GraphQL Overview

@heronjs/gql@4.0.0 provides schema-first GraphQL with decorated resolvers. Register schema classes in @Module({graphqls: [...]}) to enable the extension.

GraphQL shares the application’s native Fastify HTTP listener. Its default endpoint is /graphql; @GraphQL declares schema metadata and @Resolver marks query/mutation handlers. Parameter decorators expose resolver arguments, parent, context and GraphQL execution information.

Resolvers support values, Promises and Observables with first-emission semantics. Guard evaluation is awaited, unexpected resolver errors are masked, and disposing the extension cancels active execution.

Follow the Quick Start for a complete application and query.