# XState 6.0.0-alpha.51

- Product: XState (https://whatsnew.fyi/product/xstate)
- Vendor: Stately
- Date: 2026-09-03
- Version: 6.0.0-alpha.51
- Original notes: https://github.com/statelyai/xstate/releases/tag/xstate%406.0.0-alpha.51
- Permalink: https://whatsnew.fyi/product/xstate/releases/6.0.0-alpha.51
- Labels: Pre-release

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

---

- **changed** — Improve setup() state contracts with typed structural metadata, recursive state input requirements for composite and parallel entry, history-default validation, strongly typed relative targets, and shared input requirements for literal target sets
- **changed** — State-level context schemas now refine the root context schema instead of replacing it, allowing narrowed context fields while retaining all root context fields in state actions, transitions, and narrowed snapshots

###### Minor Changes

- 29dae8c: Improve `setup(...)` state contracts with typed structural metadata, recursive
  state input requirements for composite and parallel entry, history-default
  validation, strongly typed relative targets, and shared input requirements for
  literal target sets.
- b44d9cb: State-level context schemas now refine the root context schema instead of
  replacing it. Declare only the fields narrowed by a state while retaining all
  root context fields in state actions, transitions, and narrowed snapshots.
  Nested states retain active ancestor refinements, and `xstate/fsm` uses the
  same refinement semantics.
  
  ```ts
  const machine = setup({
    schemas: {
      context: z.object({
        requestId: z.string(),
        draft: z.string().optional()
      })
    },
    states: {
      reviewing: {
        schemas: { context: z.object({ draft: z.string() }) }
      }
    }
  }).createMachine({
    context: { requestId: 'req-1' },
    // ...
  });
  ```