How was I launched?

The same Kotlin code can ship as a DMG, an MSIX, a Flatpak, a Snap, an AppImage, an .exe installer, or just ./gradlew run in your IDE. Each of those changes some hard rules — where you may write files, which auto-update channel to use, what the install path looks like. ExecutableRuntime lets your runtime branch on that without guesswork.

TL;DR

• ExecutableRuntime.type(): ExecutableType returns the packaging format. The Nucleus plugin sets the nucleus.executable.type system property at packaging time.
• Convenience checks: isAppX(), isFlatpak(), isDmg(), isAppImage(), isJar() (a.k.a. dev mode), etc.
• Use it to gate auto-update, file paths, store-vs-direct update strategies, sandbox-aware code.

Install

Comes with core-runtime. The aot-runtime module re-exports the same types if you only want AOT detection.

Quickstart

import dev.nucleusframework.core.runtime.ExecutableRuntime
import dev.nucleusframework.core.runtime.ExecutableType

when (ExecutableRuntime.type()) {
    ExecutableType.AppX     -> showMicrosoftStoreUpdate()
    ExecutableType.Snap     -> showSnapStoreUpdate()
    ExecutableType.Flatpak  -> showFlathubUpdate()
    ExecutableType.Pkg      -> showMacAppStoreUpdate()
    else                    -> NucleusUpdater { /* ... */ }.checkForUpdates()
}

if (ExecutableRuntime.isAppX()) {
    // Sandboxed: write to per-package state, not arbitrary HOME paths
}

How it works

The Gradle plugin writes -Dnucleus.executable.type=<kind> into the launcher's .cfg file at packaging time. The same property gets baked into native-image builds. ExecutableRuntime.type() simply reads the property — which means it is exactly as reliable as your packaging pipeline (and entirely uncoupled from filesystem heuristics like "is /snap/ in my path").

In ./gradlew run no property is set, so the runtime reports Jar — treat that as your dev-mode signal. Important consequence: features that need accurate packaging detection (like AutoLaunch.wasStartedAtLogin()) short-circuit in dev mode to avoid false positives.

Reference

ExecutableRuntime

ExecutableType

Jar, AppImage, Dmg, Pkg, Exe, Msi, AppX, Deb, Rpm, Flatpak, Snap and friends.

Notes

• The Jar variant covers ./gradlew run and other unpackaged runs — useful as a "we're in dev" signal.
• For "which version am I?" use NucleusApp.version — ExecutableRuntime only knows the shape, not the contents.
• AOT cache mode (training vs runtime) lives in a sibling module — AotRuntime.mode().