federation-jvm

The SchemaTransformer automatically adds Federation type definitions and directives like _Any scalar and _Entity union, making schemas compatible without manual adjustments, as detailed in the graphql-java-support module README.

Includes CacheControlInstrumentation for operation-level cache management based on @cacheControl directives and FederatedTracingInstrumentation for generating trace data in federated operations, enhancing observability out-of-the-box.

Adds subscription support via Apollo's HTTP callback protocol for Spring GraphQL, complementing existing WebSocket support, which is useful for specific deployment scenarios like those using Apollo Router.

As an official Apollo project, it ensures compatibility with Apollo Federation standards and regular updates, reducing integration risks and providing community support through Apollo forums.