amethyst: Skill for Claude Code

Gradle Expert

Build system expertise for AmethystMultiplatform's 10-module KMP architecture (amethyst, benchmark, quartz, geode, commons, quic, nestsClient, desktopApp, cli, quic-interop — see settings.gradle.kts). Focus: practical troubleshooting, dependency resolution, and project-specific optimizations.

Build Architecture Mental Model

The core app stack is 4 layers (the other modules hang off it: cli and geode are JVM apps over commons/quartz, nestsClient sits on quic, benchmark and quic-interop are test harnesses):

┌─────────────┬─────────────┐
│ :amethyst   │ :desktopApp │  ← Platform apps (navigation, layouts)
│ (Android)   │    (JVM)    │
└──────┬──────┴──────┬──────┘
       │             │
       └──────┬──────┘
              ▼
      ┌─────────────┐
      │  :commons   │           ← Shared UI (KMP with jvmAndroid)
      │  (KMP UI)   │
      └──────┬──────┘
             ▼
      ┌─────────────┐
      │  :quartz    │           ← Core library (KMP: Android/JVM/iOS)
      │(KMP Library)│
      └─────────────┘

Key insight: Dependencies flow DOWN. Lower modules never depend on upper modules. This enables code sharing without circular dependencies.

The jvmAndroid pattern: Unique to this project. A custom source set between commonMain and {androidMain, jvmMain} for JVM-specific code shared by Android and Desktop. Not standard KMP, but critical for this architecture.

Version Catalog Philosophy

All dependencies centralized in gradle/libs.versions.toml. Think "single source of truth."

Pattern:

[versions]
kotlin = "2.3.0"

[libraries]
okhttp = { group = "com.squareup.okhttp3", name = "okhttp", version.ref = "okhttp" }

[plugins]
kotlinMultiplatform = { id = "org.jetbrains.kotlin.multiplatform", version.ref = "kotlin" }

Usage:

dependencies {
    implementation(libs.okhttp)  // Type-safe, IDE-autocompleted
}

Critical alignments:

• Kotlin ecosystem: All Kotlin plugins MUST share same version
• Compose ecosystem: Compose Multiplatform version → Kotlin version (check compatibility matrix)
• secp256k1 variants: All three variants (common, jni-android, jni-jvm) MUST share same version