Registry Extensions

Registry extensions are host-specific metadata stored inside a normal Vix package.

They do not create a second registry. They do not change dependency resolution. They do not add a second lockfile. They only let a Vix host, such as Vix Note, discover extra capabilities from packages that were already published and installed through the normal registry workflow.

{
  "extensions": {
    "note": {
      "api": "1",
      "cellTypes": []
    }
  }
}

Why extensions are metadata

A package manager should have one source of truth for identity, version, repository, commit, and installation ownership. If Note extensions used a separate registry, Vix would need a second resolver, a second install state, and a second trust model for packages that are still just source repositories.

Vix avoids that split. A Note extension is installed with:

vix install -g softadastra/pyrelune

and listed with:

vix note --list-extensions

The extension appears because the installed package metadata contains extensions.note.

Supported hosts

The implemented extension host is:

note

Unknown extension hosts can be preserved as JSON metadata, but Vix Note only reads extensions.note.

Search

Extension summaries are copied to the package-level registry entry so search can filter without resolving a version.

vix search --extension note
vix search python --extension note
vix search --extension note --capability mime-output
vix search --extension note --type executable

vix search stays offline. It reads the local registry index created by vix registry sync.

Installation

Global installation records the version-level extension metadata in:

~/.vix/global/installed.json

or under the prefix selected by VIX_GLOBAL_PREFIX.

This installed manifest is what Vix Note reads during global extension discovery. The runtime command declared by an extension must be installed under the global bin/ directory, and package files installed by CMake are tracked so global uninstall can remove them later.

Current boundaries

The current Note extension system supports declarative cell types and one-shot external runtimes.

It does not automatically load extension JavaScript, arbitrary CSS, native .so or .dll plugins, persistent processes, or interactive permission prompts. Those features require a larger security model and are intentionally outside the first implemented extension API.