Agents

An agent edits a page through the same path a person does: it sends the Builder's own Applied Message, so its edit is checked, undoable, autosaved and revisioned like any other. Composition.operationSchema(Site) is the tool's input, generated from the Catalog:

Agent.expose(Message, {
  GotEditorMessage: Agent.variant({
    name: 'edit_page',
    description: 'Insert, move, remove or configure blocks on the page',
    input: Composition.operationSchema(Site),
    toMessage: op => ({ message: PageForm.control('document').send(BuilderMessage.Applied({ op })) }),
  }),
})

• An insert names one of the Catalog's Blocks, as a literal, with that Block's props as they are stored, so a Block outside the Catalog is refused by the tool's own input schema before apply sees it. apply checks the rest.
• Each insert carries its Block's description, when it has one (Block.words), so the tool's schema says what each Block is for.
• The agent mints the ids of what it adds (composition:id-taken for one in use), and reads the page as Composition.describe(Site, document), ids and props included.
• A pattern (see Patterns) goes in by UsePattern, whose ids name exactly the pattern's nodes.
• examples/cms has one, pageAgent.ts.