Skip to main content
Quick Reference for AI Agents & Developers
// Configure presence during init
const appSettings = new CometChat.AppSettingsBuilder()
  .subscribePresenceForAllUsers()  // or subscribePresenceForRoles(["admin"])
  .setRegion(region)
  .build();
await CometChat.init(appID, appSettings);

// Listen for presence changes
CometChat.addUserListener("PRESENCE_LISTENER", new CometChat.UserListener({
  onUserOnline: (user) => console.log(user.getName(), "is online"),
  onUserOffline: (user) => {
    console.log(user.getName(), "went offline");
    console.log("Last seen:", user.getLastActiveAt());
  }
}));

// Check user status
const user = await CometChat.getUser("user_uid");
const status = user.getStatus();  // "online" or "offline"
const lastActive = user.getLastActiveAt();  // Unix timestamp
User presence shows whether users are currently online and available to chat. CometChat provides real-time presence updates and last-seen timestamps.
Availability: SDK, API, UI KitsPresence must be configured during SDK initialization.

​
Configure Presence Subscription

Set up presence subscription when initializing the SDK using AppSettingsBuilder: 
const appSettings = new CometChat.AppSettingsBuilder()
  .subscribePresenceForAllUsers()
  .setRegion(region)
  .autoEstablishSocketConnection(true)
  .build();

CometChat.init(appID, appSettings);
MethodDescription
subscribePresenceForAllUsers()Receive presence for all users
subscribePresenceForRoles(roles)Receive presence for users with specific roles
subscribePresenceForFriends()Receive presence for friends only
If no presence method is called, no presence updates will be received.

​
Listen for Presence Changes

Register a listener to receive real-time presence updates: 
const listenerID = "PRESENCE_LISTENER";

CometChat.addUserListener(
  listenerID,
  new CometChat.UserListener({
    onUserOnline: (user) => {
      console.log(`${user.getName()} is now online`);
    },
    onUserOffline: (user) => {
      console.log(`${user.getName()} went offline`);
      console.log("Last seen:", user.getLastActiveAt());
    }
  })
);

​
Remove Listener

CometChat.removeUserListener("PRESENCE_LISTENER");

​
Check User Status

When fetching users, check their presence status: 
const user = await CometChat.getUser("user1");

// Get current status
const status = user.getStatus();  // "online" or "offline"

// Get last active timestamp (when offline)
const lastActive = user.getLastActiveAt();

if (status === "online") {
  console.log("User is online");
} else {
  const lastSeen = new Date(lastActive * 1000);
  console.log("Last seen:", lastSeen.toLocaleString());
}

​
User Status Properties

PropertyTypeDescription
statusString"online" or "offline"
lastActiveAtNumberUnix timestamp of last activity

​
Implementation Example

class PresenceManager {
  constructor() {
    this.onlineUsers = new Set();
    this.listenerID = "presence-manager";
  }

  initialize() {
    CometChat.addUserListener(
      this.listenerID,
      new CometChat.UserListener({
        onUserOnline: (user) => this.handleOnline(user),
        onUserOffline: (user) => this.handleOffline(user)
      })
    );
  }

  handleOnline(user) {
    this.onlineUsers.add(user.getUid());
    this.updateUI(user.getUid(), "online");
  }

  handleOffline(user) {
    this.onlineUsers.delete(user.getUid());
    this.updateUI(user.getUid(), "offline", user.getLastActiveAt());
  }

  isOnline(uid) {
    return this.onlineUsers.has(uid);
  }

  updateUI(uid, status, lastActive = null) {
    // Update your UI here
    console.log(`${uid} is now ${status}`);
    if (lastActive) {
      console.log("Last seen:", new Date(lastActive * 1000));
    }
  }

  formatLastSeen(timestamp) {
    if (!timestamp) return "Unknown";
    
    const now = Date.now();
    const diff = now - timestamp * 1000;
    
    const minutes = Math.floor(diff / 60000);
    const hours = Math.floor(diff / 3600000);
    const days = Math.floor(diff / 86400000);
    
    if (minutes < 1) return "Just now";
    if (minutes < 60) return `${minutes}m ago`;
    if (hours < 24) return `${hours}h ago`;
    return `${days}d ago`;
  }

  cleanup() {
    CometChat.removeUserListener(this.listenerID);
  }
}

// Usage
const presenceManager = new PresenceManager();
presenceManager.initialize();

// Check if user is online
if (presenceManager.isOnline("user123")) {
  console.log("User is online");
}

// Cleanup when done
presenceManager.cleanup();

​
Display Presence Indicator

function getPresenceIndicator(user) {
  const status = user.getStatus();
  
  if (status === "online") {
    return {
      color: "green",
      text: "Online"
    };
  }
  
  const lastActive = user.getLastActiveAt();
  const lastSeen = formatLastSeen(lastActive);
  
  return {
    color: "gray",
    text: `Last seen ${lastSeen}`
  };
}

function formatLastSeen(timestamp) {
  if (!timestamp) return "Unknown";
  
  const now = Date.now();
  const diff = now - timestamp * 1000;
  const minutes = Math.floor(diff / 60000);
  
  if (minutes < 1) return "just now";
  if (minutes < 60) return `${minutes} min ago`;
  if (minutes < 1440) return `${Math.floor(minutes / 60)} hours ago`;
  return new Date(timestamp * 1000).toLocaleDateString();
}

​
Best Practices

  • Use role-based or friends-only presence for large apps
  • subscribePresenceForAllUsers() can be resource-intensive with many users
  • Remove listeners when components unmount
  • Show green dot for online users
  • Display “Last seen” for offline users
  • Update presence indicators in real-time
  • Consider showing “typing…” instead of “online” when user is typing
  • Some users may prefer to hide their online status
  • Consider adding presence privacy settings in your app

​
Next Steps

Retrieve Users

Fetch and search users

Typing Indicators

Show when users are typing

User Management

Create and update users

Block Users

Block and unblock users