Extension points

Core plugins expose extension points that third-party plugins contribute to declaratively through the manifest’s extensions[] array. Each entry names a qualified extension point id and carries the contribution payload:

plugin.json (excerpt)

{
  "extensions": [
    {
      "extensionPoint": "space.appos.core.notifications:channel",
      "...": "contribution payload fields (schema owned by the core plugin)"
    }
  ]
}

From the manifest schema (schemas/plugin-v1.json):

Extension contributions (fn-12 typed array) — the manifest-declarative delivery vehicle for core-plugin extension points (actions.definition, views.savedView, surfaces.contribution, sidecars.definition, notifications., input., ledger., llm., recipes/sequences definitions, clipboard EPs, scheduler.triggerKind/condition, entities.*)

Only extensionPoint is required per entry; the remaining fields are validated by the owning core plugin at replay time. Contributions are re-ingested on plugin activation, so manifest-declarative contributions behave identically to runtime-registered ones once bound.

Plugins can also declare their own extension points (extensionPoints manifest field + context.extensionPoints API) for other plugins to contribute to — see ExtensionPointsAPI in the API Reference.

Contribution surfaces

Contributing to an extension point requires the matching contributor permission scope. The scope catalog is the machine-readable signal for which contribution surfaces exist, grouped here by family:

Family	Contributor scopes
clipboard	clipboard.contentType.register, clipboard.source.register, clipboard.transform.register, clipboard.destination.register, clipboard.rule.register, clipboard.retention.predicate.register
interPlugin	interPlugin.contribute
events	events.serializer.register, events.sink.register
store	store.backend.register, store.migrator.register, store.indexer.register
vault	vault.type.register, vault.bridge.register, vault.rotator.register, vault.policy.contribute
actions	actions.register
palette	palette.contribute.scope
scheduler	scheduler.trigger.register, scheduler.condition.register, scheduler.action.register
resources	resources.provider.register
tokens	tokens.provider.register
entities	entities.type.register, entities.computedField.provide
views	views.register, views.layoutRenderer.register
surfaces	surfaces.contribute.sidebar.top, surfaces.contribute.sidebar.bottom, surfaces.contribute.pane.dashboard, surfaces.contribute.status.left
sidecars	sidecars.definition.register
notifications	notifications.channel.register, notifications.filter.register, notifications.action.register
input	input.channel.register, input.parser.register, input.intent.register, input.auth.register
webhook	webhook.route.register, webhook.route.register.unsigned, webhook.tunnel.register, webhook.signer.register
llm	llm.provider.register, llm.preprocessor.register, llm.postprocessor.register, llm.router.register
recipes	recipes.register
sequences	sequences.register

TODO — canonical extension-point catalog

The authoritative extension-point catalog — qualified ids (<corePluginId>:<point>), per-contribution payload schemas, and validation rules — is owned by the core plugins in the AppOS host repo and is not machine-readable from this SDK repo yet. The table above is derived from contributor permission scopes; per-point payload documentation will be generated once the host exports a machine-readable extension-point catalog.