using getLoggedInUser(). The SDK maintains the session internally, so you only need to login once per user session.

Kotlin
Java

val loggedInUser = CometChatCalls.getLoggedInUser()

if (loggedInUser != null) {
    // User is already logged in
    Log.d(TAG, "User already logged in: ${loggedInUser.uid}")
} else {
    // No user logged in, proceed with login
}

CallUser loggedInUser = CometChatCalls.getLoggedInUser();

if (loggedInUser != null) {
    // User is already logged in
    Log.d(TAG, "User already logged in: " + loggedInUser.getUid());
} else {
    // No user logged in, proceed with login
}

The getLoggedInUser() method returns a CallUser object if a user is logged in, or null if no session exists. This method is suitable for development and testing. For production apps, use Auth Token login instead.

Security NoticeUsing the API Key directly in client code is not recommended for production. Use Auth Token authentication for enhanced security.

Kotlin
Java

val uid = "cometchat-uid-1" // Replace with your user's UID
val apiKey = "API_KEY" // Replace with your API Key

if (CometChatCalls.getLoggedInUser() == null) {
    CometChatCalls.login(uid, apiKey, object : CometChatCalls.CallbackListener<CallUser>() {
        override fun onSuccess(user: CallUser) {
            Log.d(TAG, "Login successful: ${user.uid}")
        }

        override fun onError(e: CometChatException) {
            Log.e(TAG, "Login failed: ${e.message}")
        }
    })
} else {
    // User already logged in
}

String uid = "cometchat-uid-1"; // Replace with your user's UID
String apiKey = "API_KEY"; // Replace with your API Key

if (CometChatCalls.getLoggedInUser() == null) {
    CometChatCalls.login(uid, apiKey, new CometChatCalls.CallbackListener<CallUser>() {
        @Override
        public void onSuccess(CallUser user) {
            Log.d(TAG, "Login successful: " + user.getUid());
        }

        @Override
        public void onError(CometChatException e) {
            Log.e(TAG, "Login failed: " + e.getMessage());
        }
    });
} else {
    // User already logged in
}

Parameter	Type	Description
`uid`	String	The unique identifier of the user to login
`apiKey`	String	Your CometChat API Key
`listener`	CallbackListener	Callback for success/error handling

This is the recommended authentication method for production applications. The Auth Token is generated server-side, keeping your API Key secure.

Auth Token Flow

User authenticates with your backend
Your backend calls the CometChat Create Auth Token API
Your backend returns the Auth Token to the client
Client uses the Auth Token to login

Kotlin
Java

val authToken = "AUTH_TOKEN" // Token received from your backend

CometChatCalls.login(authToken, object : CometChatCalls.CallbackListener<CallUser>() {
    override fun onSuccess(user: CallUser) {
        Log.d(TAG, "Login successful: ${user.uid}")
    }

    override fun onError(e: CometChatException) {
        Log.e(TAG, "Login failed: ${e.message}")
    }
})

String authToken = "AUTH_TOKEN"; // Token received from your backend

CometChatCalls.login(authToken, new CometChatCalls.CallbackListener<CallUser>() {
    @Override
    public void onSuccess(CallUser user) {
        Log.d(TAG, "Login successful: " + user.getUid());
    }

    @Override
    public void onError(CometChatException e) {
        Log.e(TAG, "Login failed: " + e.getMessage());
    }
});

Parameter	Type	Description
`authToken`	String	Auth Token generated via CometChat API
`listener`	CallbackListener	Callback for success/error handling

CallUser Object

On successful login, the callback returns a CallUser object containing user information:

Property	Type	Description
`uid`	String	Unique identifier of the user
`name`	String	Display name of the user
`avatar`	String	URL of the user’s avatar image
`status`	String	User’s online status

Logout

Call logout() when the user signs out of your application. This clears the local session and disconnects from CometChat services.

Kotlin
Java

CometChatCalls.logout(object : CometChatCalls.CallbackListener<String>() {
    override fun onSuccess(message: String) {
        Log.d(TAG, "Logout successful")
    }

    override fun onError(e: CometChatException) {
        Log.e(TAG, "Logout failed: ${e.message}")
    }
})

CometChatCalls.logout(new CometChatCalls.CallbackListener<String>() {
    @Override
    public void onSuccess(String message) {
        Log.d(TAG, "Logout successful");
    }

    @Override
    public void onError(CometChatException e) {
        Log.e(TAG, "Logout failed: " + e.getMessage());
    }
});

Error Handling

Common authentication errors:

Error Code	Description
`ERROR_INVALID_UID`	The provided UID is empty or invalid
`ERROR_UID_WITH_SPACE`	The UID contains spaces (not allowed)
`ERROR_API_KEY_NOT_FOUND`	The API Key is missing or invalid
`ERROR_BLANK_AUTHTOKEN`	The Auth Token is empty
`ERROR_LOGIN_IN_PROGRESS`	A login operation is already in progress

​Check Login Status

​Login with UID and API Key

​Login with Auth Token

​Auth Token Flow

​CallUser Object

​Logout

​Error Handling

Check Login Status

Login with UID and API Key

Login with Auth Token

Auth Token Flow

CallUser Object

Logout

Error Handling