Slack Events API

The Slack Events API enables apps to respond to activities in Slack by subscribing to specific event types. Rather than polling for changes, apps receive HTTP POST payloads when subscribed events occur, such as new messages, reactions, channel changes, or user updates. The Events API offers two delivery options - a public HTTP endpoint that Slack sends event payloads to, or Socket Mode which uses WebSockets for apps that cannot expose a public URL.