a2aproject · kabir · May 6, 2026 · May 6, 2026
diff --git a/...c/src/main/java/org/a2aproject/sdk/compat03/server/apps/quarkus/A2AServerRoutes_v0_3.java b/...c/src/main/java/org/a2aproject/sdk/compat03/server/apps/quarkus/A2AServerRoutes_v0_3.java
@@ -327,7 +327,7 @@ public String getUsername() {
             List<String> extensionHeaderValues = rc.request().headers().getAll(A2AHeaders_v0_3.X_A2A_EXTENSIONS);
             Set<String> requestedExtensions = A2AExtensions.getRequestedExtensions(extensionHeaderValues);
 
-            return new ServerCallContext(user, state, requestedExtensions);
+            return new ServerCallContext(user, state, requestedExtensions, "0.3");
         } else {
             CallContextFactory_v0_3 builder = callContextFactory.get();
             return builder.build(rc);

diff --git a/...rc/main/java/org/a2aproject/sdk/compat03/server/apps/quarkus/CallContextFactory_v0_3.java b/...rc/main/java/org/a2aproject/sdk/compat03/server/apps/quarkus/CallContextFactory_v0_3.java
@@ -3,6 +3,12 @@
 import org.a2aproject.sdk.server.ServerCallContext;
 import io.vertx.ext.web.RoutingContext;
 
+/**
+ * Factory interface for creating ServerCallContext from a Vert.x RoutingContext.
+ *
+ * <p>Implementations MUST pass {@code "0.3"} as the protocol version when constructing
+ * {@link ServerCallContext} so that push notification payloads are formatted correctly.</p>
+ */
 public interface CallContextFactory_v0_3 {
     ServerCallContext build(RoutingContext rc);
 }
diff --git a/...t/src/main/java/org/a2aproject/sdk/compat03/server/rest/quarkus/A2AServerRoutes_v0_3.java b/...t/src/main/java/org/a2aproject/sdk/compat03/server/rest/quarkus/A2AServerRoutes_v0_3.java
@@ -431,7 +431,7 @@ public String getUsername() {
             List<String> extensionHeaderValues = rc.request().headers().getAll(A2AHeaders_v0_3.X_A2A_EXTENSIONS);
             Set<String> requestedExtensions = A2AExtensions.getRequestedExtensions(extensionHeaderValues);
 
-            return new ServerCallContext(user, state, requestedExtensions);
+            return new ServerCallContext(user, state, requestedExtensions, "0.3");
         } else {
             CallContextFactory_v0_3 builder = callContextFactory.get();
             return builder.build(rc);

diff --git a/...rc/main/java/org/a2aproject/sdk/compat03/server/rest/quarkus/CallContextFactory_v0_3.java b/...rc/main/java/org/a2aproject/sdk/compat03/server/rest/quarkus/CallContextFactory_v0_3.java
@@ -3,6 +3,12 @@
 import org.a2aproject.sdk.server.ServerCallContext;
 import io.vertx.ext.web.RoutingContext;
 
+/**
+ * Factory interface for creating ServerCallContext from a Vert.x RoutingContext.
+ *
+ * <p>Implementations MUST pass {@code "0.3"} as the protocol version when constructing
+ * {@link ServerCallContext} so that push notification payloads are formatted correctly.</p>
+ */
 public interface CallContextFactory_v0_3 {
     ServerCallContext build(RoutingContext rc);
 }
diff --git a/...in/java/org/a2aproject/sdk/compat03/conversion/PushNotificationPayloadFormatter_v0_3.java b/...in/java/org/a2aproject/sdk/compat03/conversion/PushNotificationPayloadFormatter_v0_3.java
@@ -0,0 +1,44 @@
+package org.a2aproject.sdk.compat03.conversion;
+
+import jakarta.enterprise.context.ApplicationScoped;
+
+import org.a2aproject.sdk.compat03.conversion.mappers.domain.TaskMapper_v0_3;
+import org.a2aproject.sdk.compat03.json.JsonProcessingException_v0_3;
+import org.a2aproject.sdk.compat03.json.JsonUtil_v0_3;
+import org.a2aproject.sdk.compat03.spec.Task_v0_3;
+import org.a2aproject.sdk.server.tasks.PushNotificationPayloadFormatter;
+import org.a2aproject.sdk.spec.Message;
+import org.a2aproject.sdk.spec.StreamingEventKind;
+import org.a2aproject.sdk.spec.Task;
+import org.jspecify.annotations.Nullable;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@ApplicationScoped
+public class PushNotificationPayloadFormatter_v0_3 implements PushNotificationPayloadFormatter {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(PushNotificationPayloadFormatter_v0_3.class);
+
+    @Override
+    public String targetVersion() {
+        return "0.3";
+    }
+
+    @Override
+    public @Nullable String formatPayload(StreamingEventKind event, @Nullable Task taskSnapshot) {
+        if (event instanceof Message) {
+            return null;
+        }
+        if (taskSnapshot == null) {
+            LOGGER.warn("Cannot format v0.3 push notification: no task snapshot available");
+            return null;
+        }
+        Task_v0_3 v03Task = TaskMapper_v0_3.INSTANCE.fromV10(taskSnapshot);
+        try {
+            return JsonUtil_v0_3.toJson(v03Task);
+        } catch (JsonProcessingException_v0_3 e) {
+            LOGGER.error("Failed to serialize v0.3 task for push notification", e);
+            return null;
+        }
+    }
+}
diff --git a/.../test/java/org/a2aproject/sdk/compat03/conversion/AbstractA2ARequestHandlerTest_v0_3.java b/.../test/java/org/a2aproject/sdk/compat03/conversion/AbstractA2ARequestHandlerTest_v0_3.java
@@ -83,7 +83,7 @@ public abstract class AbstractA2ARequestHandlerTest_v0_3 {
             .parts(new TextPart_v0_3("test message"))
             .build();
 
