Chatto, a self-hostable and extensible team group chat application, has officially transitioned to an open-source model under the GNU Affero General Public License v3.0 (AGPL-3.0).
Hendrik Mans has open-sourced Chatto, a modular, self-hostable group chat application designed to be a lightweight and familiar alternative to platforms like Slack, Microsoft Teams, and Discord. Built with a focus on ease of deployment, low system requirements, and data privacy, the platform is now available on GitHub. It features both a Client API (using WebSockets for real-time updates) and a server-side Extension API, allowing developers to create custom integrations or replace core components such as search. Chatto intentionally avoids federation to prioritize strict data containment and compliance for single-instance setups.
Self-hostable communication platforms are seeing a resurgence as companies seek to cut SaaS costs and retain absolute ownership of their data, but the success of Chatto will depend on how quickly it can mature from its current alpha state given that it is currently not accepting outside contributions.
* Extensibility is a core strength, with modular Client and Extension APIs allowing teams to customize search modules and build custom bots or clients.
* The choice of the copyleft AGPL-3.0 license protects the developer's IP while allowing self-hosting, though it may deter some enterprise adopters who are wary of copyleft requirements.
* Not offering federation sets it apart from Matrix or Mastodon, keeping the focus strictly on single-instance compliance and safety, which is highly appealing for corporate intranets.
* Since the repository currently lists a restriction on external contributions, it remains primarily a solo-developed project, which may slow down its roadmap compared to fully collaborative open-source alternatives.
DISCOVERED
1h ago
2026-07-08
PUBLISHED
2h ago
2026-07-08
RELEVANCE
AUTHOR
speckx