Apollo Sandbox now supports subgraph functionality, allowing developers to work with locally-running graphs and run checks to ensure that changes won't break composition or operations against the federated graph. Users can load a subgraph in Sandbox, explore its schema, and run operations without manual refresh. The tool also allows users to compare their local schema with registered subgraphs in Studio and run checks to prevent breaking changes. These features are available on Team and Enterprise plans only and require a Studio account with access to Checks.