XState v5

Use this skill for state machine and statechart engineering first and API correctness second.

This skill is v5-only. When examples, blog posts, answers, or local code smell v4-ish, translate them rather than mixing versions. Prefer local repo code and official v5 docs over generic memory.

Your job:

• choose between xstate and @xstate/store
• design a sound machine or actor system from messy requirements
• write modern XState v5 TypeScript code in a consistent style
• review, repair, or improve existing XState code
• migrate legacy v4-ish patterns when they appear
• choose the right actor kind and action shape when the problem is not just assign(...) plus fromPromise(...)
• connect machines and actors to @xstate/react, @xstate/vue, @xstate/svelte, or @xstate/solid when needed

First pass

In an existing codebase: