Looking for a lightweight, encrypted, open source alternative to Slack or Teams that you can run on your own server? Chatto crossed that line on July 8, 2026. Here’s what it actually means in practice.
Chatto open source: what are we talking about?
Chatto is a group and team chat application, built over roughly a year by an independent developer. The project is now open source, self-hostable by anyone, and free. The source code is available on GitHub, and the official documentation lives at docs.chatto.run.
The positioning is straightforward: compete with Slack, Microsoft Teams, and Discord, while keeping full control of your data.
What Chatto offers technically
Installation is deliberately simple. Three commands via Homebrew are all it takes:
brew install chattocorp/tap/chatto
chatto init
chatto run
The binary also serves its own frontend. No external dependencies, no separate database to configure upfront. Binaries are available for Linux (x86_64 and ARM64), macOS, and Windows.
On the resource side, the project aims to be remarkably lightweight. The interface is described as highly responsive, which is a noticeable contrast to some RAM-hungry Electron-based tools.
Security and privacy by default
This is probably the project’s strongest point. Chatto encrypts all personal data and messages at rest, with per-user keys. When an account is deleted, the keys are destroyed. No federation between servers, no third-party tracking, no external analytics.
Each Chatto instance serves a single community. To host multiple spaces, you run multiple processes. Simple, predictable, auditable.
Voice and video calls included
Chatto includes voice, video, and screen sharing natively. Calls are end-to-end encrypted. Scalability depends on the infrastructure you put behind it, but the architecture doesn’t create any software-side bottleneck.
Chatto Cloud: the hosted option is coming
For those who don’t want to manage infrastructure, a Chatto Cloud offering is entering public beta soon. The business model is intentionally minimal: you pay for hosting, that’s it. No premium subscription, no advertising.
The infrastructure will be fully European and owned by European entities at launch. Announced features include:
- Automatic scaling
- Nightly backups of all data
- Zero-downtime updates
- Full portability: migrate to or from self-hosting at any time
Chatto Cloud servers are 100% compatible with self-hosted instances. No vendor lock-in.
Where does the project stand?
Chatto is currently at version 0.4. The developer considers it stable enough for production use, but notes that some features are still missing. The roadmap for version 0.5 focuses on content moderation and reporting, along with improvements to the multi-server experience.
Version 1.0.0 is expected in six to twelve months. Breaking changes are still possible between now and then. If you deploy to production, plan to follow updates closely.
Why it deserves attention in the DevOps and security ecosystem
The self-hosted communication tools market is crowded, but often disappointing. Matrix/Element remains complex to operate. Rocket.Chat has grown heavier. Mattermost keeps pushing toward its paid offerings.
Chatto bets on operational simplicity and security by default, two criteria that matter in a DevOps context or for teams sensitive to privacy. A single binary, at-rest encryption with per-user keys, no data leaving to third parties: that’s a solid starting point.
The fact that Chatto Cloud infrastructure is announced as European and sovereignty-respecting will also carry weight in certain regulatory contexts (GDPR, public sector, healthcare).
Some unknowns remain: the exact license for the source code isn’t specified in the main announcement, and the project is still young. Worth watching as it progresses toward 1.0.
Key takeaways
- Chatto is a group chat application, now open source and freely self-hostable as of July 8, 2026.
- A single binary is enough to run a complete instance with an integrated frontend, voice, video, and screen sharing.
- At-rest encryption with per-user keys and the absence of third-party tracking make it a serious choice for privacy-conscious teams.
- Chatto Cloud, with European infrastructure, will enter public beta soon for those who prefer to delegate hosting.
- The project is at version 0.4, stable according to its author, but with more changes ahead before 1.0.
If self-hosted chat or communication sovereignty interests you, feel free to discuss it or follow the blog for future coverage.
Sources
- Official Chatto open source announcement – Blog of the lead developer
- Chatto self-hosting documentation – Official documentation
- Hacker News discussion – Community thread (score 40)