Step-by-step SKILL.md packages an AI follows for a single kind of task.
A skill is a focused playbook - instructions, examples and constraints - that makes any model reliable at one job, from SQL reporting to changelog writing. The router fills a plan's skill slot with the best match for the request.
React 19 new APIs and patterns — use() hook, useActionState, useOptimistic, useFormStatus, ref as prop, form actions, document metadata, resource preloading, React Compiler, and migration from React 1
