How Anti Delete Feature Works in WhatsApp Bot

The anti delete feature is one of the most loved features in WhatsApp bots. When someone deletes a message in a group, the bot can still show what was deleted. Many users think this is magic, but in reality, it is smart message tracking using Baileys events.

Understanding the Concept

When a message is received, Baileys gives your bot full access to the message object. If you store that message data, you can reuse it later even if the sender deletes it from WhatsApp.

Step 1: Store Incoming Messages

let store = {};

sock.ev.on('messages.upsert', ({ messages }) => {
  const msg = messages[0];
  store[msg.key.id] = msg;
});

Step 2: Detect Message Deletion

Baileys provides a protocol message event when a message is deleted.

sock.ev.on('messages.update', (updates) => {
  updates.forEach(update => {
    if(update.update?.message?.protocolMessage?.type === 0){
      const deletedId = update.key.id;
      const originalMsg = store[deletedId];
      
      if(originalMsg){
        sock.sendMessage(update.key.remoteJid, {
          text: "Deleted Message:\n" + (originalMsg.message.conversation || "Media Message")
        });
      }
    }
  });
});

Handling Media Messages

For images, videos, and stickers, you can download and save media when first received, then resend it if deleted.

Why This Works

• WhatsApp deletes messages only for users, not from your bot memory
• Your bot already saved the content
• Deletion event only notifies, it does not erase your stored data

Important Tips

• Do not store too many messages in RAM, use a database if needed
• Enable this feature mainly for groups
• Inform users about the feature to avoid privacy issues

Conclusion

The anti delete feature is simple logic with powerful impact. By storing messages and listening to deletion events, your bot can reveal deleted content easily using Baileys.