This is your go-to when you're writing System.Callable classes for Salesforce Industries or migrating legacy VlocityOpenInterface code. It walks you through the full pattern: gathering requirements, designing the input/output contract with a consistent response envelope, implementing action dispatch with proper CRUD/FLS enforcement, and writing tests that cover positive, negative, contract, and bulk scenarios. The 120-point scoring rubric keeps you honest about security and bulkification. Best part is the dual-mode support: it shows you how to build callables that work with both the modern System.Callable interface and the old VlocityOpenInterface2 signature using shared logic under the hood. If you're extending OmniStudio or DataRaptors with custom Apex, this will save you from reinventing the wheel.
npx skills add https://github.com/forcedotcom/sf-skills --skill building-omnistudio-callable-apex