Unreal Launcher

A lightweight Electron desktop app for discovering, launching, and managing Unreal Engine installations and projects — no Epic Games Launcher required.

Website

What It Does

Unreal Launcher is a full replacement for the Epic Games Launcher for day-to-day Unreal Engine development. It auto-scans your drives for installed engines and .uproject files, lets you launch them with one click, browses your Fab marketplace assets, and stays completely out of your way. No bloat, no login, no waiting.

Version: 2.0.1
Stack: TypeScript · React 19 · Electron 39 · Vite 7 · Tailwind CSS 4 · Zustand · Framer Motion · Rust (napi-rs)

Core Features

Engine Management (7 features)

#	Feature	Description
1	Auto-Scan Engines	Discovers UE4 & UE5 installations across common paths (`C:\Program Files\Epic Games`, `D:\Unreal`, etc.)
2	Registry Discovery	Reads Windows registry to find Epic-installed engines automatically
3	Manual Engine Add	Browse and validate any custom engine folder via file dialog
4	One-Click Launch	Start any engine version instantly
5	Engine Size Calculation	Background worker calculates full folder size without blocking the UI
6	Marketplace Plugin Browser	Lists all installed marketplace plugins per engine version
7	Engine Deletion	Remove engines from the list (does not delete files)

Project Management (12 features)

#	Feature	Description
1	Auto-Scan Projects	Recursively finds all `.uproject` files across your drives
2	Batch Import	Add up to 20 projects at once from a single folder selection
3	One-Click Launch	Open any project in its matching engine editor
4	Game Mode Launch	Launch project directly in `-game` mode
5	List & Grid View	Toggle between flat list and thumbnail grid; preference is persisted
6	Favorites Tab	Pin projects with a star; dedicated Favorites tab
7	Recent Tab	Projects sorted by actual last-opened timestamp
8	Search / Filter	Real-time name search across all projects
9	Project Size Calculation	Per-project or batch background size calculation
10	Log Viewer	Tail the latest `.log` file from `Saved/Logs/` directly in the app
11	Git Integration	Detect git status (branch, remote URL), initialize a new repo with a UE-ready `.gitignore`
12	Open in Explorer	Jump to any project folder in Windows Explorer

Fab Marketplace Browser (4 features)

#	Feature	Description
1	Auto-Detect Fab Cache	Finds Epic/Fab vault cache in common `%APPDATA%` and `%LOCALAPPDATA%` paths
2	Custom Folder	Point to any custom Fab download directory
3	Asset Scanning	Reads manifests and `.uplugin`/`.uproject` files to extract name, version, description, icon, compatible UE versions
4	Asset Type Detection	Classifies each asset as Plugin, Content Pack, or Project

UE Tracer (5 features)

#	Feature	Description
1	Background Tracking	Rust executable (`unreal_launcher_tracer.exe`) runs silently and records engine/project usage
2	Data Merging	Tracer data is merged with saved data on every scan, enriching `lastOpenedAt` timestamps
3	Windows Startup	Optionally register tracer in the Windows registry `Run` key to auto-start with Windows
4	Process Detection	Check if the tracer is currently running via tasklist
5	Data Directory Access	View and manage the tracer data folder from Settings

Appearance & Theming (7 features)

#	Feature	Description
1	Built-in Themes	Dark, Darker, Midnight Blue, Warm Dark presets
2	Per-Token Color Overrides	Override any individual color token in the theme
3	Saveable Profiles	Save, rename, apply, and delete custom theme combinations
4	Font Customization	Choose font family and font size for the entire UI
5	Border Radius Control	Slider syncs border radius across all cards and UI elements
6	UI Scale	Adjust the overall UI scale factor
7	Full Reset	One-click reset all appearance customizations to defaults

System & UX (9 features)

#	Feature	Description
1	Auto-Updates	GitHub Releases-based updates via `electron-updater` with download & install flow
2	Version Check	Manual GitHub version check against latest release
3	Single Instance Lock	Second launch focuses the existing window instead of opening a duplicate
4	Splash Screen	Animated loading screen on startup
5	Resizable Sidebar	Drag handle to resize or fully collapse the sidebar
6	Stacking Toasts	Real-time feedback notifications — auto-dismiss after 4s, max 5 visible, colored accent bar
7	Error Boundary	Recoverable crash screen instead of a blank white window
8	Auto-Close on Launch	Optionally close the app automatically when launching an engine or project
9	Discord Feedback	Send bug reports or feedback directly to Discord via webhook (with file attachments)

Feature Count Summary

Category	Features
Engine Management	7
Project Management	12
Fab Marketplace Browser	4
UE Tracer	5
Appearance & Theming	7
System & UX	9
Total	44

