Go plugin hello-world

Editions: Open Source · Free Cloud · Pro

Copy from sdk/go-plugin-build-sdk/examples/main.go. For a production plugin (GraphQL, REST, Console UI, publish), see the Cloudinary walkthrough.

1. Build the plugin binary for the engine OS/arch.
2. Place it under the engine plugin directory with config.yml declaring capabilities (not type).
3. Restart engine or POST /system/plugin/:id/restart so the host loads it.
4. In Console: Project Settings → Plugins → Add from catalog → Activate on one project.
5. Call project GraphQL (plg_*) or REST /{pluginId}/… with that project id. A second project without activation must not see the fields/routes.
6. Deactivate from the same settings page. Cache rebuilds; plg_* disappears.
7. Cleanup: deactivate, then delete the plugin directory / DELETE /system/plugin/:id as operator.

Handshake protocol_version stays 1. Do not add RPC methods for install vs activate.