Can a Codex Marketplace plugin download a platform-specific native binary from GitHub Releases?

I’m preparing a cross-platform Codex plugin for Marketplace submission.

The plugin has native helpers for:

  • Windows x64
  • macOS arm64
  • macOS x64

Each self-contained build is ~45 MB, so a combined ZIP exceeds the 50 MB upload limit.

Is it allowed for the submitted plugin ZIP to contain only the manifest/skill/scripts/assets, then on first run:

  • detect OS/architecture
  • download the correct binary from a pinned public GitHub Release
  • verify SHA-256
  • cache it locally
  • launch it

Or must all executables be included directly in the Marketplace ZIP?

If external download is allowed, are there requirements around:

  • signing/notarization
  • user approval
  • allowed download domains