THE USUAL WAY

Your phone is three feet from your computer.

Most apps move a recording or a note between them by sending it to a data centre on another continent and back. You make an account for the privilege, and someone else keeps a copy.

WHAT WE REMOVED

So we deleted the middle.

RECN has no backend. No server of ours holds your library, so there is no account to create, no password to lose, and nothing for us to read, sell or switch off. The only server in the picture is a RECN Node you run yourself, and even that is optional.

NO BACKEND · NO ACCOUNT · NO CLOUD LIBRARY

WHAT IS LEFT

Every device is the library.

Each device you pair holds the real thing, in two parts: the facts about your work in a database of its own, and the sound and drawings as files on its own disk. Rec on a phone, Work on a Mac, a RECN Node on a NAS: each is a whole copy. Nothing waits on a network to open, record or edit.

FACTS IN A LOCAL DATABASE · SOUND AND DRAWINGS AS LOCAL FILES

IT STARTS WITH A RECORDING

Caught, drawn and saved at the same moment.

While you play in Rec, the audio is written into its file as it arrives. Nothing is held in memory waiting for you to press stop, so a three-hour rehearsal is as safe as a ten-second idea. A note or a drawing in Work is saved the same way, as you make it. What you end up with is two things: a small fact and, often, a big file.

STREAMED TO DISK · ANY LENGTH

THE SMALL FACTS

Two edits. Two devices. Both survive.

A recording or a note is not one blob of settings. Its name, its project, its tags are separate fields, and each one carries its own clock. Rename it on the phone while the Mac files it somewhere else, and neither edit overwrites the other.

MERGED FIELD BY FIELD

WHO WINS

A clock that every device agrees on.

Every edit is stamped with the time, a counter and the device that made it. When a message arrives, the receiver moves its own clock forward. So if two devices do change the same field, there is exactly one later edit, and every device picks the same one without asking anybody.

HYBRID LOGICAL CLOCK · TIME, COUNTER, DEVICE

THE WORDS

Notes merge letter by letter.

A note is too rich for “latest edit wins”. Type in Work on the phone while someone types in the same note on the Mac, and when the devices meet both sets of words are there, in the same order on each. Drawings merge the same way, shape by shape, and the notes beside a take in Rec merge like any other note.

CRDT · NO LOCK, NO SHARED DRAFT

AFTER TIME APART

Only the gap travels.

A Mac that has been shut for a week does not download your library again. Each side says how far it has seen from every device. The other side works out exactly what is missing, announces how much is coming, and sends only that. A RECN Node is the device that was never shut, so there is always a peer to catch up from.

VERSION VECTORS · A MANIFEST, THEN THE DELTA

THE BIG SOUND

Cut into pieces. Every piece fingerprinted.

Audio does not travel as one long hopeful stream. A recording is cut into 4 MiB pieces and each piece gets its own SHA-256 fingerprint, as does the whole file. A piece is checked the moment it lands, and a bad one is fetched again on its own.

4 MIB PIECES · SHA-256 EACH

WHEN IT GOES WRONG

A dropped connection costs nothing.

The pieces already verified are written in a journal on disk, so a transfer that dies at piece three comes back at piece four, even after the app restarts. If two of your devices hold the file, they split the rest between them. Only when the whole file’s fingerprint matches does it count as a copy.

RESUMABLE · SEVERAL SOURCES AT ONCE

TWO LANES

The heartbeat never waits behind the audio.

Between every pair of devices run two lanes. One carries heartbeats, facts and acknowledgements. The other carries audio pieces and nothing else. A 2 GB session filling the pipe cannot make a healthy peer look dead.

CONTROL LANE · BULK LANE

IN THE SAME ROOM

No internet required.

On one network, a device simply says it is here. The others hear it, check its key against the devices you have paired, and start syncing. A rehearsal room with no signal is enough. The announcement carries a device name and a key, never your name.

BONJOUR · WORKS OFFLINE

THE FIRST HELLO

Pairing is two devices agreeing. Nothing else.

Nearby, one device asks and the other confirms. Across networks, one shows a code and the other scans it. A RECN Node shows its codes on a status page. The code holds a key, a way to reach it and a one-time token that expires in five minutes. No account is consulted, because there is none.

QR OR CODE · ONE-TIME TOKEN · 5 MINUTES

TRUST

Pair once. The whole set syncs.

Trust is a graph your devices keep among themselves. Pair the phone with the Mac and the Mac with the iPad, and the phone and iPad sync too. Remove a device and the mark sits on that device alone, so taking one out never disconnects the others.

A TRUST GRAPH · PER-DEVICE REMOVAL

ANYWHERE ELSE

A key is an address.

Apart, your devices cannot see each other, and both sit behind routers that refuse strangers. So a relay introduces them by key, both reach out at the same instant, each router lets its own device’s conversation through, and they are talking directly.

DIAL BY KEY · HOLE PUNCHING

WHEN A WALL STAYS SHUT

A postman, not a cloud.

Some networks will not allow a direct line. Then the relay carries the packets itself. They are sealed between your two devices before they leave, so it forwards what it cannot open and keeps nothing. The Sync screen tells you which it is: Local, Direct or Relayed.

QUIC · TLS 1.3 · KEYS ONLY ON YOUR DEVICES

THE POINT OF IT

Every copy is a whole copy.

A recording is amber until a verified copy sits on every device you have paired, and green after. There is no master and no thin client. Lose a phone and nothing is missing, because nothing lived only in the middle.

AMBER · NOT EVERYWHERE YET · GREEN · EVERYWHERE

THE WHOLE WORLD

Home, the studio, a hotel room.

The same rules hold at any distance. Direct when the networks allow, relayed when they do not, and never through a server that holds your work. If you would rather nothing left the building, one switch keeps everything on the local network.

ONLY ON MY LOCAL NETWORK · OR ANYWHERE

THE IDEA

A lattice, not a cloud.

Add a device and the lattice grows by one: a phone with Rec, a laptop with Work, a Node on the shelf. No device is in charge, and none of them is ours. Your work lives where you are.