How the App Works

Architecture Overview

┌─────────────────────────────────────────────────────────────┐
│                        Renderer Process                      │
│  React 19 + TypeScript + Tailwind CSS + Zustand             │
│  Pages: Engines · Projects · Settings · About               │
│  Components: Cards · Toolbars · Dialogs · Toasts            │
└────────────────────────┬────────────────────────────────────┘
                         │  contextBridge (IPC)
┌────────────────────────▼────────────────────────────────────┐
│                        Main Process                          │
│  Electron 39 + Node.js                                      │
│  IPC Handlers: engines · projects · fab · tracer · misc     │
│  Store: engines.json · projects.json · settings.json        │
│  Worker Threads: scan · size calculation                     │
└──────────┬──────────────────────────┬───────────────────────┘
           │                          │
┌──────────▼──────────┐   ┌──────────▼──────────────────────┐
│   Rust N-API Module │   │   Rust Tracer Executable         │
│   native/dist/*.node│   │   resources/unreal_launcher_     │
│   - scan_engines    │   │   tracer.exe                     │
│   - find_uproject   │   │   - Tracks engine/project usage  │
│   - get_folder_size │   │   - Writes to Tracer/*.json      │
│   - git_status      │   │   - Runs detached in background  │
└─────────────────────┘   └──────────────────────────────────┘

Startup Flow

App launches → single instance lock acquired
Chromium memory optimizations applied (V8 heap cap, disabled background networking)
local-asset:// custom protocol registered (serves local files to renderer)
Main window created with custom frameless titlebar
IPC handlers registered across 7 modules
Saved data loaded from %APPDATA%/Unreal Launcher/save/
Tracer data merged if tracerMergeEnabled is set
Renderer loads → splash screen shown → React app bootstraps
Default route navigates to Engines page

Scanning Flow

When you click Scan for engines or projects:

Main process spawns a Worker Thread (off the main thread)
Worker loads the Rust N-API native module
Native module performs fast filesystem traversal
Results returned to main process via worker.once('message')
Tracer data merged into results
Saved to engines.json / projects.json
Renderer receives the array and updates the UI

Size Calculation Flow

Size calculation runs entirely in the background:

Worker thread spawned per engine/project (or batch for all projects)
Rust get_folder_size() walks the directory tree (skips .git, node_modules)
Results pushed back to renderer via onSizeCalculated IPC event
Cards update in-place without re-rendering the full list

Data Persistence

All data lives in Electron's userData directory:

%APPDATA%\Unreal Launcher\
├── save\
│   ├── engines.json       ← saved engine list
│   ├── projects.json      ← saved project list
│   └── settings.json      ← app settings + fab path
└── Tracer\
    ├── engines.json       ← tracer-collected engine data
    └── projects.json      ← tracer-collected project data

On each scan, tracer data is merged with saved data. Tracer provides lastOpenedAt timestamps; saved data takes precedence for all other fields.

Tech Stack

Frontend

Library	Version	Purpose
React	19	UI framework
TypeScript	5.9	Type safety
Tailwind CSS	4	Styling
Zustand	5	State management (navigation)
Framer Motion	12	Animations
Lucide React	1.8	Icons
React Router	7	Page routing
React Window	2	Virtualized lists (large project sets)

Backend (Main Process)

Library	Version	Purpose
Electron	39	Desktop shell
Node.js	18+	Runtime
electron-updater	6.8	Auto-updates
regedit	5.1	Windows registry access

Build Tools

Tool	Version	Purpose
Vite	7	Bundler
electron-vite	5	Electron + Vite integration
electron-builder	26	Packaging & distribution
Prettier	3	Code formatting
ESLint	9	Linting

Native (Rust)

Crate	Purpose
napi / napi-derive	N-API bindings for Node.js
serde / serde_json	JSON serialization

IPC Handler Reference

The main process exposes the following IPC channels to the renderer:

Engines

Channel	Description
`scan-engines`	Scan filesystem + registry + merge tracer data
`select-engine-folder`	Open dialog, validate, add engine
`launch-engine`	Spawn engine executable
`delete-engine`	Remove from store
`calculate-engine-size`	Background folder size
`scan-marketplace-plugins`	List plugins in `Engine/Plugins/Marketplace`

Projects

Channel	Description
`scan-projects`	Find `.uproject` files + merge tracer data
`select-project-folder`	Open dialog, batch import (max 20)
`launch-project`	Open in editor
`launch-project-game`	Launch in `-game` mode
`open-directory`	Open folder in Explorer
`delete-project`	Remove from store
`calculate-project-size`	Background folder size
`calculate-all-project-sizes`	Batch size calculation with push events

