Paul HittandClaude Opus 5
7719ae062e
Measured out of "Light Mode - iOS/07 Messages-Details 1" rather than eyeballed: the App Bar is 88 tall with back at x=24, title 16pt Medium over a 12pt line with a dot beside it, and Call at x=279. The Message Box is 84 tall: plus at x=16, an F3F3F3 pill from x=56, camera at x=287, more at x=335. The composer is one row now. Voice recording was a chip hanging underneath it - the last thing on the screen that did not belong to that row - and the mic is an icon in the row, with the permission plumbing hoisted to where it is used. Send appears only when there is something to send; at rest the row is the kit's. iOS tab bar drops its labels, matching the kit's "Bottom Bar/Without Label" and Android. Titles survive as accessibility names - dropping text from the screen must not drop it from VoiceOver. PresenceDot was still an olive, a mustard and a rust: the previous brand's palette, left behind when the accent changed. Now teal, blue and pink from the kit. Two things the kit draws that this deliberately does not: a video-call button and an emoji key. Neither CallManager has any video path at all, and there is no emoji picker to open - the system keyboard already carries one. A mockup can draw a feature; the app cannot draw one it does not have, and this codebase has already shipped one dead call button once. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Flamenet Messenger — Android
Nothing here is an app yet. This is the engine, and it is deliberately first.
An Android client needs the protocol implemented a third time. That third
implementation is the one that finds the places where the specification says
less than the two existing engines quietly agreed on — but only if it is
written against the spec and the published vectors rather than against a
reading of our own Swift and JavaScript. So the engine comes first, it is a
plain Kotlin/JVM library with no Android in it at all, and it is held to
engine/test/vectors/protocol-v1.json — the same file the other two engines
are checked against, read from that one location rather than copied here.
./gradlew :engine:test
No Android SDK, no emulator, no device. It runs anywhere a JVM does, which is also what lets it run in CI on Linux.
What the engine covers today
| Area | Spec | State |
|---|---|---|
| Safety numbers | §7 | Done — fingerprints and conversation ordering match the published vectors |
| Key transparency verification | §19 | Done — RFC 6962 leaf/node hashing, unbalanced split, bottom-up audit paths |
| Byte helpers | — | Unsigned comparison, constant-time equality |
What it does not cover
Listed rather than left to be discovered, because a table of green ticks with the hard parts quietly missing is worse than no table:
| Area | Spec | State |
|---|---|---|
| X25519 / Ed25519 | §3 | Not started — needs a provider that works on both JVM and Android |
| X3DH key agreement | §4 | Not started |
| Double Ratchet | §6 | Not started |
| Sealed sender | §12 | Not started |
| ML-KEM-768 hybrid | §11 | Not started |
| ML-DSA-65 identities | §20 | Not started |
| Relay client | §8 | Not started |
| The app itself | — | Not started |
Until those exist, Android is honestly marked "not started" on the website, and a conversation gets the protocol's guarantees only when both ends are iOS.
Why the vectors matter more than the code
Two implementations that agree may both be wrong in the same way, especially when one was written while reading the other. The audit-path ordering in §19 is the worked example: a top-down reading of a bottom-up path produces the correct root for every left-spine index, so it passes any test that only checks index 0. The vector file pins a right-descending index for that reason, and the Kotlin tests assert both that the published path verifies and that the same path reversed does not.
If this engine ever disagrees with the file, the interesting question is which of the three is wrong — not this one by default.