ky3 Launcher

A modern third-party launcher for Genshin Impact, built with WinUI 3

English | 简体中文

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Preview

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Localization

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Features

Feature	Description
Game launching	Custom launch arguments, command-line injection, window mode selection, fast multi-account switching, automatic DLL plugin loading
Character planning	Level ascension material calculator, talent upgrade planning, resin cost estimation, daily/weekly boss reward statistics
Weapon & character wiki	Browse all characters/weapons with stats, filtering and sorting, constellation & refinement data, recommended artifact builds
Quest collection	Archon & Story Quest overview, quest reward statistics, filter by region
Achievement tracking	Local achievement state reading powered by Yae, categorized browsing and search
Auto check-in	Daily automatic check-in for miHoYo BBS / HoYoLab, batch execution across multiple accounts, result notifications
Incremental updates	File-level delta patching (BsDiff), resumable downloads, local verification — no need to re-download the full package
Plugin management	Hot loading/unloading of DLL mods, version management, one-click enable/disable
Real-Time Notes	Live view of resin / expeditions / Realm Currency / Parametric Transformer, synced per account
Wish analysis	Gacha record import, pity counter, drop rate statistics, history visualization

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Tech Stack

Layer	Technology	Description
Framework	.NET 10 / WinUI 3	Windows App SDK, modern desktop UI framework
Language	C# 14 (preview)	Latest language features, Source Generators
Architecture	MVVM	CommunityToolkit.Mvvm, ObservableProperty, WeakReferenceMessenger
Database	SQLite	Entity Framework Core ORM, local persistent storage
Networking	HttpClient + WebView2	REST API requests, cookie management, embedded web view
Native layer	C++ / Win32 Interop	Native DLL injection, process management, low-level system calls
Updater	Rust	Lightweight self-update component with resumable downloads and file-level delta replacement
Build	MSBuild + Cargo	Source Generators, incremental compilation, GitHub Actions CI/CD

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Requirements

Item	Requirement	Notes
OS	Windows 10 2004+	Build 19041 or later, Windows 11 recommended
Architecture	x64	64-bit systems only
Runtime	VC++ 2015–2022 x64	Download
WebView2	WebView2 Runtime	Any version, built into Windows 11

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Installation

1. Download the latest version from Releases
2. Extract to any directory
3. Run launcher.exe

First run requires VC++ 2015–2022 x64 and the WebView2 Runtime, both built into Windows 11.

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Building

Prerequisites

Dependency	Description
	dotnet.microsoft.com, preview channel
	Or build standalone with the dotnet CLI
	Select the corresponding workload in VS Installer
	rustup.rs, used to compile the updater-rs component

Clone the repository

git clone https://github.com/ky3-studio/ky3-Launcher.git
cd ky3-Launcher

Restore dependencies

dotnet restore src/launcher/launcher.csproj

Build

dotnet build src/launcher/launcher.csproj -c Release -p:Platform=x64

Build output goes to src/launcher/bin/Release/.

Run tests

dotnet test tests/ky3launcher.Tests/ky3launcher.Tests.csproj -c Release

Run benchmarks

dotnet run -c Release --project tests/ky3launcher.Benchmarks -- --filter *

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Project Structure

ky3-Launcher/
├── src/
│   ├── launcher/              ← Main project (WinUI 3)
│   │   ├── Core/              Infrastructure (DI, IO, caching, database, process management)
│   │   ├── Extension/         Extension methods (Span, String, Collection, memory management)
│   │   ├── Model/             Entity models and data structures
│   │   ├── Service/           Business services (planning calculator, wish analysis, check-in, notes)
│   │   ├── ViewModel/         MVVM ViewModel layer
│   │   ├── UI/                UI controls and styles
│   │   ├── Web/               HTTP clients and API wrappers
│   │   ├── Win32/             P/Invoke and native interop
│   │   └── Factory/           UI component factories (dialogs, file pickers, progress bars)
│   └── SourceGeneration/      Source Generators
├── Runner/                    C++ auto-start management (Windows Task Scheduler)
├── tests/
│   ├── ky3launcher.Tests/         Unit tests (341 tests)
│   └── ky3launcher.Benchmarks/    Performance benchmarks
├── module/                    Plugin DLLs
├── Installer/                 Installer scripts (Inno Setup)
└── .github/                   CI/CD, issue templates, Dependabot

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Contributing

Issues and Pull Requests are welcome to help improve the project.

Channel	Purpose
Issues	Report bugs, suggest features, discuss ideas
Pull Requests	Fix issues, add features, improve performance

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Acknowledgements

This project takes architectural inspiration from Snap Hutao. Thanks to DGP Studio and its community contributors for their open-source work.

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License

This project is open-sourced under the MIT license.

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Disclaimer

This is a third-party open-source tool with no affiliation with miHoYo / HoYoverse. Users assume all responsibility for any consequences of using this software.