Licensing

Codex Music is a research preview. Licensing for the engine, SDK, CLI, and example tools has not been announced, and the directory policy described further down is proposed, not shipped. The VST3 SDK and third-party content sections are real and apply to anything you build today.

Short version: our licensing is still to be announced, so do not plan around a particular answer yet. You keep ownership of what you write either way.

What the platform is licensed as

To be announced. The engine, SDK, CLI, contracts, and example tools are currently distributed as a research preview without a published open-source license. That means you should not assume a right to fork, redistribute, or vendor them into a product until terms are announced.

We would rather say that plainly now than imply a permissive license we have not actually granted. If you are deciding whether to build something commercial on this, the honest answer today is: wait for the licensing announcement, or ask.

The hub services — accounts, payments, hosting, review — are intended to be the commercial side, and they are not open. Where the line between the two ends up falling is part of what is still being settled.

The one upstream obligation

This part is not ours and is already true.

native/plugin-shell builds against Steinberg's VST3 SDK, which CMake fetches during the export. That SDK is dual-licensed: GPLv3, or Steinberg's free proprietary agreement. The choice is yours and it is made at distribution time, not at build time.

In practice: if your tool is GPLv3-compatible you are already fine. If you are shipping a closed-source or commercially licensed plugin, you need to sign Steinberg's proprietary agreement — it is free, but it exists, and it has its own terms including trademark use. This is an upstream constraint on the VST3 format itself, not a Codex Music policy, and it applies to every VST3 in existence.

The CLAP format is on the roadmap partly because it does not carry this.

What the directory would accept

Proposed, not in force — the directory is not open for submissions during the research preview.

The intent is to accept any OSI-approved license for open tools, and a commercial license if you are selling, provided it is stated, readable before purchase, and does not claim rights it cannot — notably it cannot restrict what users do with audio they render. The intent is also that a license is required, because an unlicensed tool is one nobody can legally use.

Treat all of that as direction. None of it is a commitment while the preview is running.

What you keep

You keep copyright in your kernel, your schema, your UI, and your presets. Nothing about the research preview changes that, and we do not ask for a copyright assignment. When publishing does open, the plan is that it grants only what is needed to host, display, and distribute your tool and run it in the browser playground — non-exclusive, so you can publish the same tool elsewhere at the same time.

If you charge money

Paid distribution is not available during the research preview, and the terms are not set. The models under consideration — a membership revenue pool, direct sale at a price you set, or free — are described as intentions elsewhere on the site, with the numbers marked as placeholders. Do not treat any of them as offered terms yet.

Third-party content

Two things catch people out, and both apply regardless of where our own licensing lands.

Samples and impulse responses you bundle carry their own licenses, and "found on a forum" is not one. Ship only material you have the right to redistribute, and record the provenance somewhere in the repo — you will be asked eventually.

Ported DSP. Reimplementing a published algorithm from its paper or its description is fine. Copying GPL'd DSP source into a kernel you then ship under different terms is not, and it is easy to do accidentally when you are reading someone's filter implementation while writing your own. If you ported from a specific source, credit it and match its license.

Changing your mind

Once terms exist and you have published under them, the ordinary rules of software licensing apply: you can relicense your own work going forward at any time, but you cannot revoke the license on versions already distributed. That is not a directory policy, it is how licensing works everywhere. It is worth planning your first license choice with that in mind.