Shack(Self Hosted Action, Collaboration, and Knowledge-Base) is team messaging for organizations that care where their conversations live. Chat in channels and direct messages, share files, send voice messages, and call your colleagues by voice or video, all in one place.

Shack is used by invitation. To sign in, you need a Shack workspace from your organization: enter your Organization ID (usually your company's domain) and your work email.

YOUR DATA, YOUR CHOICE
Every organization gets its own isolated workspace: its own database, its own file storage and its own keys, shared with no one else. Run it on your own server so that you hold every key and we have no access at all, or let us host it for you.

• No advertising, no analytics and no tracking in the app
• We never sell your data or use it to train AI models
• All connections use HTTPS (TLS); the app refuses anything else
• Voice and video calls are end-to-end encrypted (DTLS-SRTP)
• Attachments can be encrypted at rest with AES-256
• Notifications carry no message content unless you turn previews on

MESSAGING
• Channels for teams and topics, direct messages and group conversations
• Threaded replies, reactions, mentions and @handles
• Share photos, videos, documents and audio files
• Record and send voice messages
• Pin, save and schedule messages
• Reminders and tasks you can assign to teammates
• Search your conversations

CALLS
• Voice and video calls, one-to-one or with a group
• Media travels directly between participants where possible, end-to-end encrypted

PRESENCE THAT RESPECTS YOUR TIME
• See who is available, away or in do-not-disturb
• Set a status such as "In a meeting" or "On vacation"
• Set your working hours: outside them you show as off the clock and notifications stay quiet

BUILT FOR WORK
• Two-step sign-in with an authenticator app
• Single sign-on with your company's identity provider (for example Google Workspace, Microsoft Entra ID or Okta)
• Administrators control members, roles, retention and security settings
• An access log for organizations with compliance needs, such as healthcare
• Export everything: your organization can take all of its data with it at any time

EVERYWHERE YOU WORK
Shack is also available for iPhone and iPad, macOS, Windows, Linux and the web, so your conversations follow you from desk to phone.

Learn more and set up a workspace for your organization at shackmessenger.com.
Privacy policy: shackmessenger.com/privacy.html