This scope lets an app "View messages, activity, and files in direct messages"
This OAuth permission scope works with these Web API methods and Events API events.
im.history - Fetches history of messages and events from direct message channel.im.replies - Retrieve a thread of messages posted to a direct message conversationim_history_changed - Bulk updates were made to a DM's historymessage - A message was sent to a channelmessage.im - A message was posted in a direct message channel