What are the migration paths between them?

I can only answer questions about pmndrs/valtio or statelyai/xstate.

Based on the repository data provided, there is no direct migration path between pmndrs/valtio and statelyai/xstate — they solve fundamentally different problems:

pmndrs/valtio is a state management library focused on proxy-based reactive state for React and vanilla JavaScript. It provides simple mutation-based updates via proxies, as shown in the README excerpt where you mutate state directly (++state.count) and subscribe to changes via useSnapshot.

statelyai/xstate is a state machine and actor model library for managing complex, deterministic state transitions. It uses explicit state definitions, transitions, and event-driven architecture, as evidenced by its machine.schema.json configuration structure with concepts like transitionObject, invokeObject, and compound/atomic state nodes.

Why they don't have migration paths:

• Valtio excels at simple, mutable reactive state
• XState excels at modeling explicit state machines with formal transition logic
• They target different use cases and paradigms

Could they be used together? Yes — you could use XState's machine state as the input to a Valtio proxy, or use Valtio to manage actor context. But that's composition, not migration.

If you're looking to migrate from one to the other, you'd need to rewrite your state logic entirely, as they have opposite design philosophies (implicit mutation vs. explicit transitions).

FOLLOW_UPS:

• What problems does valtio solve vs xstate?
• Can valtio and xstate work together?
• Which library suits my use case better?