Aether Launcher

A minimal, extensible, lightning-fast Minecraft launcher.

Overview

Aether is designed with a single core principle: This launcher exists to launch Minecraft, and nothing more.

Every feature that is not essential to launching the game—like downloading mods, managing servers, or viewing logs—is implemented as an extension. By keeping the core launcher intentionally minimal, Aether remains fast, predictable, and free from bloat. Think of it as the VS Code of Minecraft launchers. You install only the features you actually want.

Features

• Blazing Fast: Cold starts in under 2 seconds with an idle memory footprint below 100MB.
• Minimalist UI: Clean, native-feeling, elegant design that gets out of your way, complete with smooth custom toast notifications.
• Snapshot Support: Effortlessly toggle between stable releases and latest snapshots when creating instances.
• Extensible Architecture: Everything from Modrinth integration to server browsers is an extension.
• Capability-Based Extensions: Extension backend code runs in a restricted Goja runtime and can only use the launcher APIs granted by its manifest permissions.
• Version Compatibility: Extensions declare a minLauncherVersion — the Gallery automatically blocks installation on incompatible launcher versions with a clear warning.

Screenshots

Sign In

Sign in with Microsoft, or use an offline username.

Home

Launch your current instance and see install progress and extension updates.

Create Instance

Pick a name, Minecraft version (with a snapshots toggle) and mod loader.

Instance Settings

Rename an instance, set memory allocation and icon, or open its folder.

Extensions Gallery

Browse official and community extensions, or install from a .aex file.

Extension Permission Prompt

Extensions ask before pinning their pages to your sidebar.

Modrinth Browser Extension

Search Modrinth for mods, modpacks, resource packs and shaders.

Installing a Mod

Choose a version and the instance to install it into.

Documentation

All project documentation is located in the docs/ directory. If you are looking to contribute, build an extension, or just understand how Aether works, start here:

• Project Philosophy & Design - The core principles guiding Aether's development.
• Architecture - Overview of the Go backend, Extension Manager, and launcher pipeline.
• API & Interoperability - Details on the extension API and permission model.
• Extensions Guide - How to build, package, and publish extensions for Aether.
  • Looking for the official extension registry? Visit the Aether-Extensions repository.
• Themes Guide - How to build and package .theme CSS/asset overwrites for Aether.
• Security & Sandboxing - Threat models, capability isolation, and review guidelines.
• UI Specifications - Layout rules, components, and empty states.
• Styleguide - Visual language, typography, colors, and animations.

Developer Tooling

The following tools are available for building Aether extensions. They are maintained outside this core launcher repository:

• Aether SDK (@aethermc/sdk) — TypeScript type definitions and helper utilities for extension development, published to npm. Install with npm install --save-dev @aethermc/sdk. Licensed under the Aether Extension API License — closed-source extensions are permitted, subject to Gallery review.
• Aether CLI (aether-cli) — Scaffold, validate, and package extensions into .aex format. Install with go install github.com/Aether-Launcher/aether-cli@latest.

Getting Started

Download the latest release for your platform from the Releases page.

Platform	File
Windows (x64)	Aether-windows-amd64-installer.exe
macOS (Apple Silicon)	Aether-macos-arm64.dmg
Linux (x64)	Aether-linux-amd64.AppImage (or .tar.gz)

Linux troubleshooting

Always run the AppImage itself, not the extracted binary:

chmod +x Aether-linux-amd64.AppImage
./Aether-linux-amd64.AppImage
# do NOT do: ./Aether-linux-amd64.AppImage --appimage-extract && ./squashfs-root/usr/bin/Aether
# (that bypasses AppRun and will always fail with libwebkit missing)

If you see libwebkit2gtk-4.1.so.0: cannot open shared object file or Unable to spawn ... WebKitNetworkProcess (No such file or directory):

# Ubuntu 22.04+ / Debian 12+ / Mint 21+
sudo apt update && sudo apt install libwebkit2gtk-4.1-0 libgtk-3-0 libayatana-appindicator3-1
# Arch Linux
sudo pacman -S webkit2gtk-4.1 gtk3 libappindicator-gtk3
sudo mkdir -p /usr/lib/x86_64-linux-gnu/webkit2gtk-4.1
sudo ln -sf /usr/lib/webkit2gtk-4.1/WebKitNetworkProcess /usr/lib/x86_64-linux-gnu/webkit2gtk-4.1/WebKitNetworkProcess 2>/dev/null || true
sudo ln -sf /usr/lib/webkit2gtk-4.1/WebKitWebProcess /usr/lib/x86_64-linux-gnu/webkit2gtk-4.1/WebKitWebProcess 2>/dev/null || true
# Fedora
sudo dnf install webkit2gtk4.1 gtk3 libappindicator-gtk3

The AppImage does not bundle WebKit itself — it uses your host's WebKit, like Chrome/Electron do.

Building from Source

If you'd like to build Aether from source, ensure you have the following installed:

• Go 1.25+
• Node.js 20+
• Wails CLI v2
• Linux only: sudo apt install libgtk-3-dev libwebkit2gtk-4.1-dev libayatana-appindicator3-dev to build (wails build -tags webkit2_41), and sudo apt install libwebkit2gtk-4.1-0 libgtk-3-0 libayatana-appindicator3-1 to run the AppImage/binary.

# Clone the repository
git clone https://github.com/Aether-Launcher/Aether.git
cd Aether
# Run in development mode (live reload)
wails dev

# Or build a production binary
wails build

License

The Aether launcher and first-party tooling are licensed under the GNU GPL v3.0-only. See LICENSE.

The Aether Extension API (SDK) is licensed separately under the Aether Extension API License. It permits closed-source extensions subject to official Gallery review, while fully preserving anyone's right to fork the launcher under GPL-3.0 or implement alternative APIs.