What problem does it solve? Public library APIs often ship with inconsistent naming, nullable field clusters, ambiguous error behavior, and platform-specific leaks that are hard to fix after release. This Skill provides a structured rule set for designing and reviewing predictable public API surfaces before implementation locks them in. ## Core Features & Use Cases - API Shape Rules: Enforces single sources of truth, option objects, discriminated unions, and explicit lifecycle handles instead of boolean clusters and half-initialized objects. - Async, Events, and React Guidance: Defines when to use Promises versus listener subscriptions, how to return cleanup handles, and how to layer hooks over imperative cores. - Error and Platform Design: Standardizes throwing real Error objects, modeling cross-platform capabilities, and avoiding workaround APIs baked into public contracts. - Use Case: Before publishing a React Native barcode scanning library, run this Skill to review the exported TypeScript surface, split scanner variants into separate capability APIs, and verify JSDoc documentation contracts. ## Quick Start Ask the assistant to review the public API of your TypeScript or React Native library using the api-design skill before implementation.
