DropOut

A deterministic Minecraft launcher for reproducible, inspectable game environments.

English | Chinese

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What Is This

DropOut is a modern, developer-grade Minecraft launcher built around one idea: a game setup should be traceable like a software project.

Most launchers focus on starting the game. DropOut also keeps the surrounding environment understandable: account state, Java runtime, game version, loader, instance directory, assets, libraries, and launch logs.

Minecraft environments are complex systems. DropOut treats them as versioned workspaces.

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Project Shape

DropOut is a desktop application with three active surfaces:

Surface	Path	Stack	Purpose
Desktop shell	src-tauri/	Rust, Tauri 2	Authentication, downloads, Java/version resolution, instance storage, launch orchestration
Launcher UI	packages/ui/	React 19, shadcn/ui, Vite/Rolldown, Tailwind CSS 4	Main application interface rendered inside the Tauri webview
Documentation	packages/docs/	Fumadocs, React 19, React Router 7	Bilingual product and developer documentation

The Rust core owns side effects. The React UI invokes Tauri commands and renders state. The docs package explains the product, architecture, and user workflows.

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Features

• Microsoft authentication - device-code OAuth flow, Minecraft Services login, token refresh, and persisted account state.
• Offline accounts - local accounts for testing or non-network play.
• Launch command center - one state-driven action for sign-in, repair, download, launch, stop, and failure recovery, backed by real readiness checks.
• Instance library - searchable and sortable grid/list views, progressive readiness, active-instance details, and guarded management actions.
• Instance system - isolated game directories with per-instance notes, memory and Java overrides, version, loader, mods, saves, and migration entry points.
• Automatic memory - live RAM and mod-count-aware heap sizing, protected system headroom, launch pressure checks, and per-instance overrides.
• Minecraft version management - install, verify, list, delete, and launch local versions.
• Fabric and Forge support - loader version discovery plus installer flows for modded instances.
• Java management - local Java detection, compatibility checks, Adoptium catalog lookup, downloads, resume, and cancellation.
• Concurrent downloads - asset/library queues with progress events and recovery paths.
• Configuration editor - edit launcher JSON with locally bundled Monaco, schema diagnostics, formatting, keyboard save, and discard protection.
• Release feed - GitHub release notes surfaced on the home screen.
• Game assistant - optional local or OpenAI-compatible helper for logs, crashes, and configuration questions.

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Install

Prebuilt DropOut bundles are published on the releases page. Running the launcher does not require Rust or Node.js; those are only needed for the development build.

Platform	Architecture	Download	Install
Windows 10/11	x86_64, ARM64	NSIS -setup.exe	Run the installer, then launch DropOut from the Start menu.
macOS	Apple Silicon, Intel	.dmg	Open the disk image and drag DropOut into Applications. If macOS blocks the first launch, allow it in System Settings → Privacy & Security.
Debian / Ubuntu	x86_64, ARM64	.deb	sudo dpkg -i Dropout_*.deb, then sudo apt-get install -f if dependencies are missing.
Fedora / RHEL	x86_64, ARM64	.rpm	sudo dnf install ./Dropout-*.rpm
Any glibc Linux	x86_64, ARM64	.AppImage	chmod +x Dropout_*.AppImage && ./Dropout_*.AppImage
Arch Linux	x86_64, ARM64	AUR dropout-bin	yay -S dropout-bin (or paru -S dropout-bin)
Alpine Linux 3.22	x86_64	-musl.tar.gz	Install the runtime libraries, verify the checksum, extract, and run ./dropout (see below).

Asset names embed the version and architecture, for example Dropout_0.2.0-rc.2_amd64.AppImage; pick the file matching your OS and your CPU suffix (x64/amd64/x86_64 or arm64/aarch64).

Every desktop asset has signed GitHub build provenance, so you can verify that it came from this repository's release workflow before installing:

gh attestation verify ./downloaded-asset -R HydroRoll-Team/DropOut

Alpine Linux needs the native WebKitGTK libraries before the musl archive can start:

sudo apk add ca-certificates gtk+3.0 libayatana-appindicator librsvg openssl webkit2gtk-4.1
sha256sum -c Dropout_*-musl.tar.gz.sha256 &&
tar -xzf Dropout_*-musl.tar.gz &&
cd Dropout_*-musl &&
./dropout

The musl archive is dynamically linked against Alpine packages; on glibc distributions use the AppImage, .deb, or .rpm instead. To build a bundle yourself, see Build A Desktop Release.

Step-by-step install instructions, a first-launch walkthrough, and troubleshooting live in the documentation: English · 简体中文.

