Group vs DM Handling

Use isGroupMsg to distinguish group traffic from direct messages, then use the complete chatId value for routing. Do not rebuild a group ID from its name or assume every incoming identifier has the same format. See the Chat ID guide for the accepted input forms.

client.onMessage(async (message) => {
  if (message.isGroupMsg) {
    console.log('Group message:', message.chatId);
    return;
  }

  console.log('Direct message:', message.chatId);
});

Allow or block groupsCopy Anchor Link

Populate the set with group IDs copied from a lookup or message event. Keeping the exact returned value avoids assumptions about the identifier suffix.

const allowedGroups = new Set([
  '447123456789-1445627445@g.us',
]);

client.onMessage(async (message) => {
  if (message.isGroupMsg && !allowedGroups.has(message.chatId)) return;
  await handleMessage(message);
});

For a blocklist, replace the condition with message.isGroupMsg && blockedGroups.has(message.chatId).

Sender and administrator rulesCopy Anchor Link

In group messages, author identifies the participant when WhatsApp provides it. Compare full contact IDs, not a bare number stripped from the ID. The current embedded Client does not expose getGroupAdmins; the generated Easy API has a getGroupAdmins method. If your workflow uses that API, compare its returned contact IDs with message.author and handle missing authors or lookup failures explicitly.

const adminsByGroup = new Map<string, Set<string>>();

client.onMessage(async (message) => {
  if (!message.isGroupMsg || !message.author) return;

  const adminIds = adminsByGroup.get(message.chatId);
  if (adminIds?.has(message.author)) return;

  await moderate(message);
});

This example uses application-owned admin data. Refresh it from the supported Easy API method when permissions change; do not treat a cached list as current membership state. See the groups guide for method availability and the event reference for group membership events.