Plugin Metadata and Entry Points

rfgen discovers installed extensions through Python entry points. The current public registry groups include rfgen.emitters, rfgen.channels, rfgen.labelers, rfgen.dataset_stores, rfgen.inference_clients, and rfgen.annotation.credentials. A plugin must implement the relevant public ABC and declare the matching entry point in its own pyproject.toml. The credentials group is a supported extension group; rfgen does not ship a credentials entry point in its own pyproject.toml or a bundled registry factory.

For example, an inference provider registers a BaseInferenceClient subclass under rfgen.inference_clients; its factory and completion contracts are documented in Annotators. A credential provider registers a BaseCredentialsProvider subclass under rfgen.annotation.credentials.

rfgen does not currently expose a PLUGIN metadata object, remote registry, plugin-card parser, compatibility negotiation, or a remote catalog listing. Do not copy those legacy design examples into an extension. Use rfgen list-nodes to inspect the installed local registry surface; it reports every role, not only sources and channels.