- Adds a new `marketRelationships` query and parent/child fields on `Market` in GraphQL Admin API v2026-10, enabling direct traversal of a store’s market hierarchy.
- Introduces `marketRelationshipsStatus.version` to detect asynchronous relationship rebuilds; apps should poll the version, restart pagination, and refetch data after changes.
- Existing apps require no changes—simply use API version 2026-10+ with the `read_markets` scope to access the new fields.