Skip to content
/ LAUncher Public

LAUncher is a professional-grade Audio Unit host application designed for macOS.

License

View license
1 star 0 forks Branches Tags Activity
Star
Notifications You must be signed in to change notification settings

profmitchell/LAUncher

BranchesTags

Repository files navigation

LAUncher

A powerful, modern macOS Audio Unit host for both AU 2 and AUv3 plugins

Built with SwiftUI and AVFoundation

macOS Swift Xcode

Overview

LAUncher is a professional-grade Audio Unit host application designed for macOS. It provides a clean, modern interface for loading and using both traditional AU 2 plugins and modern AUv3 app extensions. Whether you're a music producer, sound designer, or audio enthusiast, LAUncher offers the tools you need to work with your favorite plugins.

Key Features

  • 🎹 Universal Plugin Support - Load both AU 2 (traditional) and AUv3 (app extension) plugins seamlessly
  • 🎨 Customizable Themes - Choose from built-in themes or create your own custom color schemes
  • ⌨️ QWERTY Piano - Built-in QWERTY keyboard for playing notes without a MIDI controller
  • 🎛️ MIDI Learn - Map MIDI CC messages to plugin parameters with intuitive learn mode
  • 🎚️ Transport Control - Play/pause transport with accurate BPM sync for tempo-synced effects
  • 📊 Parameter Export - Export plugin parameters as JSON for backup and sharing
  • 🤖 AI Integration - Built-in MCP (Model Context Protocol) server for AI-powered workflows
  • 🎯 Low Latency - Optimized audio engine for real-time performance
  • 🎨 Modern UI - Beautiful SwiftUI interface with resizable toolbar and sidebar inspector

Screenshots

Main Interface Plugin View MIDI Learn
Inspector Panel Theme Selection QWERTY Piano

Video Demo

🎥 Watch Demo Video on YouTube Shorts

Requirements

  • macOS: 15.7 or later
  • Xcode: 15.0 or later
  • Swift: 5.0+

Installation

Building from Source

  1. Clone the repository:

    git clone <repository-url>
cd LAUncher

  2. Open the project in Xcode:

    open LAUncher.xcodeproj

  3. Build and run:

    • Select the "LAUncher" scheme
    • Choose your Mac as the destination
    • Press ⌘R to build and run

Plugin Locations

LAUncher automatically discovers plugins from standard macOS locations:

  • /Library/Audio/Plug-Ins/Components/ (system-wide plugins)
  • ~/Library/Audio/Plug-Ins/Components/ (user-specific plugins)

Usage

Getting Started

  1. Launch LAUncher
  2. Load a Plugin - Click "Load Plugin…" in the toolbar to browse available plugins
  3. Select a Plugin - Choose from the list of discovered Audio Units
  4. Play Notes - Use MIDI input, QWERTY Piano keyboard, or the on-screen keyboard
  5. Adjust Parameters - Use the plugin's native UI to tweak settings
  6. Control Transport - Use the play/pause button to control BPM-synced effects

Features Guide

QWERTY Piano

Enable QWERTY Piano to use your QWERTY keyboard as a MIDI controller. The on-screen keyboard can be toggled on/off and repositioned by dragging.

MIDI Learn

  1. Click "MIDI Learn" in the More menu
  2. Click a parameter in the plugin UI
  3. Move a MIDI CC control on your device
  4. The mapping is saved automatically

Themes

Choose from built-in themes (Dark, Light, Midnight, Sunset, Ocean, Forest, Neon, Monochrome, Amethyst, Emerald, Fire) or create custom themes. Themes update immediately when selected. Access themes from the More menu.

Transport Control

The transport play/pause button controls tempo synchronization. When playing, plugins like Serum will sync their LFOs and effects to the host BPM.

Inspector Panel

Toggle the sidebar inspector (right side) to access:

  • Audio device selection (Input/Output)
  • MIDI input selection
  • Plugin information

Left Sidebar

The left sidebar provides quick access to:

  • Plugin loading and management
  • Transport controls (BPM, Play/Pause)
  • Engine status and controls
  • Quick tools (MIDI Learn, MCP Tools, AI Chat)
  • QWERTY Piano toggle

MCP (Model Context Protocol) Integration

LAUncher includes a built-in MCP server that enables AI-powered workflows for plugin control and patch management. The MCP server runs locally on port 5555 and exposes tools for interacting with your plugins programmatically.

MCP Server Features

The MCP server provides the following tools:

  1. get_parameters - Retrieve all parameters from the current plugin with filtering options
  2. set_parameters - Batch update multiple parameter values
  3. get_patch_snapshot - Get a structured snapshot of the current patch state
  4. set_patch_snapshot - Apply a patch snapshot by ID or inline object
  5. save_patch_to_library - Save patches to a local JSON library with metadata
  6. analyze_patch - Get musical analysis and timbre descriptions
  7. explain_parameters - Get explanations of what parameters do in musical terms

Using MCP Tools

Access MCP tools from the toolbar "More" menu → "MCP Tools". The MCP server runs automatically when LAUncher starts and is accessible at http://localhost:5555.