-    private static final PushNotificationSender NOOP_PUSHNOTIFICATION_SENDER = task -> {};
+    private static final PushNotificationSender NOOP_PUSHNOTIFICATION_SENDER = (event, snapshot) -> {};
 
     // V1.0 backend infrastructure
     protected AgentExecutor agentExecutor;

diff --git a/...va/org/a2aproject/sdk/compat03/conversion/PushNotificationPayloadFormatter_v0_3_Test.java b/...va/org/a2aproject/sdk/compat03/conversion/PushNotificationPayloadFormatter_v0_3_Test.java
@@ -0,0 +1,94 @@
+package org.a2aproject.sdk.compat03.conversion;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.a2aproject.sdk.spec.Message;
+import org.a2aproject.sdk.spec.Task;
+import org.a2aproject.sdk.spec.TaskState;
+import org.a2aproject.sdk.spec.TaskStatus;
+import org.a2aproject.sdk.spec.TaskStatusUpdateEvent;
+import org.a2aproject.sdk.spec.TextPart;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+class PushNotificationPayloadFormatter_v0_3_Test {
+
+    private PushNotificationPayloadFormatter_v0_3 formatter;
+
+    @BeforeEach
+    void setUp() {
+        formatter = new PushNotificationPayloadFormatter_v0_3();
+    }
+
+    @Test
+    void targetVersionIs03() {
+        assertEquals("0.3", formatter.targetVersion());
+    }
+
+    @Test
+    void formatsTaskEventAsV03Task() {
+        Task task = Task.builder()
+                .id("t1").contextId("c1")
+                .status(new TaskStatus(TaskState.TASK_STATE_COMPLETED))
+                .build();
+
+        String payload = formatter.formatPayload(task, task);
+
+        assertNotNull(payload);
+        assertTrue(payload.contains("\"kind\":\"task\""));
+        assertTrue(payload.contains("\"id\":\"t1\""));
+        assertTrue(payload.contains("\"status\""));
+    }
+
+    @Test
+    void formatsStatusUpdateUsingTaskSnapshot() {
+        Task snapshot = Task.builder()
+                .id("t1").contextId("c1")
+                .status(new TaskStatus(TaskState.TASK_STATE_WORKING))
+                .build();
+
+        TaskStatusUpdateEvent event = TaskStatusUpdateEvent.builder()
+                .taskId("t1").contextId("c1")
+                .status(new TaskStatus(TaskState.TASK_STATE_WORKING))
+                .build();
+
+        String payload = formatter.formatPayload(event, snapshot);
+
+        assertNotNull(payload);
+        assertTrue(payload.contains("\"kind\":\"task\""));
+        assertTrue(payload.contains("\"id\":\"t1\""));
+    }
+
+    @Test
+    void skipsMessageEvents() {
+        Task snapshot = Task.builder()
+                .id("t1").contextId("c1")
+                .status(new TaskStatus(TaskState.TASK_STATE_WORKING))
+                .build();
+
+        Message message = Message.builder()
+                .messageId("m1")
+                .role(Message.Role.ROLE_AGENT)
+                .parts(new TextPart("hello"))
+                .build();
+
+        String payload = formatter.formatPayload(message, snapshot);
+
+        assertNull(payload);
+    }
+
+    @Test
+    void returnsNullWhenSnapshotIsNull() {
+        Task task = Task.builder()
+                .id("t1").contextId("c1")
+                .status(new TaskStatus(TaskState.TASK_STATE_COMPLETED))
+                .build();
+
+        String payload = formatter.formatPayload(task, null);
+
+        assertNull(payload);
+    }
+}
diff --git a/...main/java/org/a2aproject/sdk/compat03/transport/grpc/handler/CallContextFactory_v0_3.java b/...main/java/org/a2aproject/sdk/compat03/transport/grpc/handler/CallContextFactory_v0_3.java
@@ -6,6 +6,9 @@
 /**
  * Factory interface for creating ServerCallContext from gRPC StreamObserver.
  * Implementations can provide custom context creation logic.
+ *
+ * <p>Implementations MUST pass {@code "0.3"} as the protocol version when constructing
+ * {@link ServerCallContext} so that push notification payloads are formatted correctly.</p>
  */
 public interface CallContextFactory_v0_3 {
     <V> ServerCallContext create(StreamObserver<V> responseObserver);

