Web

React UI Kit Sample App

Reference implementation of React UI Kit, FCM and Push Notification Setup.

What this guide covers

Prerequisite: the shared dashboard + Firebase web config/VAPID setup in the Getting Started guide.
Service worker + Firebase Messaging wiring for foreground/background pushes.
Token registration/unregistration with CometChatNotifications and navigation on notification click.
Testing and troubleshooting tips for web push.

How CometChat + FCM work on web

Provider ID: Tells CometChat which Firebase credentials to use when sending to your web app.
Tokens: getToken returns a browser token (per origin/device). Register it after login: CometChatNotifications.registerPushToken(token, CometChatNotifications.PushPlatforms.FCM_WEB, providerId).
Handlers: Foreground messages come via messaging.onMessage; background uses firebase-messaging-sw.js with onBackgroundMessage.
Navigation: Service worker sends a postMessage or focuses the client; the app routes to the right view.

Complete the Getting Started guide first — enable Push Notifications, add your FCM provider, and set up your Firebase web app config and VAPID key. This guide covers only the web app wiring.

1. Install dependencies

Install firebase SDK:

npm install firebase@^10.3.1

2. Constants

File: src/AppConstants.js (or equivalent) Set the CometChat Constants from your dashboard and Firebase config + VAPID key.

export const COMETCHAT_CONSTANTS = {
  APP_ID: "",
  REGION: "",
  AUTH_KEY: "",
  FCM_PROVIDER_ID: "",
};

export const FIREBASE_CONFIG = { 
  apiKey: "",
  authDomain: "",
  projectId: "",
  storageBucket: "",
  messagingSenderId: "",
  appId: "",
  measurementId: ""
};

export const FIREBASE_VAPID_KEY = "";

3. Configure Firebase (frontend)

File: src/firebase.js (or equivalent) This code:

Initializes Firebase app and messaging.
Requests notification permission, fetches FCM token, and registers it with CometChat after login.
Sets up foreground message handler to show notifications.

import { initializeApp } from "firebase/app";
import { getMessaging, getToken, onMessage } from "firebase/messaging";
import { CometChatNotifications } from "@cometchat/chat-sdk-javascript";
import { COMETCHAT_CONSTANTS, FIREBASE_CONFIG, FIREBASE_VAPID_KEY } from "./AppConstants";

let messagingInstance = null;

export default async function firebaseInitialize(navigate) {
  try {
    // Check if Firebase is already initialized
    let app;
    try {
      app = initializeApp(FIREBASE_CONFIG);
    } catch (error) {
      // Firebase might already be initialized
      const { getApps } = await import("firebase/app");
      const apps = getApps();
      if (apps.length > 0) {
        app = apps[0];
      } else {
        throw error;
      }
    }

    messagingInstance = getMessaging(app);

    // Check notification permission first
    if (Notification.permission === "default") {
      return;
    }

    if (Notification.permission !== "granted") {
      return;
    }

    // Get FCM token
    const currentToken = await getToken(messagingInstance, {
      vapidKey: FIREBASE_VAPID_KEY,
    });

    if (currentToken) {
      
      // Check if user is logged in before registering
      const { CometChat } = await import("@cometchat/chat-sdk-javascript");
      const loggedInUser = await CometChat.getLoggedinUser();
      
      if (!loggedInUser) {
        return;
      }

      // Register push token with CometChat
      try {
        const payload = await CometChatNotifications.registerPushToken(
          currentToken,
          CometChatNotifications.PushPlatforms.FCM_WEB,
          COMETCHAT_CONSTANTS.FCM_PROVIDER_ID
        );
      } catch (err) {
        console.error("Firebase initialization error:", err);
      }
    } else {
      console.error("No registration token available. Request permission to generate one.");
    }
  } catch (err) {
    console.error("Firebase initialization error:", err);
  }

  // Set up foreground message handler
  if (messagingInstance) {
    onMessage(messagingInstance, function (payload) {
    
    // Show notification when app is in foreground
    if (Notification.permission === "granted") {
      const notificationTitle = payload.data?.title || "New Message";
      let notificationBody = payload.data?.body || "";
      