MCP Server Implementation

The MCP server is implemented as a standalone Node.js/TypeScript server (dev/mcp/launcher-server.js) that communicates with LAUncher via HTTP API. See MCP-PRD.md for detailed API documentation.

Example MCP Usage

{
  "method": "tools/call",
  "toolName": "get_parameters",
  "arguments": {
    "filter": {
      "pathPrefix": "Filter",
      "onlyAutomatable": true
    }
  }
}

For more information, see:

  • MCP-PRD.md - Complete MCP server specification
  • MCP-SERVER-STATUS.md - Server implementation status
  • dev/mcp/launcher-server.js - MCP server implementation

Supported Plugin Types

LAUncher supports all standard Audio Unit types:

  • Music Device (Instruments) - Synthesizers, samplers, drum machines
  • Effects - Reverb, delay, distortion, EQ, compression, etc.
  • Generators - Tone generators, noise sources
  • Mixers - Audio mixing and routing
  • Panners - Stereo panning and spatial audio
  • Format Converters - Sample rate and format conversion
  • Offline Effects - Non-real-time processing

Architecture

Project Structure

LAUncher/
├── LAUncher/
│   ├── App/
│   │   ├── LAUncherApp.swift          # App entry point
│   │   └── ContentView.swift           # Root content view
│   ├── Managers/
│   │   ├── AudioEngineManager.swift   # Audio engine and plugin loading
│   │   ├── PluginHostSession.swift    # Plugin state management
│   │   ├── MidiManager.swift          # MIDI input handling
│   │   ├── ThemeManager.swift         # Theme management
│   │   └── ...
│   ├── Models/
│   │   ├── AppTheme.swift             # Theme definitions
│   │   └── MidiTypes.swift            # MIDI data models
│   ├── Views/
│   │   ├── RootHostView.swift         # Main window view
│   │   ├── PluginPickerView.swift     # Plugin selection UI
│   │   ├── PluginCanvasView.swift     # Plugin UI container
│   │   ├── TopBarView.swift           # Toolbar controls
│   │   ├── StatusBarView.swift         # Status bar display
│   │   └── ...
│   └── Resources/
│       ├── Assets.xcassets            # App icons and assets
│       └── LAUncher.entitlements      # App entitlements
└── LAUncher.xcodeproj/

Key Components

  • AudioEngineManager: Handles AVAudioEngine setup, plugin instantiation, and host sync blocks
  • PluginHostSession: Coordinates plugin state, MIDI, audio devices, and UI state
  • ThemeManager: Manages theme selection and custom theme persistence
  • MidiManager: Handles MIDI input from devices and virtual sources

Troubleshooting

Plugins Not Loading

If you encounter error -3000 or plugins won't load:

  1. Check Entitlements: Ensure the app has been rebuilt after entitlement changes
  2. Verify Installation: Check that plugins are properly installed in the Components directories
  3. Check Compatibility: Verify plugin compatibility with your macOS version
  4. Validate Plugins: Try validating plugins using: auval -a

Sandbox Restrictions

This app requires specific entitlements to load third-party plugins:

  • com.apple.security.cs.disable-library-validation
  • com.apple.security.temporary-exception.audio-unit-host

These are configured in LAUncher.entitlements.

BPM Sync Issues

If plugins aren't syncing to BPM:

  1. Ensure the transport is playing (play button should show pause icon)
  2. Check that the plugin supports host tempo sync
  3. Verify BPM is set correctly in the toolbar

Development

Building

  1. Open LAUncher.xcodeproj in Xcode
  2. Select the "LAUncher" scheme
  3. Choose your Mac as the destination
  4. Build (⌘B) or Run (⌘R)

Code Style

  • Follow Swift naming conventions
  • Use @MainActor for UI-related code
  • Prefer ObservableObject for state management
  • Use SwiftUI best practices for view composition

License

Personal Use License

Copyright © 2025 Mitchell Cohen
Professor of Sound Design & Production @ Berklee College of Music
Newton, MA

All Rights Reserved

This software is provided for personal, non-commercial use only. You may use, study, and modify this software for your own personal purposes.

You may NOT:

  • Sell, rent, lease, or commercialize this software
  • Use this software for any commercial or profit-generating purpose
  • Redistribute, republish, or distribute this software
  • Create derivative works for distribution

See LICENSE for full terms and conditions.

For commercial licensing inquiries, please contact Mitchell Cohen.

Credits

LAUncher is developed and maintained by Mitchell Cohen.

Mitchell Cohen
Professor of Sound Design & Production @ Berklee College of Music
2025 Newton, MA

All Rights Reserved

Built with:

  • SwiftUI for modern, declarative UI
  • AVFoundation for audio processing
  • AudioToolbox for Audio Unit integration
  • CoreAudio for low-level audio control

Acknowledgments

Thanks to the macOS audio development community for their contributions to Audio Unit documentation and best practices.

LAUncher - Professional Audio Unit Hosting for macOS

Made with ❤️ by Mitchell Cohen

About

LAUncher is a professional-grade Audio Unit host application designed for macOS.

Resources

Readme

License

View license
Activity

Stars

1 star

Watchers

0 watching

Forks

0 forks
Report repository

Releases

No releases published

Packages

No packages published

Languages