Questions about VST3 API and its licensing

Developer VST 3 SDK
1

I was looking into information about using rust to write VST3 plugins, and found a github project called RustAudio/vst3-sys.

The github page says that this code doesn’t use or wrap SDK code and instead just implements bindings for COM API that are compatible with VST3 API. I was wondering how this situation fits into VST3 licensing.

  1. Would a plugin that uses this or similar COM API bindings but no VST3 SDK code be able to call itself a VST3 plugin, or a VST3 compatible plugin?

  2. Would such a plugin be bound by VST3 SDK licensing conditions? That is, does the VST3 SDK license apply to all projects compatible with VST3 API, or only projects that use VST3 SDK code?

In both cases I’m assuming that only the official documentation was used as a source of information about VST3 API.

Thank you.

1 Like
2

As far as I understand, if your project is not using the SDK, it is not bound by the SDK license conditions. The ABI (memory layout of data structures, constants and function calls) are detailed in the public documentation, so anyone could use this information to build VST3 plugins in rust (or the language of their choice).

Note that VST is a trademark, so you will need to use the “VST” string and logo as required by Steinberg, no matter if you’re using the SDK or not.