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Android runtime

This reference describes the Android implementation of MinecraftRuntime.

Support boundary

The Android runtime supports Vanilla Minecraft 26.2 on ARM64 and x64 devices. The device must support Vulkan 1.2 or newer.

Android x64 needs Minecraft launch, input, audio, exit, and relaunch tests on a compatible device before stable release. An emulator without Vulkan 1.2 cannot launch the game. The launcher still supports instance management.

The runtime does not support other Minecraft versions or mod loaders. The launcher hides unsupported choices on Android.

32-bit ARM and x86 remain unsupported. The pinned Java 25 release has no x86 runtime. ARM32 requires separate game, memory, and graphics compatibility work.

Runtime preparation

Trestle selects native components from the running Android process architecture, rather than the device's preferred ABI. The universal APK contains both ARM64 and x64 launcher libraries. Each process installs only its matching native game libraries.

The build packages Java 25 for Android. Trestle validates the bundled archive with SHA-256 before extraction.

The build also packages Android LWJGL, OpenAL, Zink, and native bridge components. Each component has a fixed source revision and checksum. The app does not download these runtime components during launch. Minecraft assets and libraries still use their normal verified download sources. Gradle stores the component files as app assets. Trestle does not link its launcher code to those files. The runtime verifies the ELF class, byte order, and machine type before it uses a native library. ARM64 and x64 use separate runtime and component caches.

The runtime activates a component set only after all required files exist. A partial download cannot replace a complete component set.

Game process

MinecraftGameActivity owns the game surface and Java virtual machine. It starts the virtual machine through the Android native bridge.

The launcher passes these values to the activity:

  • The Java home directory.
  • The game working directory.
  • The native-library directory.
  • JVM and game arguments.
  • The main class.
  • Environment variables.
  • A result receiver for process events.

The activity sends start, log, exit, and error events to the launcher. The launcher shows these events through LaunchEvent.

Rendering and audio

The current renderer uses Mesa Zink and Kopper. It translates desktop OpenGL calls to Vulkan.

The native component set includes the patched LWJGL bridge and OpenAL Soft. The activity loads these libraries before it starts Minecraft.

Input

The game activity supports these input sources:

  • The touch overlay for movement, camera control, inventory, combat, chat, and hotbar selection.
  • Android text input for chat and command text.
  • Hardware keyboards with GLFW key and modifier translation.
  • Mouse movement, buttons, wheel input, and pointer grab.
  • Gamepads with movement, camera, action buttons, triggers, and hotbar selection.

The activity releases held input when Android destroys the game activity.

Process errors

The activity writes JVM errors to the instance crash directory. Minecraft can also write reports to crash-reports.

If the process stops without an exit event, Trestle reads Android process-exit information. It reports native errors, JVM errors, low-memory termination, and ANR events.

Licensing

The runtime uses components from Amethyst Android 1.1.6 and Android OpenJDK builds at fixed revisions. The APK contains the Amethyst LGPL license text.

Trestle downloads Minecraft files from official endpoints. It does not redistribute Mojang files or bypass ownership checks.