Two events published in the same second reliably lose one of them. The receiver stores the kind:445 and produces nothing from it -- no inner event, no chat line, no error anybody sees, because MarmotGroupEvent is written before the message is decrypted and so survives while everything downstream silently does not. Observed as a FROST signing session that never started on the receiver: proposeSigning publishes the proposal and then the proposer's own nonce, the relay handed them back in the other order, and the proposal was dropped. The nonce is still sitting there filed against a session that will never exist. The same bug ate a dialect earlier, which then took out the artifact referencing it via a foreign key. MLS is specified to tolerate this. RFC 9420 says a receiver that gets generation N+1 before N keeps the intermediate keys so the older message can still be read, and quartz's SecretTree does exactly that, in a private skippedKeys map. What it does not do is persist it: exportSenderStates() returns the ratchet positions only, so saveState() drops the cache. NostrDao rebuilt the group from stored state for every inbound event, so the cache was empty every single time, and generation N arriving after N+1 failed `require(generation >= applicationGeneration)` and was swallowed. Terminal -- the key is derived from a ratchet that has moved past it, and nothing asks the sender to resend. This keeps the instance alive instead. MlsGroupCache holds one MlsGroup per room, and the inbound path goes through it, so skippedKeys survives from one message to the next. That covers the case that actually bites -- a burst arriving in one sync, decrypted one after another against the same tree -- which is what every bursty flow needs: proposeRitual sends two, addArtifact sends two, and addChapter sends one per paragraph plus one, of which only the ones arriving in ascending generation order survived. Reuse is conditional on the stored state still being exactly what the cache last wrote. Sending a message advances the sender ratchet and saves; so does adding a member. When that happens the cache rebuilds rather than carrying on from a group that has been overtaken -- which is what keeps this from being worse than no cache at all: the fallback is always the old behaviour, never a diverged ratchet. One lock per room, not one overall, because the group is mutable and decryption advances it: two events for the same room decrypted at once would corrupt the tree, and a busy room should not hold up a quiet one. **This is a mitigation, not the fix.** It does not survive a restart, and it does not survive another writer, so a long enough reorder still loses the message. The fix belongs in quartz -- carry skippedKeys through saveState/restore -- and quartz is a mavenCentral binary, not a fork, so it cannot be made here. docs/mls-skipped-keys.md has the analysis, the patch, the migration constraint on the persisted state format, and the three ways to actually land it. Not verified end to end: the proposal that exposed this cannot be recovered, since its generation is already past, so confirming the fix needs a fresh burst. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
This is a Kotlin Multiplatform project targeting Android, iOS, Desktop (JVM).
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/composeApp is for code that will be shared across your Compose Multiplatform applications. It contains several subfolders:
- commonMain is for code that’s common for all targets.
- Other folders are for Kotlin code that will be compiled for only the platform indicated in the folder name. For example, if you want to use Apple’s CoreCrypto for the iOS part of your Kotlin app, the iosMain folder would be the right place for such calls. Similarly, if you want to edit the Desktop (JVM) specific part, the jvmMain folder is the appropriate location.
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/iosApp contains iOS applications. Even if you’re sharing your UI with Compose Multiplatform, you need this entry point for your iOS app. This is also where you should add SwiftUI code for your project.
Build and Run Android Application
To build and run the development version of the Android app, use the run configuration from the run widget in your IDE’s toolbar or build it directly from the terminal:
- on macOS/Linux
./gradlew :composeApp:assembleDebug - on Windows
.\gradlew.bat :composeApp:assembleDebug
Build and Run Desktop (JVM) Application
To build and run the development version of the desktop app, use the run configuration from the run widget in your IDE’s toolbar or run it directly from the terminal:
- on macOS/Linux
./gradlew :composeApp:run - on Windows
.\gradlew.bat :composeApp:run
Build and Run iOS Application
To build and run the development version of the iOS app, use the run configuration from the run widget in your IDE’s toolbar or open the /iosApp directory in Xcode and run it from there.
Learn more about Kotlin Multiplatform…