Facebook launched chat bots on Messenger in 2016 which has since attracted over 10,000 developers. Chat bots on Messenger allow users to message bots similarly to messaging other users, and bots can send text, images, and structured messages with buttons or templates. The approval process for bots is strict, requiring documentation of how the bot connects and behaves as well as adhering to guidelines about user consent and privacy. Common reasons for bot rejection include incomplete documentation, unexpected behavior, and high block rates from users.