      // Handle call notifications
      if (payload.data?.type === "call") {
        switch (payload.data.callAction) {
          case "cancelled":
            notificationBody = "Call cancelled";
            break;
          case "initiated":
            notificationBody = `Incoming ${payload.data.callType} call`;
            break;
          default:
            break;
        }
      }
      
      const notificationOptions = {
        body: notificationBody,
        icon: payload.data?.senderAvatar || "/logo192.png",
        data: payload.data,
        tag: payload.data?.tag,
        requireInteraction: false,
      };
      
      new Notification(notificationTitle, notificationOptions);
    }
    });
  }
}

// Function to register push token after login
export async function registerPushTokenAfterLogin() {
  if (!messagingInstance) {
    return;
  }

  try {
    const currentToken = await getToken(messagingInstance, {
      vapidKey: FIREBASE_VAPID_KEY,
    });

    if (currentToken) {
      const payload = await CometChatNotifications.registerPushToken(
        currentToken,
        CometChatNotifications.PushPlatforms.FCM_WEB,
        COMETCHAT_CONSTANTS.FCM_PROVIDER_ID
      );
    }
  } catch (err) {
    console.error("Error registering push token after login:", err);
  }
}

Use your VAPID key in getToken calls.

4. Service worker (background pushes)

File: public/firebase-messaging-sw.js This code:

Initializes Firebase app in the service worker.
Handles background messages with onBackgroundMessage.
Manages notification clicks to focus the app and send data for navigation.
Ensure your app registers the service worker (e.g., in index.tsx) and listens for message events to navigate.

/* eslint-disable no-restricted-globals */
/* eslint-disable no-undef */
// required to setup background notification handler when browser is not in focus or in background and
// In order to receive the onMessage event,  app must define the Firebase messaging service worker
// self.importScripts("localforage.js");

importScripts(
  "https://www.gstatic.com/firebasejs/9.15.0/firebase-app-compat.js"
);
importScripts(
  "https://www.gstatic.com/firebasejs/9.15.0/firebase-messaging-compat.js"
);
var TAG = "[Firebase-sw.js]";

self.addEventListener("notificationclick", async function (event) {
  console.log(TAG, "notificationclick", event, event.clientId);
  if (event?.notification?.data) {
    let data = event.notification.data;
    event.waitUntil(
      self.clients
        .matchAll({ type: "window", includeUncontrolled: true })
        .then((clientList) => {
          if (clientList.length > 0) {
            clientList[0].postMessage({
              message: data,
            });
            return (
              clientList[0]
                .focus()
                .catch((error) => {
                  console.log(error);
                  return self.clients.openWindow(clientList[0].url); // Adjust this URL as necessary for your application
                })
            );
          } else {
            // Open a new client (tab) if there are no existing clients
            self.clients.openWindow("/");
            setTimeout(() => {
              self.clients
                .matchAll({ type: "window", includeUncontrolled: true })
                .then((clientList) => {
                  if (clientList.length > 0) {
                    clientList[0].postMessage({
                      message: {...data,fromBackground: true},
                    });
                  }
                  return;
                });
            }, 1500);
          }
        })
    );
  }

  event.notification.close();
});
// "Default" Firebase configuration (prevents errors)
const defaultConfig = {
  apiKey: true,
  projectId: true,
  messagingSenderId: true,
  appId: true,
};

// Initialize Firebase app
firebase.initializeApp(self.firebaseConfig || defaultConfig);
let messaging;
try {
  messaging = firebase.messaging();
  // Customize background notification handling here
  messaging.onBackgroundMessage((payload) => {
    console.log("Background Message:", payload);
    const notificationTitle = payload.data.title;
    if (
      payload.data.type === "call" &&
      (payload.data.callAction === "unanswered" ||
        payload.data.callAction === "busy" ||
        payload.data.callAction === "ongoing")
    ) {
      return;
    }
    let body = payload.data.body;
    if (payload.data.type === "call") {
      switch (payload.data.callAction) {
        case "cancelled":
          body = `Call cancelled`;
          break;
        case "initiated":
          body = `Incoming ${payload.data.callType} call`;
          break;
        default:
          break;
      }
    }
    const notificationOptions = {
      title: payload.data.title,
      icon: payload.data.senderAvatar,
      data: payload.data,
      tag: payload.data.tag,
      body: body,
    };
    self.registration.showNotification(notificationTitle, notificationOptions);
  });
} catch (err) {
  console.error("Failed to initialize Firebase Messaging", err);
}

Ensure your app registers the service worker (e.g., in index.tsx) and listens for message events to navigate. In your app initialization (e.g., App.tsx): This code:

Requests notification permission.
Fetches FCM token and registers it with CometChat after user login.
Handles token refresh by re-registering if it changes.

const token = await getToken(messaging, { vapidKey: VAPID_KEY });
await CometChatNotifications.registerPushToken(
  token,
  CometChatNotifications.PushPlatforms.FCM_WEB,
  COMETCHAT_CONSTANTS.FCM_PROVIDER_ID
);

Run after the user logs in; retry on failure.
On logout: CometChatNotifications.unregisterPushToken() before ending the session.
Handle token refresh by calling getToken again and re-registering if it changes.