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Quick Start

Prerequisites

• Rust toolchain from rustup.rs
• Node.js 22+
• pnpm 10+
• OS dependencies from the Tauri v2 prerequisites

Install Dependencies

This repository does not use pnpm-workspace.yaml. Install each JavaScript surface against the root lockfile:

pnpm install
pnpm -C packages/ui --lockfile-dir "$PWD" install
pnpm -C packages/docs --lockfile-dir "$PWD" install

pnpm install also runs the repository prepare script, which installs the local prek hooks.

Run The Desktop App

pnpm exec tauri dev

Tauri starts the React UI dev server through src-tauri/tauri.conf.json and opens the desktop window at http://localhost:1420.

Build A Desktop Release

pnpm exec tauri build

Release artifacts are produced by Tauri under the Rust target directory and configured bundle directories.

Run Package Surfaces Directly

pnpm -C packages/ui dev
pnpm -C packages/docs dev

The UI can run in a browser for layout work, but Tauri-backed flows require the desktop shell. For repeatable browser-only UI work, use the development fixtures and Playwright workflow documented in packages/ui/README.md.

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Common Commands

Task	Command
Install root tooling	pnpm install
Install UI dependencies	pnpm -C packages/ui --lockfile-dir "$PWD" install
Install docs dependencies	pnpm -C packages/docs --lockfile-dir "$PWD" install
Run desktop app	pnpm exec tauri dev
Build desktop app	pnpm exec tauri build
Run UI dev server	pnpm -C packages/ui dev
Build UI bundle	pnpm -C packages/ui build
Lint UI	pnpm -C packages/ui lint
Test UI fixtures, accessibility, and screenshots	pnpm -C packages/ui test:ui
Update reviewed UI screenshot baselines	pnpm -C packages/ui test:ui:update
Run docs site	pnpm -C packages/docs dev
Build docs site	pnpm -C packages/docs build
Check docs types/content	pnpm -C packages/docs types:check
Validate Cloudflare docs deploy	pnpm deploy:docs:dry-run
Deploy docs to Cloudflare Workers	pnpm deploy:docs
Test Rust workspace	cargo test --workspace

Deployment maintenance is documented in docs/cloudflare-deployment.md.

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Repository Layout

.
|-- assets/                 # README and project media
|-- crates/                 # Rust support crates and macros
|-- packages/
|   |-- docs/               # Fumadocs + React Router documentation site
|   `-- ui/                 # React launcher frontend
|-- scripts/                # Release and maintenance scripts
|-- src-tauri/              # Rust desktop backend and Tauri configuration
|-- Cargo.toml              # Rust workspace
|-- package.json            # Root tooling
`-- pnpm-lock.yaml          # Shared pnpm lockfile

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Architecture Notes

The command boundary is registered in src-tauri/src/main.rs. Feature modules live under src-tauri/src/core/:

• auth.rs and account_storage.rs handle Microsoft and offline account state.
• instance.rs owns isolated instance directories and metadata.
• game_version.rs, manifest.rs, and migration.rs resolve Minecraft versions and launch rules.
• fabric.rs, forge.rs, maven.rs, and downloader.rs install loaders, libraries, assets, and version files.
• java/ detects, validates, and persists compatible Java runtimes.
• modpack/, mods.rs, and content_search.rs handle modpack parsing, mod metadata, and content discovery.
• assistant.rs powers the optional troubleshooting assistant.

The UI keeps long-lived state in packages/ui/src/models/, renders routes from packages/ui/src/pages/, and shares reusable controls from packages/ui/src/components/.

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Roadmap

• Account persistence and token refresh
• Microsoft device-code login and offline login
• Java auto-detection and Adoptium download flow
• Fabric and Forge install paths
• Isolated instance/profile system
• GitHub releases integration
• Optional game assistant
• Multi-account switching
• Built-in mods manager
• Custom game directory selection
• Launcher auto-updater
• Reviewed, copy-only directory and archive migration from PCL, HMCL, MultiMC, and Prism Launcher
• Migration conflict previews, cancellation, rollback, and structured compatibility reports

The public roadmap is tracked at https://roadmap.sh/r/minecraft-launcher-dev.

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Contributing

DropOut is built for long-term maintainability. Useful contributions usually improve one of these areas:

• instance and profile workflows
• mod loader compatibility
• Java/runtime detection
• downloader reliability
• UI/UX clarity
• documentation and troubleshooting coverage

Use the standard GitHub flow: fork, branch, commit, and open a pull request against HydroRoll-Team/DropOut. UI contributors should also read the fixture and regression testing guide.

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License

Distributed under the GNU Affero General Public License v3.0. See LICENSE for details.