Paul HittandClaude Opus 5
be03175996
Android 0.7 crashed on answering a call and it took somebody noticing. There was nothing in the tree that read exit reasons, so a crash was something a person had to report in prose. ApplicationExitInfo is Android's own record: no library, no network call, no identifier, the same shape of answer MetricKit is on the iPhone. It is stricter here in one way. MetricKit delivers a payload once and it is gone, so that side keeps a file; Android hands back the same list every time it is asked, so the system is the store and this app writes nothing at all. Ordinary exits are dropped rather than greyed out. A list of "you swiped the app away" buries the one line somebody came to the screen for. REASON_SIGNALED goes with them: in practice it is the system or a debugger sending SIGKILL, and a real native crash arrives as REASON_CRASH_NATIVE. setProcessStateSummary at launch stamps the running build into the 128 bytes Android returns with an exit record, so a report can say which build died. By the time anybody reads one the app has usually been updated. Saved through the system file picker, not a share sheet. There is no FileProvider here and a trace is too big to travel as intent text: past a few hundred kilobytes that throws, which would fail on exactly the largest and most useful report. Saving is also how a history backup leaves this app. The dialog's layout came from the test. With everything in one scrolling column the address and the save button sat below the explanation and off the bottom of a small screen, so the two things somebody opened it to do were the two they had to go looking for. Only the trace scrolls now. Co-Authored-By: Claude Opus 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.