First docs in the repo -- README.md is still the stock KMP template. Three documents plus an index, covering the parts whose behaviour is not recoverable by reading the code: where the reasoning lives in a protocol, where a failure mode is silent, or where a decision looked arbitrary and was not. marmot-membership.md is the one that earns its place. Everything about adding a member compiles, the invite reports success, and a member simply never appears -- and the reason is never in the invite code. It records that inviteMemberToChatRoom hardcodes isOneMemberInitialGroupCreation = false and that ChatRepository does not expose it, so every group invite takes the deferred-welcome path including the first, when the group is still just its creator and the commit has no audience at all. Then why that is silent rather than noisy: MarmotInboundManager refuses future-epoch messages outright, on both wire formats, with no queue and no replay, so a commit arriving before its recipient's welcome is dropped and that member never advances. EPOCH_RETENTION_WINDOW retains past epochs and does nothing for messages from ahead. Three options are set out with the per-invite correctness table, including the honest limit that the recommended one narrows the race without closing it. shared-key-derivation.md argues why the paths are not BIP32 -- no chain code exists, hardened derivation is impossible rather than unimplemented, and a FROST tweak takes the scalar as input so the chain code leaves the problem entirely. It records the x-only serialisation trap avoided by choosing the scalar directly, and states the rule that must not be broken: never reconstruct a derived key in the clear, because k = k' - t hands over the group key rather than one derived key. shared-key-ceremony.md covers the seven kinds, the three approval gates and why the coordinator's aggregations are deliberately not among them, faults as values rather than exceptions, and the transcript's idempotency-by-construction. It also writes down the invariant that produces no error when broken: pendingApproval must mirror the gates in advance, or the screen offers an approval that does nothing -- or none while the ritual sits still. Every factual claim was checked against the source rather than recalled, which turned up one correction worth having: there are two future-epoch refusals, for PrivateMessage and for Commit, so the drop covers both wire formats and not just one. Each document leads with the failure mode rather than the architecture, on the grounds that a failure is what sends somebody to docs in the first place, and each lists its known gaps -- including that none of this has run on a physical device. 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…