refactor: Update A2A protocol to align with spec revision

README.md

@@ -612,24 +612,24 @@ client.deleteTaskPushNotificationConfigurations(
     new DeleteTaskPushNotificationConfigParams("task-1234", "config-4567", clientCallContext);
 ```
 
-#### Resubscribe to a task
+#### Subscribe to a task
 
 ```java
-// Resubscribe to an ongoing task with id "task-1234" using configured consumers
+// Subscribe to an ongoing task with id "task-1234" using configured consumers
 TaskIdParams taskIdParams = new TaskIdParams("task-1234");
-client.resubscribe(taskIdParams);
+client.subscribeToTask(taskIdParams);
 
-// Or resubscribe with custom consumers and error handler
+// Or subscribe with custom consumers and error handler
 List<BiConsumer<ClientEvent, AgentCard>> customConsumers = List.of(
-    (event, card) -> System.out.println("Resubscribe event: " + event)
+    (event, card) -> System.out.println("Subscribe event: " + event)
 );
 Consumer<Throwable> customErrorHandler = error -> 
-    System.err.println("Resubscribe error: " + error.getMessage());
+    System.err.println("Subscribe error: " + error.getMessage());
 
-client.resubscribe(taskIdParams, customConsumers, customErrorHandler);
+client.subscribeToTask(taskIdParams, customConsumers, customErrorHandler);
 
 // You can also optionally specify a ClientCallContext with call-specific config to use
-client.resubscribe(taskIdParams, clientCallContext);
+client.subscribeToTask(taskIdParams, clientCallContext);
 ```
 
 #### Retrieve details about the server agent that this client agent is communicating with

client/base/src/main/java/io/a2a/client/AbstractClient.java

@@ -318,7 +318,7 @@ public abstract void deleteTaskPushNotificationConfigurations(
             @Nullable ClientCallContext context) throws A2AClientException;
 
     /**
-     * Resubscribe to a task's event stream.
+     * Subscribe to a task's event stream.
      * This is only available if both the client and server support streaming.
      * The configured client consumers will be used to handle messages, tasks,
      * and update events received from the remote agent. The configured streaming
@@ -327,12 +327,12 @@ public abstract void deleteTaskPushNotificationConfigurations(
      * @param request the parameters specifying which task's notification configs to delete
      * @throws A2AClientException if resubscribing fails for any reason
      */
-    public void resubscribe(@NonNull TaskIdParams request) throws A2AClientException {
-        resubscribe(request, consumers, streamingErrorHandler, null);
+    public void subscribeToTask(@NonNull TaskIdParams request) throws A2AClientException {
+        subscribeToTask(request, consumers, streamingErrorHandler, null);
     }
 
     /**
-     * Resubscribe to a task's event stream.
+     * Subscribe to a task's event stream.
      * This is only available if both the client and server support streaming.
      * The configured client consumers will be used to handle messages, tasks,
      * and update events received from the remote agent. The configured streaming
@@ -342,13 +342,13 @@ public void resubscribe(@NonNull TaskIdParams request) throws A2AClientException
      * @param context optional client call context for the request
      * @throws A2AClientException if resubscribing fails for any reason
      */
-    public void resubscribe(@NonNull TaskIdParams request,
+    public void subscribeToTask(@NonNull TaskIdParams request,
                             @Nullable ClientCallContext context) throws A2AClientException {
-        resubscribe(request, consumers, streamingErrorHandler, context);
+        subscribeToTask(request, consumers, streamingErrorHandler, context);
     }
 
     /**
-     * Resubscribe to a task's event stream.
+     * Subscribe to a task's event stream.
      * This is only available if both the client and server support streaming.
      * The specified client consumers will be used to handle messages, tasks, and
      * update events received from the remote agent. The specified streaming error
@@ -359,14 +359,14 @@ public void resubscribe(@NonNull TaskIdParams request,
      * @param streamingErrorHandler an error handler that should be used for the streaming case if an error occurs
      * @throws A2AClientException if resubscribing fails for any reason
      */
-    public void resubscribe(@NonNull TaskIdParams request,
+    public void subscribeToTask(@NonNull TaskIdParams request,
                             @NonNull List<BiConsumer<ClientEvent, AgentCard>> consumers,
                             @Nullable Consumer<Throwable> streamingErrorHandler) throws A2AClientException {
-        resubscribe(request, consumers, streamingErrorHandler, null);
+        subscribeToTask(request, consumers, streamingErrorHandler, null);
     }
 
     /**
-     * Resubscribe to a task's event stream.
+     * Subscribe to a task's event stream.
