flutter_vst3 0.1.2

Flutter/Dart framework for building VST® 3 plugins with Flutter UI and pure Dart audio processing. Provides the interface between Dart audio processing code and the Steinberg VST® 3 SDK C++ infrastructure.

flutter_vst3

Flutter/Dart framework for building VST® 3 plugins with Flutter UI and pure Dart audio processing.

VST® is a registered trademark of Steinberg Media Technologies GmbH, registered in Europe and other countries.

Overview

flutter_vst3 is a complete framework that enables you to build professional VST® 3 audio plugins using Flutter for the UI and Dart for real-time audio processing. The framework auto-generates all C++ VST® 3 boilerplate code - you write only Dart and Flutter.

For complete architecture documentation and examples, see the main project README.

Features

• ✅ Flutter UI - Build beautiful, reactive plugin interfaces
• ✅ Pure Dart DSP - Write audio processing in familiar Dart syntax
• ✅ Auto-Generated C++ - Never write VST® 3 boilerplate
• ✅ Native Performance - Compiles to machine code, no runtime
• ✅ 3-Way Parameter Binding - DAW ↔ Flutter UI ↔ Parameters stay in sync
• ✅ Cross-Platform - macOS, Windows, Linux support

Quick Start

📖 Complete Step-by-Step Plugin Creation Guide

The guide covers everything you need to build your first VST® 3 plugin:

• Project setup and dependencies
• Parameter definition with auto-generated C++
• Building and testing your plugin
• Installation to system VST® 3 directory

API Reference

VST3Processor

Base class for all Dart VST® 3 processors:

abstract class VST3Processor {
  void initialize(double sampleRate, int maxBlockSize);
  void processStereo(List<double> inputL, List<double> inputR,
                    List<double> outputL, List<double> outputR);
  void setParameter(int paramId, double normalizedValue);
  double getParameter(int paramId);
  int getParameterCount();
  void reset();
  void dispose();
}

VST3Bridge

Main bridge for Flutter UI ↔ VST® host communication:

class VST3Bridge {
  // Register your processor
  static void registerProcessor(VST3Processor processor);
  
  // Initialize processor (called from C++ layer)
  static void initializeProcessor(double sampleRate, int maxBlockSize);
  
  // Process audio (called from C++ layer)
  static void processStereoCallback(/* FFI parameters */);
}

Examples

See the complete example plugins in the main repository:

• Flutter Reverb - Full reverb with Flutter UI
• Echo Plugin - Delay/echo with custom knobs

Requirements

• Dart SDK 3.0+
• Flutter SDK 3.0+
• CMake 3.20+
• Steinberg VST® 3 SDK
• C++17 compiler

Legal Notice

This framework is not affiliated with Steinberg Media Technologies GmbH. VST® is a trademark of Steinberg Media Technologies GmbH.

Users must comply with the Steinberg VST® 3 SDK License Agreement when distributing VST® 3 plugins. See: https://steinbergmedia.github.io/vst3_dev_portal/pages/VST+3+Licensing/Index.html

License

This project is licensed under the BSD 3-Clause License - see the LICENSE file for details.