Plugin contracts and extension points

This page is Plugin Development → Backend → Advanced: what plugin contracts are, how they relate to the rest of the backend plugin surface, and where to implement them. For file layout and step-by-step wiring, follow the Golden Path — Backend.

Plugin contracts

A plugin contract is a named service object your plugin registers so other plugins (or core) can call it without going through HTTP. Typical uses: shared helpers, cross-plugin orchestration, or stable “API surfaces” that stay versioned with your npm package.

• You choose the contract id and the shape of the exported object (method names are entirely up to you).
• Registration happens from backend code — see Plugin index.ts for where registerPluginContract fits in the startup sequence.
• Convention still helps: if your service methods mirror predictable CRUD-style names (get, getAll, create, update, delete, …), other plugins and future generic tooling have a much easier time consuming your contract. The Golden Path — Service page ties this to routes and payloads.

For cross-plugin patterns in more depth (naming, evolution), see Cross-plugin communication on Service.

Other extension points (same backend plugin)

Beyond contracts, a backend plugin usually touches several registration hooks that the loader and generators observe:

• HTTP routes — fastify.get / post / … plus raclette config on each route (store action type, broadcast channels). See Routes.
• Payload handlers — how stored documents become UI-facing payload rows. See Helpers.
• Schemas — TypeBox (or other) registration for validation and shared typing. See Schema.
• Frontend generation — registerForFrontendGeneration / automatic registration and generated-config.ts. See Frontend entity mapping, the generated config FAQ, and Backend overview — generated-config lifecycle.

Full backend reference (single document)

The Plugin Backend Side guide is still available as one consolidated document alongside the split between Fundamentals, Backend overview, and Golden Path; use it when you want the whole backend side story in linear form.