Paul HittandClaude Opus 5.5
eb9b7647b3
A game lives on its start message's history row as the log alone, so it follows that row through off the record (memory only), delete, the disappearing timer and the backup. Everything else is replayed from the log with the capped engine replay. Receiving follows §6.33 rules 1 to 4: an unknown game is rebuilt from the envelope; a stale or duplicate log changes nothing; a log that disagrees, a peer adding a ply for this person's side, an illegal or malformed move, or a log over the cap marks the game out of step, which is sticky. Endings follow DESIGN items 16, 22 and 23: an ending is judged at the log its gend carries, once that log is in step; a draw offer counts only from the side that has just moved, at the receiver's whole log, and the next move lapses it; decline and cancel count only until the invitee's first move in that log; a decline for a game this phone never saw rebuilds it as the game it started, declined. Moves and endings go out announced, so the other phone wakes (item 15), and are never queued: one that reaches nobody, a contact with no device included, is taken back (item 24). The start is queued like a card. Their move notifies without a sound, "Your move: chess with Sam"; an ending says "<Game> with <name>: <result>"; a draw offer "<name> offers a draw: <Game>"; a refused offer says nothing; a snoozed chat holds them all. A game from another server, or from this account's own other device, is never a board. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Flamenet Messenger. Android
The Android app, and the two libraries under it. The product's site is at https://flamenetmessenger.com.
engine/ the protocol: X3DH, Double Ratchet, sealed sender, safety numbers,
key transparency. Plain Kotlin/JVM, no Android in it at all.
client/ the relay transport: HTTP, auth, the §8 routes.
app/ the Compose app.
interop/ the cross-engine driver; not shipped.
engine and client are deliberately plain JVM libraries. The protocol has
nothing to do with Android, and keeping it off the platform means their tests
run anywhere a JVM does, no SDK, no emulator, no device, which is also what
lets them gate in CI on Linux:
./gradlew :engine:test :client:test
The app's own unit tests need the Android SDK but still no emulator (Robolectric):
./gradlew :app:testDebugUnitTest
Where it stands
PARITY.md is the definition of done for this app, read that, not this. Every row there names the iOS file it came from so it can be re-checked rather than trusted. Headlines: messaging, groups, attachments, voice notes, stories, calls, sealed sender, key transparency and the encrypted vault are built and tested, and a cross-platform round trip against iOS is verified.
If a claim here ever disagrees with PARITY.md or with the tree, believe those, and fix this.
Why the engine came first, and is held to the vectors
An Android client needs the protocol implemented a third time, and the 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 is held to
test/vectors/protocol-v1.json in
flamenet-e2e, the same file the
other two engines are checked against, read from that repository rather than
copied here, because a copied vector file drifts and a drifting vector file
stops being a check. PublishedVectorsTest looks for it beside this checkout
and fails loudly if it cannot find it; FLAMENET_VECTORS overrides the search.
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.
Contributing and security
- CONTRIBUTING.md, building (JDK 21,
JAVA_HOMEis not optional on a Mac), the test gate, and the platform traps that cost an hour each. - PARITY.md, what iOS does, what this does, and what is left. It is the definition of done for this app.
- SECURITY.md, threat model and where to send a vulnerability report. Not an issue tracker matter: security@flamenetmessenger.com.