      * This is only available if both the client and server support streaming.
      * The specified client consumers will be used to handle messages, tasks, and
      * update events received from the remote agent. The specified streaming error
@@ -378,7 +378,7 @@ public void resubscribe(@NonNull TaskIdParams request,
      * @param context optional client call context for the request
      * @throws A2AClientException if resubscribing fails for any reason
      */
-    public abstract void resubscribe(@NonNull TaskIdParams request,
+    public abstract void subscribeToTask(@NonNull TaskIdParams request,
                                      @NonNull List<BiConsumer<ClientEvent, AgentCard>> consumers,
                                      @Nullable Consumer<Throwable> streamingErrorHandler,
                                      @Nullable ClientCallContext context) throws A2AClientException;

client/base/src/main/java/io/a2a/client/Client.java

@@ -152,7 +152,7 @@
  *
  * // Later, reconnect and resume receiving events
  * String taskId = "task-123";  // From original request
- * client.resubscribe(
+ * client.subscribeToTask(
  *     new TaskIdParams(taskId),
  *     List.of((event, card) -> {
  *         // Process events from where we left off
@@ -529,7 +529,7 @@ public void deleteTaskPushNotificationConfigurations(
     }
 
     /**
-     * Resubscribe to an existing task to receive remaining events.
+     * Subscribe to an existing task to receive remaining events.
      * <p>
      * This method is useful when a client disconnects during a long-running task and wants to
      * resume receiving events without starting a new task. The agent will deliver any events
@@ -551,27 +551,27 @@ public void deleteTaskPushNotificationConfigurations(
      * // ... client1 disconnects ...
      *
      * // Later, reconnect (client2)
-     * client2.resubscribe(
+     * client2.subscribeToTask(
      *     new TaskIdParams(taskId),
      *     List.of((event, card) -> {
      *         if (event instanceof TaskUpdateEvent tue) {
      *             System.out.println("Resumed - status: " +
      *                 tue.getTask().status().state());
      *         }
      *     }),
-     *     throwable -> System.err.println("Resubscribe error: " + throwable),
+     *     throwable -> System.err.println("Subscribe error: " + throwable),
      *     null
      * );
      * }</pre>
      *
-     * @param request the task ID to resubscribe to
+     * @param request the task ID to subscribe to
      * @param consumers the event consumers for processing events (required)
      * @param streamingErrorHandler error handler for streaming errors (optional)
      * @param context custom call context for request interceptors (optional)
-     * @throws A2AClientException if resubscription is not supported or if the task cannot be found
+     * @throws A2AClientException if subscription is not supported or if the task cannot be found
      */
     @Override
-    public void resubscribe(@NonNull TaskIdParams request,
+    public void subscribeToTask(@NonNull TaskIdParams request,
                             @NonNull List<BiConsumer<ClientEvent, AgentCard>> consumers,
                             @Nullable Consumer<Throwable> streamingErrorHandler,
                             @Nullable ClientCallContext context) throws A2AClientException {
@@ -588,7 +588,7 @@ public void resubscribe(@NonNull TaskIdParams request,
                 overriddenErrorHandler.accept(e);
             }
         };
-        clientTransport.resubscribe(request, eventHandler, overriddenErrorHandler, context);
+        clientTransport.subscribeToTask(request, eventHandler, overriddenErrorHandler, context);
     }
 
     /**

client/base/src/test/java/io/a2a/client/AuthenticationAuthorizationTest.java

@@ -1,6 +1,5 @@
 package io.a2a.client;
 
-import static io.a2a.spec.AgentCard.CURRENT_PROTOCOL_VERSION;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.mockserver.model.HttpRequest.request;
@@ -90,7 +89,6 @@ public void setUp() {
                         .description("Test skill")
                         .tags(Collections.singletonList("test"))
                         .build()))
-                .protocolVersions(CURRENT_PROTOCOL_VERSION)
                 .supportedInterfaces(java.util.Arrays.asList(
                         new AgentInterface(TransportProtocol.JSONRPC.asString(), AGENT_URL),
                         new AgentInterface(TransportProtocol.HTTP_JSON.asString(), AGENT_URL),

client/base/src/test/java/io/a2a/client/ClientBuilderTest.java