Example Implementation: This code:

Initializes CometChat UI Kit.
Initializes Firebase messaging.
Logs in the user if not already logged in.
Mounts the React app.
Registers the push token after login.

import { StrictMode } from "react";
import { createRoot } from "react-dom/client";
import "./index.css";
import App from "./App.tsx";
import { COMETCHAT_CONSTANTS } from "./AppConstants.ts";

import { CometChatUIKit, UIKitSettingsBuilder } from "@cometchat/chat-uikit-react";

// Your firebase helper (from firebase.js)
// Adjust the path if your file lives somewhere else.
import firebaseInitialize, { registerPushTokenAfterLogin } from "./firebase";

const UID = "cometchat-uid-1";

/**
 * Configure the CometChat UI Kit using the UIKitSettingsBuilder.
 */
const UIKitSettings = new UIKitSettingsBuilder()
  .setAppId(COMETCHAT_CONSTANTS.APP_ID)
  .setRegion(COMETCHAT_CONSTANTS.REGION)
  .setAuthKey(COMETCHAT_CONSTANTS.AUTH_KEY)
  .subscribePresenceForAllUsers()
  .build();

function mountApp() {
  createRoot(document.getElementById("root")!).render(
    <StrictMode>
      <App />
    </StrictMode>
  );
}

async function boot() {
  try {
    // 1) Init CometChat UIKit
    await CometChatUIKit.init(UIKitSettings);
    console.log("CometChat UI Kit initialized successfully.");

    // 2) Init Firebase messaging + foreground handlers once
    // (This sets up messagingInstance and onMessage handler in your firebase.js)
    await firebaseInitialize();

    // 3) Login if needed
    const existing = await CometChatUIKit.getLoggedinUser();
    if (!existing) {
      const user = await CometChatUIKit.login(UID);
      console.log("Login Successful:", { user });
    } else {
      console.log("User already logged in:", { user: existing });
    }

    // 4) Mount UI (don’t block UI on push)
    mountApp();

    // 5) Register push AFTER login (requests permission if needed)
    // Non-blocking so app loads even if user denies permission
    void registerPushTokenAfterLogin();
  } catch (error) {
    console.error("CometChat UI Kit initialization/login failed:", error);
  }
}

boot();

6. Foreground + background handling

Foreground: messaging.onMessage → show a Notification or in-app toast; deep link using payload data.
Background/killed: service worker onBackgroundMessage shows the notification; notificationclick focuses the tab and sends a message for navigation.
Suppress duplicates if the conversation is already active.

7. Testing checklist

Service worker registered (DevTools → Application → Service Workers shows “activated”).
Permission prompt appears and is granted (Notification.permission === "granted").
Login → token fetched → registerPushToken succeeds (check console/logs).
Foreground message shows a notification; click navigates to the right chat.
Background/tab inactive message shows a notification; click focuses tab and routes correctly.
Logout → unregisterPushToken runs without errors.

8. Troubleshooting

Symptom	Quick checks
No notification	Service worker registered? Permission granted? VAPID key matches Firebase project? FCM Provider ID set in code?
Token registration fails	Run after login; confirm Provider ID; ensure correct Firebase config domain/origin; check console errors.
Click does nothing	Ensure `notificationclick` handler posts a message or opens the client; app listens for postMessage to navigate.
Foreground only	Verify `onBackgroundMessage` in service worker; confirm service worker file is in `/public` and registered.
Wrong project	Config/VAPID from a different Firebase project will invalidate tokens—recreate tokens after updating.

Overview

Platform Integrations

Settings

React UI Kit Sample App

What this guide covers

How CometChat + FCM work on web

1. Install dependencies

2. Constants

3. Configure Firebase (frontend)

4. Service worker (background pushes)

6. Foreground + background handling

7. Testing checklist

8. Troubleshooting

React UI Kit Sample App

​What this guide covers

​How CometChat + FCM work on web

​1. Install dependencies

​2. Constants

​3. Configure Firebase (frontend)

​4. Service worker (background pushes)

​5. Request permission + register token after login

​6. Foreground + background handling

​7. Testing checklist

​8. Troubleshooting

What this guide covers

How CometChat + FCM work on web

1. Install dependencies

2. Constants

3. Configure Firebase (frontend)

4. Service worker (background pushes)

5. Request permission + register token after login

6. Foreground + background handling

7. Testing checklist

8. Troubleshooting