World's First Chat Operating System

FlockOS enables developers to build apps, bots and integrations on top of Flock, the #1 team messenger.

Apps are a first class citizen in Flock, and FlockOS allows your apps to blend seamlessly with the native Flock experience.


With FlockOS, your apps can

  • Send Messages and Attachments to Flock groups and users. For example, the GitHub app sends configurable notifications to any Flock Group. The Todo app notifies your group whenever a task is completed.
  • Configure a Bot to send directed messages to users like the Reminder bot, which sends a reminder message at a scheduled time.
  • Add an Attachment Picker to the Attachment Picker bar. For example, the Poll app adds a button to the Attachment bar that allows a user to create and send opinion polls in Flock
  • Add a Chat Tab Button to the Chat tab bar. The Todo app adds a button to the Chat tab bar, which pops up the sidebar widget and shows the various tasks of the team
  • Add Widgets to Flock desktop and mobile clients. These include the modal widget, the sidebar widget and the attachment widget. Apps such as the Poll app, Todo app and others use these widgets to provide an amazing GUI for their apps
  • Setup a Slash Command to receive commands from the user. For example, the /video slash command creates a video conference room and displays its URL in the group
  • Setup a Launcher Button. For example, the ToDo app uses the App Launcher button to display a list of todos.
  • Receive specific URLs to generate URL Previews. For example, the Google Drive app subscribes to all URLs starting with to provide a rich preview back.


The easiest way to get started with FlockOS development is to go through the tutorial on building a FlockOS app from scratch.

Further Reading

API Reference

While building your app, you can go through our API reference here: