Expose per-state schemas on machine state nodes

[asfktz]

Problem

setup() lets you declare schemas for individual states, but they never made it onto the compiled machine. Only the root-level schemas were merged in — anything declared under states was silently dropped:

import { setup, types } from 'xstate';

const machine = setup({
  states: {
    running: {
      schemas: {
        context: types<{ startedAt: number }>()
      }
    }
  }
}).createMachine({
  initial: 'running',
  states: {
    running: {}
  }
});

machine.states.running.schemas; // ❌ was undefined

This meant tooling that only has access to the machine (e.g. a per-state snapshot validator, docs generation, serialization) couldn't see the per-state schemas at all — they were only reachable through the setup() return value.

Fix

createMachine now recursively merges the setup states schema tree into the machine config, and StateNode exposes a schemas property:

machine.states.running.schemas?.context; // ✅ the schema you declared
machine.states.running.states.child.schemas; // ✅ works for nested states too

Merge rules follow the existing root-level behavior: setup schemas win over inline config schemas, and setup states with no matching config state are ignored.

Notes

• machine.states.X.schemas is typed as the loose SetupStateSchemas ({ context?; input? }), not the precise declared schema types. Narrowing it is a possible follow-up.
• Next_MachineConfig now omits schemas from the state-node config it extends, so the new per-state field doesn't collide with the machine-level schemas option (no change to the public createMachine surface).

[changeset-bot]

🦋 Changeset detected

Latest commit: 4d85b8c

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
xstate	Patch

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