XState

Use XState when the domain has meaningful modes, transitions, async lifecycle, cancellation, guards, delays, or actor boundaries. The goal is not "state management"; the goal is to make the process explicit, typed, inspectable, and hard to misuse.

Core Standard

• Prefer setup({ types, actors, actions, guards, delays }).createMachine(...) for typed machines with named implementations.
• Put finite modes in states.
• Put durable facts in context.
• Put side effects behind actors, actions, guards, and delays.
• Put request data in invoke.input.
• Put UI decisions on snapshots: matches, hasTag, can, and selected context.
• Initialize each actor instance with input.
• Define default implementations in setup(...); replace runtime implementations with .provide(...).
• Model later external changes as keyed remounts, domain events, or subscription actors.

Reading Guide

Read only the references needed for the task: