Unwritten
Nothing stored, nothing left behind, nothing resent
End-to-end encrypted messages, files and voice calls. The server cannot read them and does not keep them, and your identity lives only on your own device.
What it does
Only what it actually does.
Messages live in memory
Messages and files travel encrypted between the two devices. Lock or close the app and no conversation is left on the device. If the other person is offline the message is not delivered rather than kept somewhere to wait.
You hold your identity
Your identity is a key that exists only on your device, protected by your passphrase, bound to the device's security chip or locked with a FIDO2 security key such as a YubiKey.
Encrypted calls, disguised voice
One-to-one and group voice calls are end-to-end encrypted too. With the voice changer on, what the other side hears and records is not your real voice.
Circles
Small groups, encrypted end to end between members, with group calls.
Contact only by consent
Add people by username or by scanning their code; both sides agree before anything is exchanged. Compare safety numbers, block anyone.
Leave whenever you want
Delete account removes your username from the server and then wipes the device. Emergency destroy works offline and wipes the device at once.
The app
On Android and Windows.
Unwritten Capsule
A hardware key that keeps your identity key in its own secure chip. It connects to your phone or computer over USB-C or Bluetooth, and pairing takes a press of its button.
What the server sees
A privacy product should say this plainly.
Never on our servers
- The content of messages, files and calls
- Your identity key and your passphrase
- Your contact list
- Who is behind an address: messages travel on rotating addresses derived between the two of you, not linked to your identity or username
What it necessarily sees
- The IP address you connect from, when, and how much data passes; from that, whoever runs the servers can tell which connections exchange traffic
- The username you chose and your public key, so that others can find you
- Whether your licence is valid
Pricing
Yearly
US$24,000
US$20,000
per account, per year
Save US$4,000 · 2 months free
Works out to about US$1,667 a month
Monthly
US$2,000
per account, per month
US$24,000 a year
To buy, or with any question, you are welcome to contact us.
Download
Test build v16 · 2026-10-16
Windows15.5 MB
Windows 10 or later, 64-bit.
- Unzip and run lingjie.exe in the folder.
- It is not signed yet, so SmartScreen will stop it: choose More info, then Run anyway.
Android80.7 MB
Android 10 or later.
- Open the downloaded APK and allow installing from your browser when asked.
- A Google Play version will follow at release.
Check the SHA-256 after downloading to be sure the file was not altered. All of them are also in SHA256SUMS.txt.
Delete your account
You can delete your account at any time.
In the app
Settings → Danger zone → Delete account. The server removes your username, your seat on the licence and any contact requests still waiting for you; then the identity, contacts and circles on the device are destroyed.
There are no messages, files or calls of yours on the servers to delete: they were never kept. The licence itself stays as a record of the purchase; after the account is deleted it is linked to no username.