Teleb v1.0.0
File transfer over light
Two phones. A screen, a camera, and the gap between them. No internet, no Wi-Fi, no Bluetooth, no NFC, no pairing, no account, no server.
iOS and Android
A sender broadcasting, a receiver rebuilding. Illustration, not a live transfer.
No radio of any kind
On Android the app ships without the INTERNET permission. Not unused — absent. The operating system would refuse a connection even if the app tried to open one.
The camera is the receiver
Reading the other phone’s screen is how the file arrives. The camera runs only while a transfer screen is open, and records nothing.
About twenty centimetres
Hold both phones steady, facing each other, the code filling the frame. Glare is the usual reason a transfer stalls.
A one-way channel has no way to ask for a resend. Teleb does not need one: every frame is built so that any sufficient set rebuilds the whole file. A missed frame costs a moment, never the transfer.
- Frames sent
- 0
- Never arrived
- 0
- File
- 0%
Frames arriving. Some will not.
Both phones show the same three words.
cinderharborviolet
If they match, you are talking to the phone in front of you. If they differ, someone is in the middle — and you know before a single byte leaves. Every transfer is sealed with X25519 and XChaCha20-Poly1305, with keys that exist only on those two devices, and only for that one transfer.
An honest tool states its limits as plainly as its strengths. These are deliberate, not missing features.
Video
Refused outright. A short clip would take the better part of an hour on this channel, so Teleb says so before you start rather than twenty minutes in.
Large files
Refused outright. Above a threshold Teleb warns; above a higher one it declines. For files that big, a cable is the right tool.
Claiming delivery
There is no back-channel, so the sender cannot know whether anything arrived. Its final state reads Stopped, never Sent, and its progress is labelled an estimate — because that is what it is.
Speed
Light through a camera lens is a narrow channel. This will never feel like AirDrop. It works where AirDrop cannot.
- Key agreement
- X25519
- Encryption
- XChaCha20-Poly1305
- Coding
- LT fountain codes
- Transport
- Base45 over animated QR
- Verification
- Three-word SAS
- Permissions
- Camera · photo library optional
- Network
- None
- Platforms
- iOS · Android
- Age rating
- 4+
- Export
- ECCN 5D992.c · mass market