kern

A desktop server manager for Windows, macOS, and Linux. Register any project as a server instance, configure it via plugins, and control its lifecycle from a clean custom UI.

Manage any server instance — Minecraft, bots, APIs — with a live terminal, plugin extensibility, and graceful lifecycle control.

Features

• Server Registry: Register, edit, and remove server instances with custom paths and configuration
• Lifecycle Controls: Start / stop / restart / install with graceful shutdown (Minecraft world saves complete)
• Live Terminal: Stream process output with ANSI colors, send stdin commands
• Plugin System: Extend kern with .kern packages defining custom launch commands, config forms, and UI panels
• File Editor: Browse and edit files within instance directories (with path traversal protection)
• Process Telemetry: Real-time CPU/RAM monitoring per-instance and host-wide
• Auto-Updater: Signed in-app updates via GitHub Releases
• Multi-Runtime Support: Minecraft servers (Paper, Purpur, Fabric, Forge, NeoForge) and any executable (Node.js, Rust bots, etc.)

Quick Start

# Install dependencies
bun install

# Run development build
bun tauri dev

Navigate to the Plugins page to install server type plugins, then register instances pointing to your server directories.

Plugin System

Plugins extend kern's capabilities through .kern zip archives containing:

• manifest.json — defines lifecycle commands (install/start/stop), configuration schema, and scaffold files
• ui.js (optional) — custom React component for UI panels, tabs, and toolbar actions

Plugins can be installed via:

• The Plugin Manager UI (drag-and-drop or file picker)
• Double-clicking .kern files in the OS file manager (deep link support)

Plugins live in <app_data>/plugins/ and may declaratively:

• Generate server forms with dropdowns, text fields, and cascading defaults
• Provide starter files via the scaffold system
• Register custom tabs, toolbar actions, and sidebar items
• Override default lifecycle steps (e.g., custom start commands for Rust bots)

Recommended IDE Setup

• VS Code + Tauri + rust-analyzer

Development

bun install
bun tauri dev

Building & Releasing

Releases are built locally and distributed through GitHub Releases; the in-app updater polls releases/latest/download/update.json for new versions.

First-time setup

Generate a signing keypair (the public key is embedded in tauri.conf.json, the private key is gitignored at src-tauri/updater.key):

bun x tauri signer generate -w src-tauri/updater.key -p ""

Copy src-tauri/.env.example to src-tauri/.env and fill in the key path / password if you set one.

Cutting a release

# Cross-platform (Git Bash / Linux / macOS)
./deploy.sh [new_version]      # e.g. ./deploy.sh 0.2.0

deploy.sh handles: version bumping across package.json, tauri.conf.json, and Cargo.toml → bun tauri build → artifact packaging (.exe.zip / .tar.gz / .dmg.gz) → minisign signing → update.json generation with multi-platform merge support.

After it finishes, create a v{version} GitHub release and upload:

• the installer (.exe / .AppImage / .dmg)
• the signed archive (.exe.zip / .tar.gz / .dmg.gz)
• update.json

Multi-platform releases

Run ./deploy.sh <version> on each platform with the same version argument. Each run merges its platform entry into update.json (using update.json.prev as the base), so a single update.json ends up covering every platform.

Custom Windows installer skin

The NSIS installer uses a custom frameless skin (the nsNiuniuSkin DirectUI engine) styled in the kern palette — near-black with a signal-green accent and the Signal Radar logo. The skin lives under src-tauri/windows/nsis-skin/:

• skin/ — XML page layouts + PNG assets (buttons, checkboxes, caption controls, progress bar, logo, backgrounds). Committed.
• skin.zip — the zipped skin loaded at install time. Gitignored; regenerated by bun run installer:skin.
• installer.nsi — the Tauri NSIS template (install/uninstall lifecycle, shortcuts, registry, WebView2, updater /P//R handling).
• The four nsNiuniuSkin*.dll engine plugins.

The PNGs are generated from inline SVG via @resvg/resvg-js (no Python/Pillow needed), sourcing the kern palette from src/styles/global.css. bun tauri build runs scripts/prepare-nsis.mjs automatically (via beforeBuildCommand) to stage skin.zip; only re-run the asset generator when the palette or logo changes:

bun run installer:assets   # regenerate all skin PNGs + skin.zip
bun run installer:skin     # re-zip skin/ only (after editing XML)