This site describes solve-engine as it is on main: 2.43.0, which npm does not have yet. npm installs 2.40.0, so a page may show an answer that version does not give yet.
pluginFunctionRegistry
const pluginFunctionRegistry: Record<number, PluginFunctionHandler> = defaultEngineContext.pluginFunctions;Defined in: packages/engine/src/vm/VMBuiltins.ts:2305
Registry of package-registered functions, indexed by the number pushed as an
operand of OpCode.CALL_PLUGIN.
Functions may return a promise. The orchestrator resolves it and re-executes rather than blocking the VM.
Populated declaratively via IEnginePackage.pluginFunctions at package-registration time. Entries are cleared on unregister.