A small, private, end-to-end encrypted messenger. Your keys never leave your device. The relay only ever sees ciphertext.
Unsigned build — Windows may show a SmartScreen prompt; choose “More info → Run anyway”.
Messages are encrypted on your device with a Double-Ratchet protocol. Nobody in the middle — not even the relay — can read them.
Just a keypair generated on first launch. No email, no SMS, no profile to leak.
The relay stores and forwards opaque encrypted blobs. Your keys stay on your device, in your OS keychain.
Compare a safety number out-of-band to confirm who you’re actually talking to. The app makes the difference clear.
If the protocol state ever looks wrong, the app pauses and tells you — it never quietly carries on.
A tiny, deterministic core. No giant framework, no telemetry, no ads.
A two-minute walkthrough of how BlatMSG keeps your conversations private — from key generation to verifying who you're really talking to.
Yes. Every message is end-to-end encrypted with a Double Ratchet (the same family of protocol pattern used by Signal). The relay only ever transports ciphertext, and your private keys never leave your device.
No. On first launch the app generates a keypair locally. There’s no sign-up, no email, no phone number. You start a conversation by sharing a one-time invite link.
The app checks for new versions and updates itself automatically — you’ll see an “Install & restart” prompt. Updates are cryptographically signed; the app only installs builds signed with the official key.
No. BlatMSG is a small private messenger for trusted friend groups — not a commercial product and not trying to compete with Signal. It uses proven protocol patterns rather than inventing new cryptography.
Coming soon. The core is cross-platform; native Mac and Linux builds are on the way.
No. BlatMSG is a closed-source personal project. It’s built on well-known, proven protocol patterns (the Signal-style Double Ratchet via the open vodozemac library) rather than home-grown cryptography — but the app itself is proprietary.
Short version: we don't want your data, and we built BlatMSG so we can't read it.
No accounts. BlatMSG has no sign-up, no email, no phone number, and no user profiles. Your identity is a cryptographic keypair generated on your device the first time you open the app.
Your messages. Every message is end-to-end encrypted on your device. Our relay server only ever stores and forwards opaque ciphertext — it cannot read your messages, and neither can we.
Your keys. Your private keys never leave your device. They're stored locally in your operating system's secure keychain, encrypted at rest. Your message history is stored only on your own device, encrypted.
What the relay necessarily sees. To deliver messages, the relay handles routing metadata: opaque conversation identifiers, timestamps, and message sizes. It never sees message content, your contacts' names, or your keys. BlatMSG does not attempt to hide this metadata in this version.
No tracking. No analytics, no advertising, no cookies, no third-party trackers, and no selling or sharing of data. There is nothing to sell.
Updates. The app checks our update server for new versions and downloads cryptographically signed updates. These requests reveal only that a BlatMSG client checked for an update.
BlatMSG is a small, free, personal project — not a commercial service. It is provided "as is", without warranty of any kind, express or implied.
No guarantees. We don't guarantee uptime, message delivery, or that your data won't be lost. If you lose your device or your keys, your messages and identity cannot be recovered.
Your responsibility. You are responsible for your device, your keys, and how you use the app. Verify your contacts' safety numbers if identity matters to you — "encrypted" is not the same as "verified".
Acceptable use. Don't use BlatMSG to break the law or harm others.
Liability. To the maximum extent permitted by law, the author is not liable for any damages arising from the use of, or inability to use, BlatMSG.