RuntimeFunction

A RuntimeFunction is a class with a run() method that Hercules calls when an execution request arrives from Aquila. It is the implementation layer — all logic lives here.

import { Identifier, Signature, Name, OmitRuntimeFunction } from '@code0-tech/hercules';

Overview

When action.registerRuntimeFunction() is called, Hercules automatically also registers a FunctionProps entry using the same metadata. Apply @OmitRuntimeFunction to suppress this and register the public definition manually via action.registerFunction().

The descriptor stored in action.runtimeFunctions is documented on the RuntimeFunctionManager page.

`RuntimeFunctionClass`

type RuntimeFunctionClass<T extends RuntimeFunctionRunnable = RuntimeFunctionRunnable> =
  new () => T;

The constructor type accepted by action.registerRuntimeFunction().

Example

@Identifier('fibonacci_runtime')
@Signature('(n: number): number')
@OmitRuntimeFunction()
export class FibonacciRuntimeFunction {
  run(context: FunctionContext, n: number): number {
    if (n <= 1) return n;
    return this.run(context, n - 1) + this.run(context, n - 2);
  }
}

Error Handling

Throw a RuntimeError to signal a recoverable error back to the platform:

import { RuntimeError } from '@code0-tech/hercules';

run(context: FunctionContext, input: string): string {
  if (!input) throw new RuntimeError('INVALID_INPUT', 'Input must not be empty');
  return input.toUpperCase();
}

Mark the function with @ThrowsError so the platform knows to handle the error case.

Decorators

Decorator	Description
`@Identifier`	Sets the unique runtime identifier
`@Name`	Sets the localised display name
`@Description`	Sets a short localised description
`@Documentation`	Sets long-form documentation text
`@DisplayMessage`	Sets the summary text shown in the flow UI
`@Alias`	Sets alternative search terms
`@DeprecationMessage`	Marks the function as deprecated
`@Signature`	Sets the TypeScript-like signature string
`@DisplayIcon`	Sets the icon shown in the flow UI
`@Parameter`	Adds a parameter definition
`@Design`	Attaches a visual design token
`@ThrowsError`	Marks the function as capable of throwing a RuntimeError
`@OmitRuntimeFunction`	Prevents auto-generation of a public function definition