Class GrpcContextKeys

java.lang.Object
org.a2aproject.sdk.transport.grpc.context.GrpcContextKeys
public final class GrpcContextKeys extends Object
Shared gRPC context keys for A2A protocol data.

These keys provide access to gRPC context information stored in Context, enabling rich context access in service method implementations similar to Python's grpc.aio.ServicerContext.

Usage Example

public void processRequest(ServerCallContext context) {
    // Access gRPC context information
    Context grpcContext = Context.current();
    String method = GrpcContextKeys.GRPC_METHOD_NAME_KEY.get(grpcContext);
    Metadata metadata = GrpcContextKeys.METADATA_KEY.get(grpcContext);
    String peerInfo = GrpcContextKeys.PEER_INFO_KEY.get(grpcContext);

    // Access A2A protocol headers
    String version = GrpcContextKeys.VERSION_HEADER_KEY.get(grpcContext);
    String extensions = GrpcContextKeys.EXTENSIONS_HEADER_KEY.get(grpcContext);
}

Context Population

These context keys are populated by server interceptors (typically A2AExtensionsInterceptor) that capture request metadata and store it in the gRPC context before service methods are called.

See Also:

  • Field Details

    • VERSION_HEADER_KEY

      public static final io.grpc.Context.Key<String> VERSION_HEADER_KEY
      Context key for storing the a2a-version header value. Set by server interceptors and accessed by service handlers.

    • EXTENSIONS_HEADER_KEY

      public static final io.grpc.Context.Key<String> EXTENSIONS_HEADER_KEY
      Context key for storing the a2a-extensions header value. Set by server interceptors and accessed by service handlers.

    • METADATA_KEY

      public static final io.grpc.Context.Key<io.grpc.Metadata> METADATA_KEY
      Context key for storing the complete gRPC Metadata object. Provides access to all request headers and metadata.

    • GRPC_METHOD_NAME_KEY

      public static final io.grpc.Context.Key<String> GRPC_METHOD_NAME_KEY
      Context key for storing the method name being called. Equivalent to Python's context.method() functionality.

    • METHOD_NAME_KEY

      public static final io.grpc.Context.Key<String> METHOD_NAME_KEY
      Context key for storing the method name being called. Equivalent to Python's context.method() functionality.

    • PEER_INFO_KEY

      public static final io.grpc.Context.Key<String> PEER_INFO_KEY
      Context key for storing the peer information. Provides access to client connection details.

    • METHOD_MAPPING

      public static final Map<String,String> METHOD_MAPPING
      Mapping from gRPC method names to A2A protocol method names.

      This mapping translates gRPC protobuf method names to their corresponding A2A protocol method name constants for consistent method identification across all transports.

      Method Mappings:

      • SendMessage → SendMessage
      • SendStreamingMessage → SendStreamingMessage
      • GetTask → GetTask
      • ListTask → ListTasks
      • CancelTask → CancelTask
      • SubscribeToTask → SubscribeToTask
      • CreateTaskPushNotification → CreateTaskPushNotificationConfig
      • GetTaskPushNotification → GetTaskPushNotificationConfig
      • ListTaskPushNotification → ListTaskPushNotificationConfigs
      • DeleteTaskPushNotification → DeleteTaskPushNotificationConfig
      See Also: