> Source file last changed: 2026-10-15. Dates inside the document record when each part was written, checked or submitted.

# CHANNEL Messenger

End-to-end encrypted messaging and calls, with no contact upload. When the
other person is nearby, a message goes phone to phone over Bluetooth or Wi-Fi and touches
no server at all.

**Encrypting the message was never the hard part.** Every mainstream messenger encrypts
contents; what they keep is the record of who talked to whom, and when. CHANNEL is built
so that record mostly does not exist: there is no account to attach it to, and the nearby
case never reaches us.

**What the product promises is the direct case** (`DECISIONS.md` §J, 1 September 2026).
Phone-to-phone is the product. Multi-hop carrying between strangers is implemented and
specified, but it is unproven in the field and is **not promised to anyone**.

**There is a server, and it is a mailbox.** When the other person is not nearby, sealed mail
waits on it until their phone collects it. It cannot read anything it holds, but it is in the
path, and pretending otherwise would be the sort of claim this project exists not to make.
`THREAT-WALKTHROUGH.md` says what it does learn.

## Status

The public site carries the same status in four states, item by item, at
[channelmessenger.net](https://channelmessenger.net) — that page carries the date, it is the
one written for users, and it is more specific than this table. There is deliberately no date
here: a second dated copy of the status is the one that goes stale.

| | |
|---|---|
| **Wire protocol** (`PROTOCOL.md`, `vectors/`) | complete |
| **`mesh-core-rs`** — the one implementation of the protocol | built; its test suite green |
| **iPhone app** | built; in TestFlight, not publicly released |
| **Android app** | built; in Play internal testing, not publicly released |
| Transports — Bluetooth, local Wi-Fi, a direct Internet link over IPv6, the server mailbox | built; the cross-platform Bluetooth case still needs a retest on two real phones |
| Languages | English, Spanish, Portuguese, German, Italian. English governs |
| Group messages and group calls | built in both apps, in testing |
| Forward secrecy (Double Ratchet) | built in both apps; used between two phones whose builds both carry it, in one-to-one conversations |
| Desktop | on a Mac with Apple silicon the iPhone app runs |

Neither app is released. **CHANNEL is a paid app** — it is sold by subscription, after a
store-managed free trial, and an install whose subscription has lapsed keeps working with sending
over the Internet withdrawn. **Nothing in this repository should be written as though the app were
free**: consumer law applies either way, and the stores are the merchant of record.

## Why the protocol came before the code

Two platform implementations — iOS and Android — drift apart unless something
pins them. `vectors/` is that something: fixed inputs to expected bytes, generated by
`vectors/generate.py` and never transcribed by hand. A second implementation can prove
conformance without a radio.

Two examples of that paying off, both real:

- The worked AAD example in `PROTOCOL.md` §3.3 was hand-written and wrong twice. Computing
  it caught both errors.
- `vectors/04-route-cost.json` does not merely check the weakest-link rule, it **discriminates**:
  an implementation that picks the strongest first hop chooses the wrong route and fails.

## What this deliberately does not do

No accounts, no phone number required, no telemetry about you (the one exception is a daily count of AI calls from a Mac that lets an AI use a profile, linked to nobody), no address-book upload, no moderation
capability, and no claim of anonymity against a global observer. Each of these is a decision
with reasoning in `DECISIONS.md`, not an omission.

Two entries on that list used to read *no server* and *no remote push*, and both were wrong by
September 2026. There is a server, and it is described above. There is remote push, because a
phone that never wakes never collects its mail; `docs/help/push.md` says exactly what Apple and
Google are told, which is that something is waiting — not who sent it, and not what it says.