plugin-example

Placement	compiled-in (in-process)
Source	github.com/opencharly/charly/candy/plugin-example
Version	2026.176.1400
Candy	plugin-example

This plugin is listed in charly/charly.yml’s compiled_plugins:, so its providers are compiled into the charly binary and register in-process.

Providers

The reserved words this plugin serves:

• exampleprobe — verb class

What it does

Reference plugin candy for the exampleprobe check verb (a deterministic pass-with-marker probe). Its Go lives IN the candy (importable provider package + cmd/serve shim) — COMPILED INTO charly when listed in charly.yml compiled_plugins: (the default, registered in-process via registerCompiledPlugin), and served OUT-OF-PROCESS over gRPC by the shim when not. The canonical “a plugin is a candy” example — same authoring/discovery/validation/ADE as any candy, plus a plugin: block. Companion of candy/plugin-example-external (now identical in shape; the in-charly-module builtin form was retired).

Parameter schema

The CUE schema below is the authoritative grammar for this plugin’s input. It is the same single source that generates the plugin’s Go parameter types and answers the runtime Describe RPC, so this page cannot disagree with either.

schema/exampleprobe.cue

// The reference BUILT-IN plugin's OWN CUE schema — the typed plugin_input for the
// `exampleprobe` verb. It is the SINGLE SOURCE for this plugin's params, used two
// ways (the same contract an external plugin and core `spec` use):
//
//  1. GENERATE the Go param struct — `cue exp gengotypes` (driven by task cue:gen,
//     which wraps this with `package params` + `@go(params)`) emits
//     ../params/cue_types_gen.go, so the provider decodes plugin_input into a TYPED
//     struct, never a hand-parsed map.
//  2. VALIDATE authored input AT RUNTIME — the builtin serves this source over the
//     Describe channel (InProcTransport) exactly like an external serves it over
//     gRPC; the host splices it onto the base (base ++ plugin) and validates every
//     authored `exampleprobe` step's plugin_input against #ExampleprobeInput.
//
// SELF-CONTAINED: it references NO base def, so it compiles standalone (gengotypes +
// the load-gate compile) AND splices onto the base — the base ++ plugin splice
// exists to detect a def-name collision with the base, not to resolve base refs.
#ExampleprobeInput: {
  // marker — a NON-EMPTY string the provider echoes back as the result message,
  // proving the value round-trips author -> provider -> result. The host enforces
  // `& !=""` at validate time, so an authored empty / missing marker is a hard error.
  marker: string & !="" @go(Marker)
}

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See also the candy reference for this candy’s install surface.