afv-library/skills/building-omnistudio-callable-apex/assets/pattern_callable_vanilla.cls

/**
 * Vanilla System.Callable skeleton — flat args, no Open Interface coupling.
 * Use when callers pass flat args and no VlocityOpenInterface integration is required.
 *
 * Replace Industries_XxxCallable and actionOne with the actual class/action names.
 */
public with sharing class Industries_XxxCallable implements System.Callable {

    public Object call(String action, Map<String, Object> args) {
        Map<String, Object> input = args != null ? args : new Map<String, Object>();

        switch on action {
            when 'actionOne' {
                return actionOne(input);
            }
            when else {
                throw new IndustriesCallableException('Unsupported action: ' + action);
            }
        }
    }

    private Map<String, Object> actionOne(Map<String, Object> args) {
        // 1. Validate required keys (e.g. args.get('requiredKey'))
        // 2. Coerce types safely
        // 3. Run business logic (SOQL with WITH USER_MODE, DML with sharing)
        // 4. Return response envelope
        return new Map<String, Object>{
            'success' => true,
            'data'    => new Map<String, Object>()
        };
    }
}