Direct messages

Open direct message conversations with users using bot.openDM(). The adapter is automatically inferred from the user ID format.

DM behavior

DMs behave slightly differently from channel messages:

• Implicit mentions — DM messages automatically set isMention=true, so your onNewMention handler fires without the user needing to @-mention the bot. This feels natural for 1:1 conversations.
• Per-conversation threading — Each top-level DM starts a new conversation. Thread replies within a DM continue the same conversation, giving you the same per-thread isolation as channels.

Open a DM

From an Author object

The most common pattern — use the author from an incoming message:

bot.onSubscribedMessage(async (thread, message) => {
  if (message.text === "DM me") {
    const dmThread = await bot.openDM(message.author);
    await dmThread.post("Hello! This is a private message.");
  }
});

From a user ID

Pass a user ID string directly. The adapter is inferred from the ID format:

const dmThread = await bot.openDM("U1234567890"); // Slack

Check if a thread is a DM

bot.onSubscribedMessage(async (thread, message) => {
  if (thread.isDM) {
    await thread.post("This is a private conversation.");
  }
});