Terms of use.

Effective: 2026-04-26.

What this is.

The terms under which you may use the Lattice app and the lattice.fyi website. Plain language. Short. Drop a note in our Matrix room if anything is unclear.

The app.

Lattice is open-source software distributed under the Mozilla Public License 2.0. The full license text governs your rights to use, copy, modify, and redistribute the source code once the repository is public (planned for v1.0); the App Store / Play Store / F-Droid distribution agreements govern your rights to install the binary on your device.

Service we provide.

We do not provide a service. There is no Lattice server, no Lattice cloud, no Lattice operations team handling your messages. The app on your device communicates peer-to-peer with other devices running the app, using the radios in those devices. We provide the source code and the website. That's it.

Because we operate no service, we make no service-level commitments. The app may have bugs. The mesh may not deliver every message. The cryptography may be broken in the future. We will fix things we can fix; we cannot promise that everything always works.

Acceptable use.

Don't use Lattice to commit crimes. Don't use it to harass people. Don't use it to send malware. We have no ability to enforce any of this — there's no central authority to enforce against — but we reserve the right to refuse to help anyone using the project for those purposes.

What we don't do.

• We don't read your messages — we can't, because of the cryptography and the no-server architecture.
• We don't moderate the mesh. We can't.
• We don't have an account-recovery process. There are no accounts.
• We don't sell your data. There is no data.
• We don't run ads. We don't intend to.

Your responsibilities.

• Back up your seed phrase. If you lose your phone and don't have your seed phrase, your Lattice identity is gone. We cannot help you. This is by design.
• Verify contacts before trusting them. Use QR-scan-in-person where you can, and the four-word phrase via a different channel where you can't. Trust on first use is our default but it is not safe in all settings.
• Use the duress-PIN feature if you may be physically coerced.
• Don't rely solely on Lattice for critical communication. It works without the internet; that's its whole point. But its delivery is best-effort, not guaranteed. If you genuinely need to reach someone, call them on a normal phone line first if that line is up.

Liability.

The MPL 2.0 includes the standard "no warranty" and "no liability" disclaimers (§§6 and 7). Those apply: we make no warranties about the app, and we are not liable for any damages arising from your use of it. Your use of Lattice is at your own risk.

This isn't legal hand-waving — it's the genuine reality of an open-source project. We will do our best to make Lattice reliable and secure, and we will publish audits and fix bugs in a timely fashion, but we cannot promise that no harm will come to you because you used it. Please make your own informed decisions about when to trust the app with critical communication.

Changes.

We may update these terms from time to time. Material changes will be announced on this page and in release notes. Continued use after a change constitutes acceptance.

Governing law.

These terms are governed by the laws of England and Wales. The MPL 2.0 itself is governed separately by the terms of that license.

Contact.

Questions: our Matrix room.