Send a broadcast message

You can send a broadcast message (1:many message or announcement) with XMTP. The recipient sees the message as a DM from the sending wallet address.

tip

If your app stores a signature to read and send XMTP messages on behalf of a user, be sure to let users know. As a best practice, your app should also provide a way for a user to delete their signature. For example disclosure text and UI patterns, see Disclose signature storage.

1. Use the bulk query canMessage method to identify the wallet addresses that are activated on the XMTP network.
2. Send the message to all of the activated wallet addresses.

For example:

const ethers = require("ethers");
const { Client } = require("@xmtp/xmtp-js");

async function main() {
  //Create a random wallet for example purposes. On the frontend you should replace it with the user's wallet (metamask, rainbow, etc)
  const wallet = ethers.Wallet.createRandom();
  //Initialize the xmtp client
  const xmtp = await Client.create(wallet);
  console.log("Broadcasting from: ", xmtp.address);

  //In this example we are going to broadcast to the GM_BOT wallet (already activated) and a random wallet (not activated)
  const GM_BOT = "0x937C0d4a6294cdfa575de17382c7076b579DC176";
  const test = ethers.Wallet.createRandom();
  const broadcasts_array = [GM_BOT, test.address];

  //Querying the activation status of the wallets
  const broadcasts_canMessage = await Client.canMessage(broadcasts_array);
  for (let i = 0; i < broadcasts_array.length; i++) {
    //Checking the activation status of each wallet
    const wallet = broadcasts_array[i];
    const canMessage = broadcasts_canMessage[i];
    console.log(wallet, canMessage);
    if (broadcasts_canMessage[i]) {
      //If activated, start
      const conversation = await xmtp.conversations.newConversation(wallet);
      // Send a message
      const sent = await conversation.send("gm");
    }
  }
}
main();