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Version: v4


This guide demonstrates how to add chat to a Flutter application. Before you begin, we strongly recommend you read the Key Concepts guide.

I want to explore a sample app

Follow the steps mentioned in the file to run the sample app

Flutter Chat App

Get your Application Keys

Signup for CometChat and then:

  1. Create a new app
  2. Head over to the API Keys section and note the Auth Key, App ID & Region
Minimum Requirements
  • Android API Level 21
  • AndroidX Compatibility
  • iOS 11 or higher
  • Flutter SDK 1.2 or higher

Add the CometChat Dependency

  1. Add the following code in your pubspec.yaml file and run pub get command.
cometchat_sdk: ^4.0.14
  1. For iOS change iOS deployment target to 11 or higher.
  2. Add the following code to podfile inside iOS section of your app.
post_install do |installer|

installer.pods_project.targets.each do |target|


//Copy from here------->

target.build_configurations.each do |build_configuration|

build_configuration.build_settings['EXCLUDED_ARCHS[sdk=iphonesimulator*]'] = 'arm64 i386'


//Copy TILL here------->


  1. For iOS navigate to your iOS folder in terminal or CMD and do pod install . For apple chip system use rosetta terminal.
  2. import CometChat SDK using the following code in dart.
import 'package:cometchat_sdk/cometchat_sdk.dart';

Initialise CometChat

The init() method initializes the settings required for CometChat. The init() method takes the below parameters:

  1. appID - You CometChat App ID
  2. appSettings - An object of the AppSettings class can be created using the AppSettingsBuilder class. The region field is mandatory and can be set using the setRegion() method.

The AppSettings class allows you to configure three settings:

  • Region: The region where your app was created.
  • User Presence Presence Subscription: Represents the subscription type for user presence (real-time online/offline status)
  • autoEstablishSocketConnection(boolean value): This property takes a boolean value which when set to true informs the SDK to manage the web-socket connection internally. If set to false, it informs the SDK that the web-socket connection will be managed manually. The default value for this parameter is true. For more information on this, please check the Connection Behaviour section. The default value for this property is true.
  • adminHost(adminHost: string): This method takes the admin URL as input and uses this admin URL instead of the default admin URL. This can be used in case of dedicated deployment of CometChat.
  • clientHost(clientHost: string): This method takes the client URL as input and uses this client URL instead of the default client URL. This can be used in case of dedicated deployment of CometChat.
String region = "REGION";
String appId = "APP_ID";

AppSettings appSettings= (AppSettingsBuilder()
..subscriptionType = CometChatSubscriptionType.allUsers
..region= region
..adminHost = "" //optional
..clientHost = "" //optional
..autoEstablishSocketConnection = true

CometChat.init(appId, appSettings,
onSuccess: (String successMessage) {
debugPrint("Initialization completed successfully $successMessage");
}, onError: (CometChatException excep) {
debugPrint("Initialization failed with exception: ${excep.message}");

Make sure you replace the APP_ID with your CometChat App ID and region with your App Region in the above code.

Register and Login your User

Once initialization is successful, you will need to create a user.

To create users on the fly, you can use the createUser() method. This method takes an User object and the Auth Key as input parameters and returns the created User object if the request is successful.

String authKey = "AUTH_KEY";//Replace with the auth key of app
User user = User( uid: "usr1", name: "Kevin" );//Replace with name and uid of user

CometChat.createUser(user, authKey,
onSuccess: (User user){
debugPrint("Create User succesful ${user}");
}, onError: (CometChatException e){
debugPrint("Create User Failed with exception ${e.message}");

Make sure that UID and name are specified as these are mandatory fields to create a user.

Once you have created the user successfully, you will need to log the user into CometChat using the login() method.


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

String UID = "user_id"; // Replace with the UID of the user to login
String authKey = "AUTH_KEY"; // Replace with your App Auth Key

final user = await CometChat.getLoggedInUser();
if (user == null) {
await CometChat.login(UID, authKey,
onSuccess: (User user) {
debugPrint("Login Successful : $user" );
}, onError: (CometChatException e) {
debugPrint("Login failed with exception: ${e.message}");

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