@@ -1,6 +1,5 @@
 package io.a2a.client;
 
-import static io.a2a.spec.AgentCard.CURRENT_PROTOCOL_VERSION;
 
 import java.util.Collections;
 import java.util.List;
@@ -41,7 +40,6 @@ public class ClientBuilderTest {
                                 .tags(Collections.singletonList("hello world"))
             .examples(List.of("hi", "hello world"))
             .build()))
-            .protocolVersions(CURRENT_PROTOCOL_VERSION)
             .supportedInterfaces(List.of(
                     new AgentInterface(TransportProtocol.JSONRPC.asString(), "http://localhost:9999")))
             .build();

client/transport/grpc/src/main/java/io/a2a/client/transport/grpc/GrpcTransport.java

@@ -142,7 +142,7 @@ public void sendMessageStreaming(MessageSendParams request, Consumer<StreamingEv
     public Task getTask(TaskQueryParams request, @Nullable ClientCallContext context) throws A2AClientException {
         checkNotNullParam("request", request);
         io.a2a.grpc.GetTaskRequest.Builder requestBuilder = io.a2a.grpc.GetTaskRequest.newBuilder();
-        requestBuilder.setName("tasks/" + request.id());
+        requestBuilder.setId(request.id());
         if (request.historyLength() != null) {
             requestBuilder.setHistoryLength(request.historyLength());
         }
@@ -164,7 +164,7 @@ public Task cancelTask(TaskIdParams request, @Nullable ClientCallContext context
         checkNotNullParam("request", request);
 
         io.a2a.grpc.CancelTaskRequest cancelTaskRequest = io.a2a.grpc.CancelTaskRequest.newBuilder()
-                .setName("tasks/" + request.id())
+                .setId(request.id())
                 .setTenant(resolveTenant(request.tenant()))
                 .build();
         PayloadAndHeaders payloadAndHeaders = applyInterceptors(CANCEL_TASK_METHOD, cancelTaskRequest, agentCard, context);
@@ -230,13 +230,13 @@ public ListTasksResult listTasks(ListTasksParams request, @Nullable ClientCallCo
 
     @Override
     public TaskPushNotificationConfig createTaskPushNotificationConfiguration(TaskPushNotificationConfig request,
-                                                                              @Nullable ClientCallContext context) throws A2AClientException {
+            @Nullable ClientCallContext context) throws A2AClientException {
         checkNotNullParam("request", request);
 
         String configId = request.pushNotificationConfig().id();
         io.a2a.grpc.CreateTaskPushNotificationConfigRequest grpcRequest = io.a2a.grpc.CreateTaskPushNotificationConfigRequest.newBuilder()
-                .setParent("tasks/" + request.taskId())
-                .setConfig(ToProto.taskPushNotificationConfig(request))
+                .setTaskId(request.taskId())
+                .setConfig(ToProto.taskPushNotificationConfig(request).getPushNotificationConfig())
                 .setConfigId(configId != null ? configId : request.taskId())
                 .setTenant(resolveTenant(request.tenant()))
                 .build();
@@ -251,14 +251,18 @@ public TaskPushNotificationConfig createTaskPushNotificationConfiguration(TaskPu
     }
 
     @Override
-    public TaskPushNotificationConfig getTaskPushNotificationConfiguration(
-            GetTaskPushNotificationConfigParams request,
+    public TaskPushNotificationConfig getTaskPushNotificationConfiguration(GetTaskPushNotificationConfigParams request,
             @Nullable ClientCallContext context) throws A2AClientException {
         checkNotNullParam("request", request);
+        checkNotNullParam("taskId", request.id());
+        if(request.pushNotificationConfigId() == null) {
+             throw new IllegalArgumentException("Id must not be null");
+        }
 
         io.a2a.grpc.GetTaskPushNotificationConfigRequest grpcRequest = io.a2a.grpc.GetTaskPushNotificationConfigRequest.newBuilder()
-                .setName(getTaskPushNotificationConfigName(request))
+                .setTaskId(request.id())
                 .setTenant(resolveTenant(request.tenant()))
+                .setId(request.pushNotificationConfigId())
                 .build();
         PayloadAndHeaders payloadAndHeaders = applyInterceptors(GET_TASK_PUSH_NOTIFICATION_CONFIG_METHOD, grpcRequest, agentCard, context);
 
@@ -277,7 +281,7 @@ public ListTaskPushNotificationConfigResult listTaskPushNotificationConfiguratio
         checkNotNullParam("request", request);
 
         io.a2a.grpc.ListTaskPushNotificationConfigRequest grpcRequest = io.a2a.grpc.ListTaskPushNotificationConfigRequest.newBuilder()
-                .setParent("tasks/" + request.id())
+                .setTaskId(request.id())
                 .setTenant(resolveTenant(request.tenant()))
                 .setPageSize(request.pageSize())
                 .setPageToken(request.pageToken())
@@ -300,7 +304,8 @@ public void deleteTaskPushNotificationConfigurations(DeleteTaskPushNotificationC
         checkNotNullParam("request", request);
 
         io.a2a.grpc.DeleteTaskPushNotificationConfigRequest grpcRequest = io.a2a.grpc.DeleteTaskPushNotificationConfigRequest.newBuilder()
-                .setName(getTaskPushNotificationConfigName(request.id(), request.pushNotificationConfigId()))
+                .setTaskId(request.id())
+                .setId(request.pushNotificationConfigId())
                 .setTenant(resolveTenant(request.tenant()))
                 .build();
         PayloadAndHeaders payloadAndHeaders = applyInterceptors(DELETE_TASK_PUSH_NOTIFICATION_CONFIG_METHOD, grpcRequest, agentCard, context);
@@ -314,14 +319,14 @@ public void deleteTaskPushNotificationConfigurations(DeleteTaskPushNotificationC
     }
 
     @Override
-    public void resubscribe(TaskIdParams request, Consumer<StreamingEventKind> eventConsumer,
+    public void subscribeToTask(TaskIdParams request, Consumer<StreamingEventKind> eventConsumer,
             Consumer<Throwable> errorConsumer, @Nullable ClientCallContext context) throws A2AClientException {
         checkNotNullParam("request", request);
         checkNotNullParam("eventConsumer", eventConsumer);
 
         io.a2a.grpc.SubscribeToTaskRequest grpcRequest = io.a2a.grpc.SubscribeToTaskRequest.newBuilder()
                 .setTenant(resolveTenant(request.tenant()))
-                .setName("tasks/" + request.id())
+                .setId(request.id())
                 .build();
         PayloadAndHeaders payloadAndHeaders = applyInterceptors(SUBSCRIBE_TO_TASK_METHOD, grpcRequest, agentCard, context);
 
@@ -331,12 +336,13 @@ public void resubscribe(TaskIdParams request, Consumer<StreamingEventKind> event
             A2AServiceStub stubWithMetadata = createAsyncStubWithMetadata(context, payloadAndHeaders);
             stubWithMetadata.subscribeToTask(grpcRequest, streamObserver);
         } catch (StatusRuntimeException e) {
-            throw GrpcErrorMapper.mapGrpcError(e, "Failed to resubscribe task push notification config: ");
+            throw GrpcErrorMapper.mapGrpcError(e, "Failed to subscribe task push notification config: ");
         }
     }
 
     /**
      * Ensure tenant is set, using agent default if not provided in request
+     *
      * @param request the initial request.
      * @return the updated request with the tenant set.
      */
@@ -447,24 +453,6 @@ private A2AServiceStub createAsyncStubWithMetadata(@Nullable ClientCallContext c
         return asyncStub.withInterceptors(MetadataUtils.newAttachHeadersInterceptor(metadata));
     }
 
-    private String getTaskPushNotificationConfigName(GetTaskPushNotificationConfigParams params) {
-        return getTaskPushNotificationConfigName(params.id(), params.pushNotificationConfigId());
-    }
-
-    private String getTaskPushNotificationConfigName(String taskId, @Nullable String pushNotificationConfigId) {
-        StringBuilder name = new StringBuilder();
-        name.append("tasks/");
-        name.append(taskId);
-        if (pushNotificationConfigId != null) {
-            name.append("/pushNotificationConfigs/");
-            name.append(pushNotificationConfigId);
-        }
-        //name.append("/pushNotificationConfigs/");
-        // Use taskId as default config ID if none provided
-        //name.append(pushNotificationConfigId != null ? pushNotificationConfigId : taskId);
-        return name.toString();
-    }
-
     private PayloadAndHeaders applyInterceptors(String methodName, Object payload,
             AgentCard agentCard, @Nullable ClientCallContext clientCallContext) {
         PayloadAndHeaders payloadAndHeaders = new PayloadAndHeaders(payload,

client/transport/jsonrpc/src/main/java/io/a2a/client/transport/jsonrpc/JSONRPCTransport.java

@@ -255,7 +255,7 @@ public void deleteTaskPushNotificationConfigurations(DeleteTaskPushNotificationC
     }
 
     @Override
-    public void resubscribe(TaskIdParams request, Consumer<StreamingEventKind> eventConsumer,
+    public void subscribeToTask(TaskIdParams request, Consumer<StreamingEventKind> eventConsumer,
                             Consumer<Throwable> errorConsumer, @Nullable ClientCallContext context) throws A2AClientException {
         checkNotNullParam("request", request);
         checkNotNullParam("eventConsumer", eventConsumer);