The open source, self-hostable alternative to Slack. Built for teams of all kinds — from nonprofits to startups to global companies.
Slak is a clean, fast, full-featured clone of Slack — but open, extensible, and free to host. It's built using modern tools and practices, including Docker, PostgreSQL, and a rock-solid full-stack framework.
Want to run it locally or on the cloud? No problem. Slak supports one-line deployment for both development and production — including support for Fly.io and custom domains.
Whether you're a small team or a growing organization, Slak is designed to scale. Full API support, user management, real-time messaging, and integrations coming soon.