Project Tools

Channel	Description
`project-read-log`	Tail latest `.log` file (64KB chunks)
`project-git-status`	Read branch, remote URL from `.git/`
`project-git-init`	`git init` + create UE `.gitignore`

Fab Marketplace

Channel	Description
`fab-get-default-path`	Find first existing Fab cache path
`fab-select-folder`	Open dialog for custom Fab folder
`fab-scan-folder`	Scan folder, extract asset metadata
`fab-save-path`	Persist custom path to settings
`fab-load-path`	Load saved Fab path

Tracer

Channel	Description
`tracer-get-startup`	Check Windows registry Run key
`tracer-set-startup`	Enable/disable + registry sync + spawn
`tracer-is-running`	Check via tasklist
`tracer-get-data-dir`	Return tracer data directory
`tracer-get-merge`	Get merge-on-scan setting
`tracer-set-merge`	Set merge-on-scan setting
`engines-get-registry`	Get registry scan setting
`engines-set-registry`	Set registry scan setting

Updates

Channel	Description
`check-for-updates`	Trigger electron-updater check
`download-update`	Download pending update
`install-update`	Quit and install
`get-app-version`	Return current version string
`check-github-version`	Compare against latest GitHub release

Misc

Channel	Description
`window-minimize`	Minimize window
`window-maximize`	Maximize / restore window
`window-close`	Quit app
`window-is-maximized`	Check window state
`open-external`	Open HTTPS URL in browser
`send-discord-webhook`	Proxy webhook with multipart support
`get-native-status`	Check if Rust module loaded
`clear-app-data`	Wipe engines, projects, settings
`clear-tracer-data`	Wipe tracer data

Project Structure

UnrealLauncher/
├── native/                    # Rust N-API native module
│   ├── src/lib.rs             # scan_engines, find_uproject, get_folder_size, git_status
│   ├── Cargo.toml
│   └── dist/                  # Compiled .node binary
├── resources/                 # Packaged assets
│   ├── icon.ico / icon.png
│   └── unreal_launcher_tracer.exe
├── src/
│   ├── main/                  # Electron main process
│   │   ├── index.ts           # Entry, protocol, single instance, memory opts
│   │   ├── ipcHandlers.ts     # Registers all IPC modules
│   │   ├── store.ts           # Data persistence (engines/projects/settings)
│   │   ├── storeTracerMerge.ts
│   │   ├── updater.ts         # electron-updater setup
│   │   ├── utils.ts           # Shared utilities
│   │   ├── window.ts          # BrowserWindow creation & management
│   │   ├── types.ts           # Shared TypeScript types
│   │   ├── scanWorker.ts      # Worker thread entry point
│   │   ├── ipc/
│   │   │   ├── engines.ts     # Engine IPC handlers
│   │   │   ├── projects.ts    # Project IPC handlers
│   │   │   ├── projectTools.ts# Log viewer, git IPC handlers
│   │   │   ├── fab.ts         # Fab marketplace IPC handlers
│   │   │   ├── fabScanner.ts  # Fab asset scanning logic
│   │   │   ├── tracer.ts      # Tracer IPC handlers
│   │   │   ├── updates.ts     # Update IPC handlers
│   │   │   ├── misc.ts        # Window, external links, discord
│   │   │   ├── workers.ts     # Worker thread pool
│   │   │   └── scanWorkers.ts # Worker scripts (engine/project scan)
│   │   └── utils/
│   │       ├── engines.ts     # Engine validation, gradient gen, registry
│   │       ├── folderOps.ts   # Folder utilities
│   │       ├── native.ts      # Rust module loader (lazy, with JS fallback)
│   │       └── projects.ts    # Project utilities
│   ├── preload/
│   │   ├── index.ts           # contextBridge — exposes electronAPI to renderer
│   │   └── index.d.ts         # Type definitions for window.electronAPI
│   └── renderer/
│       └── src/
│           ├── App.tsx         # Router setup (lazy-loaded pages)
│           ├── main.tsx        # React entry point
│           ├── pages/
│           │   ├── EnginesPage.tsx
│           │   ├── ProjectsPage.tsx
│           │   ├── SettingsPage.tsx
│           │   └── AboutPage.tsx
│           ├── components/
│           │   ├── engines/    # EngineCard, FabTab, InstalledPluginsTab, ...
│           │   ├── projects/   # ProjectCard, ProjectCardGrid, ProjectLogDialog, ...
│           │   ├── settings/   # AppearanceSection, TracerSection, DataSection, ...
│           │   ├── layout/     # PageWrapper, sidebar
│           │   └── ui/         # ErrorBoundary, ToastContext, DropdownPortal
│           ├── hooks/
│           │   ├── useEngineActions.ts
│           │   ├── useProjectActions.ts
│           │   ├── useProjectFavorites.ts
│           │   ├── useProjectFilters.ts
│           │   ├── useGitStatus.ts
│           │   ├── useTracerSettings.ts
│           │   └── useUpdateCheck.ts
│           ├── store/          # Zustand stores
│           └── utils/          # ThemeContext, settings helpers, theme utils
├── electron.vite.config.ts
├── electron-builder.yml
├── package.json
└── BUILD.md

