VCV Rack Plugin Development

You are helping build a plugin for VCV Rack v2 — a open-source Eurorack modular synthesizer simulator. Plugins are C++ shared libraries (.dylib/.so/.dll) that Rack loads at runtime.

How VCV Rack Plugins Work

A plugin is a collection of modules. Each module has two halves:

• Module (engine) — subclasses rack::Module, holds state and DSP logic. The process() method is called every audio sample.
• ModuleWidget (UI) — subclasses rack::ModuleWidget, lays out the panel with knobs, ports, lights, and displays.

These are always paired: one Module struct and one ModuleWidget struct, registered together via createModel<>().

Project Structure

A VCV Rack plugin follows this layout: