fix: Store push notification config for newly created tasks

server-common/src/main/java/io/a2a/server/requesthandlers/DefaultRequestHandler.java

@@ -306,6 +306,14 @@ public EventKind onMessageSend(MessageSendParams params, ServerCallContext conte
             // We do this HERE (not in ResultAggregator) to avoid blocking Vert.x worker threads
             // during the consumption loop itself.
             kind = etai.eventType();
+
+            // Store push notification config for newly created tasks (mirrors streaming logic)
+            // Only for NEW tasks - existing tasks are handled by initMessageSend()
+            if (mss.task() == null && kind instanceof Task createdTask && shouldAddPushInfo(params)) {
+                LOGGER.debug("Storing push notification config for new task {}", createdTask.getId());
+                pushConfigStore.setInfo(createdTask.getId(), params.configuration().pushNotificationConfig());
+            }
+
             if (blocking && interruptedOrNonBlocking) {
                 // For blocking calls: ensure all events are processed before returning
                 // Order of operations is critical to avoid circular dependency:

server-common/src/test/java/io/a2a/server/requesthandlers/DefaultRequestHandlerTest.java

@@ -4,9 +4,11 @@
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
@@ -18,12 +20,14 @@
 import io.a2a.server.auth.UnauthenticatedUser;
 import io.a2a.server.events.EventQueue;
 import io.a2a.server.events.InMemoryQueueManager;
+import io.a2a.server.tasks.InMemoryPushNotificationConfigStore;
 import io.a2a.server.tasks.InMemoryTaskStore;
 import io.a2a.server.tasks.TaskUpdater;
 import io.a2a.spec.JSONRPCError;
 import io.a2a.spec.Message;
 import io.a2a.spec.MessageSendConfiguration;
 import io.a2a.spec.MessageSendParams;
+import io.a2a.spec.PushNotificationConfig;
 import io.a2a.spec.Task;
 import io.a2a.spec.TaskState;
 import io.a2a.spec.TaskStatus;
@@ -794,6 +798,160 @@ void testBlockingCallReturnsCompleteTaskWithArtifacts() throws Exception {
             returnedTask.getArtifacts().size());
     }
 
+    /**
+     * Test that pushNotificationConfig from SendMessageConfiguration is stored for NEW tasks
+     * in non-streaming (blocking) mode. This reproduces the bug from issue #84.
+     *
+     * Expected behavior:
+     * 1. Client sends message with pushNotificationConfig in SendMessageConfiguration
+     * 2. Agent creates a new task
+     * 3. pushNotificationConfig should be stored in PushNotificationConfigStore
+     * 4. Config should be retrievable via getInfo()
+     */
+    @Test
+    @Timeout(10)
+    void testBlockingMessageStoresPushNotificationConfigForNewTask() throws Exception {
+        String taskId = "push-config-blocking-new-task";
+        String contextId = "push-config-ctx";
+
+        // Create test config store
+        InMemoryPushNotificationConfigStore pushConfigStore = new InMemoryPushNotificationConfigStore();
+
+        // Re-create request handler with pushConfigStore
+        requestHandler = DefaultRequestHandler.create(
+            agentExecutor,
+            taskStore,
+            queueManager,
+            pushConfigStore, // Add push config store
+            null, // pushSender
+            Executors.newCachedThreadPool()
+        );
+
+        // Create push notification config
+        PushNotificationConfig pushConfig = new PushNotificationConfig.Builder()
+            .id("config-1")
+            .url("https://example.com/webhook")
+            .token("test-token-123")
+            .build();
+
+        // Create message with pushNotificationConfig
+        Message message = new Message.Builder()
+            .messageId("msg-push-config")
+            .role(Message.Role.USER)
+            .parts(new TextPart("test message"))
+            .taskId(taskId)
+            .contextId(contextId)
+            .build();
+
+        MessageSendConfiguration config = new MessageSendConfiguration.Builder()
+            .blocking(true)
+            .pushNotificationConfig(pushConfig)
+            .build();
+
+        MessageSendParams params = new MessageSendParams(message, config, null);
+
+        // Agent creates a new task
+        agentExecutor.setExecuteCallback((context, queue) -> {
+            TaskUpdater updater = new TaskUpdater(context, queue);
+            updater.submit();  // Creates new task in SUBMITTED state
+            updater.complete();
+        });
+
+        // Call blocking onMessageSend
+        Object result = requestHandler.onMessageSend(params, serverCallContext);
+
+        // Verify result is a task
+        assertTrue(result instanceof Task, "Result should be a Task");
+        Task returnedTask = (Task) result;
+        assertEquals(taskId, returnedTask.getId());
+
+        // THE KEY ASSERTION: Verify pushNotificationConfig was stored
+        List<PushNotificationConfig> storedConfigs = pushConfigStore.getInfo(taskId);
+        assertNotNull(storedConfigs, "Push notification config should be stored for new task");
+        assertEquals(1, storedConfigs.size(),
+            "Should have exactly 1 push config stored");
+        assertEquals("config-1", storedConfigs.get(0).id());
+        assertEquals("https://example.com/webhook", storedConfigs.get(0).url());
+    }
+
+    /**
+     * Test that pushNotificationConfig is stored for EXISTING tasks.
+     * This verifies the initMessageSend logic works correctly.
+     */
+    @Test
+    @Timeout(10)
+    void testMessageStoresPushNotificationConfigForExistingTask() throws Exception {
+        String taskId = "push-config-existing-task";
+        String contextId = "push-config-existing-ctx";
+
+        // Create test config store
+        InMemoryPushNotificationConfigStore pushConfigStore = new InMemoryPushNotificationConfigStore();
+
+        // Re-create request handler with pushConfigStore
+        requestHandler = DefaultRequestHandler.create(
+            agentExecutor,
+            taskStore,
+            queueManager,
+            pushConfigStore, // Add push config store
+            null, // pushSender
+            Executors.newCachedThreadPool()
+        );
+
+        // Create EXISTING task in store
+        Task existingTask = new Task.Builder()
+            .id(taskId)
+            .contextId(contextId)
+            .status(new TaskStatus(TaskState.WORKING))
+            .build();
+        taskStore.save(existingTask);
+
+        // Create push notification config
+        PushNotificationConfig pushConfig = new PushNotificationConfig.Builder()
+            .id("config-existing-1")
+            .url("https://example.com/existing-webhook")
+            .token("existing-token-789")
+            .build();
+
+        Message message = new Message.Builder()
+            .messageId("msg-push-existing")
+            .role(Message.Role.USER)
+            .parts(new TextPart("update existing task"))
+            .taskId(taskId)
+            .contextId(contextId)
+            .build();
+
+        MessageSendConfiguration config = new MessageSendConfiguration.Builder()
+            .blocking(true)
+            .pushNotificationConfig(pushConfig)
+            .build();
+
+        MessageSendParams params = new MessageSendParams(message, config, null);
+
+        // Agent updates the existing task
+        agentExecutor.setExecuteCallback((context, queue) -> {
+            TaskUpdater updater = new TaskUpdater(context, queue);
+            updater.addArtifact(
+                List.of(new TextPart("update artifact", null)),
+                "artifact-1", "Update", null);
+            updater.complete();
+        });
+
+        // Call blocking onMessageSend
+        Object result = requestHandler.onMessageSend(params, serverCallContext);
+
+        // Verify result
+        assertTrue(result instanceof Task, "Result should be a Task");
+
+        // Verify pushNotificationConfig was stored (initMessageSend path)
+        List<PushNotificationConfig> storedConfigs = pushConfigStore.getInfo(taskId);
+        assertNotNull(storedConfigs,
+            "Push notification config should be stored for existing task");
+        assertEquals(1, storedConfigs.size(),
+            "Should have exactly 1 push config stored");
+        assertEquals("config-existing-1", storedConfigs.get(0).id());
+        assertEquals("https://example.com/existing-webhook", storedConfigs.get(0).url());
+    }
+
     /**
      * Simple test agent executor that allows controlling execution timing
      */