This app event notifies your app when a user has entered into the App Home space—that's the place where a user exchanges DMs with your app.
Your Slack app must have a bot user configured and installed to use this event.
Use the app_home_opened event to begin a friendly onboarding flow from your app, a whimsical welcome message, or a deep-dive into a detailed dialog. Since the app_home_opened event is only sent to your app when a user has already clicked on your app, you can rest assured that your attentions are welcome.
Note: app_home_opened events are sent each time a user enters into the App Home space. Verify that this is the first interaction between a user and your app before triggering your onboarding flow.
app_home_opened events are just like other message events sent over the Events API, but their type indicates app_home_opened.