Quick Start

Prerequisites

Node.js 18+
Rust toolchain (for native modules & tracer)
npm

Setup

git clone https://github.com/NeelFrostrain/UnrealLauncher.git
cd UnrealLauncher
npm install

Development

npm run dev

Preview production build

npm run start

Building

# Full production build (tracer + app)
npm run build

# Platform packages
npm run build:win    # Windows installer (.exe)
npm run build:mac    # macOS (.dmg)
npm run build:linux  # Linux (AppImage/DEB)

# Unpacked (no installer, useful for testing)
npm run build:unpack

See BUILD.md for the full build guide including native modules and the Rust tracer.

Scripts

Command	Description
`npm run dev`	Start in development mode
`npm run start`	Preview production build
`npm run build`	Build for current platform
`npm run build:win`	Windows installer
`npm run build:mac`	macOS package
`npm run build:linux`	Linux package
`npm run build:native`	Build Rust N-API native module
`npm run build:tracer`	Build Rust tracer executable
`npm run typecheck`	TypeScript type checking
`npm run lint`	Run ESLint
`npm run format`	Format with Prettier
`npm run clean`	Remove build artifacts

Distribution

Platform	Format	Architecture
Windows	NSIS installer `.exe`	x64
Windows	Unpacked `dir`	x64
macOS	`.dmg`	x64, arm64
Linux	AppImage	x64
Linux	`.deb`	x64

Published to GitHub Releases at: NeelFrostrain/UnrealLauncher

Contributing

See CONTRIBUTING.md for the full guide.

Fork the repo
Create a branch: git checkout -b feature/your-feature
Run npm run typecheck && npm run lint before committing
Open a pull request

License

This project uses a proprietary license. You may download and run the compiled binary for personal use, but you may not copy, modify, redistribute, or use the source code in your own projects. See LICENSE for full terms.

Support

Made by Neel Frostrain

Name		Name	Last commit message	Last commit date
Latest commit History 161 Commits
build		build
docs		docs
native		native
resources		resources
src		src
tracer		tracer
.editorconfig		.editorconfig
.env.example		.env.example
.gitignore		.gitignore
.nvmrc		.nvmrc
.prettierignore		.prettierignore
.prettierrc.yaml		.prettierrc.yaml
BUILD.md		BUILD.md
BUILD_INSTRUCTIONS.md		BUILD_INSTRUCTIONS.md
CHANGELOG.md		CHANGELOG.md
CODE_OF_CONDUCT.md		CODE_OF_CONDUCT.md
CONTRIBUTING.md		CONTRIBUTING.md
DONATE.md		DONATE.md
LICENSE		LICENSE
README.md		README.md
SECURITY.md		SECURITY.md
build-admin.ps1		build-admin.ps1
build-installer.bat		build-installer.bat
build-installer.ps1		build-installer.ps1
build-linux.sh		build-linux.sh
dev-app-update.yml		dev-app-update.yml
electron-builder.yml		electron-builder.yml
electron.vite.config.ts		electron.vite.config.ts
eslint.config.mjs		eslint.config.mjs
package-lock.json		package-lock.json
package.json		package.json
tsconfig.json		tsconfig.json
tsconfig.node.json		tsconfig.node.json
tsconfig.web.json		tsconfig.web.json

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Unreal Launcher

What It Does

Core Features

Engine Management (7 features)

Project Management (12 features)

Fab Marketplace Browser (4 features)

UE Tracer (5 features)

Appearance & Theming (7 features)

System & UX (9 features)

Feature Count Summary

How the App Works

Architecture Overview

Startup Flow

Scanning Flow

Size Calculation Flow

Data Persistence

Tech Stack

Frontend

Backend (Main Process)

Build Tools

Native (Rust)

IPC Handler Reference

Engines

Projects

Project Tools

Fab Marketplace

Tracer

Updates

Misc

Project Structure

Quick Start

Prerequisites

Setup

Development

Preview production build

Building

Scripts

Distribution

Contributing

License

Support

About

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Resources

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Code of conduct

Contributing

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