diff --git a/...pc/src/main/java/org/a2aproject/sdk/compat03/transport/grpc/handler/GrpcHandler_v0_3.java b/...pc/src/main/java/org/a2aproject/sdk/compat03/transport/grpc/handler/GrpcHandler_v0_3.java
@@ -363,7 +363,7 @@ private <V> ServerCallContext createCallContext(StreamObserver<V> responseObserv
             Map<String, Object> state = new HashMap<>();
             state.put("grpc_response_observer", responseObserver);
             Set<String> requestedExtensions = new HashSet<>();
-            return new ServerCallContext(user, state, requestedExtensions);
+            return new ServerCallContext(user, state, requestedExtensions, "0.3");
         } else {
             return factory.create(responseObserver);
         }

diff --git a/...c/test/java/org/a2aproject/sdk/compat03/transport/grpc/handler/GrpcHandler_v0_3_Test.java b/...c/test/java/org/a2aproject/sdk/compat03/transport/grpc/handler/GrpcHandler_v0_3_Test.java
@@ -65,7 +65,7 @@ public class GrpcHandler_v0_3_Test extends AbstractA2ARequestHandlerTest_v0_3 {
             .build();
 
     private final ServerCallContext callContext = new ServerCallContext(
-            UnauthenticatedUser.INSTANCE, Map.of("foo", "bar"), new HashSet<>());
+            UnauthenticatedUser.INSTANCE, Map.of("foo", "bar"), new HashSet<>(), "0.3");
 
     // ========================================
     // GetTask Tests

diff --git a/.../java/org/a2aproject/sdk/compat03/transport/jsonrpc/handler/JSONRPCHandler_v0_3_Test.java b/.../java/org/a2aproject/sdk/compat03/transport/jsonrpc/handler/JSONRPCHandler_v0_3_Test.java
@@ -85,7 +85,7 @@
 public class JSONRPCHandler_v0_3_Test extends AbstractA2ARequestHandlerTest_v0_3 {
 
     private final ServerCallContext callContext = new ServerCallContext(
-            UnauthenticatedUser.INSTANCE, Map.of("foo", "bar"), new HashSet<>());
+            UnauthenticatedUser.INSTANCE, Map.of("foo", "bar"), new HashSet<>(), "0.3");
 
     // ========================================
     // GetTask Tests

diff --git a/...c/test/java/org/a2aproject/sdk/compat03/transport/rest/handler/RestHandler_v0_3_Test.java b/...c/test/java/org/a2aproject/sdk/compat03/transport/rest/handler/RestHandler_v0_3_Test.java
@@ -32,7 +32,7 @@
 public class RestHandler_v0_3_Test extends AbstractA2ARequestHandlerTest_v0_3 {
 
     private final ServerCallContext callContext = new ServerCallContext(
-            UnauthenticatedUser.INSTANCE, Map.of("foo", "bar"), new HashSet<>());
+            UnauthenticatedUser.INSTANCE, Map.of("foo", "bar"), new HashSet<>(), "0.3");
 
     // ========================================
     // GetTask Tests

diff --git a/...tras/pushnotificationconfigstore/database/jpa/JpaDatabasePushNotificationConfigStore.java b/...tras/pushnotificationconfigstore/database/jpa/JpaDatabasePushNotificationConfigStore.java
@@ -18,6 +18,7 @@
 import org.a2aproject.sdk.util.Assert;
 import org.a2aproject.sdk.util.PageToken;
 import org.a2aproject.sdk.spec.TaskPushNotificationConfig;
+import org.jspecify.annotations.Nullable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -36,6 +37,12 @@ public class JpaDatabasePushNotificationConfigStore implements PushNotificationC
     @Transactional
     @Override
     public TaskPushNotificationConfig setInfo(TaskPushNotificationConfig notificationConfig) {
+        return setInfo(notificationConfig, null);
+    }
+
+    @Transactional
+    @Override
+    public TaskPushNotificationConfig setInfo(TaskPushNotificationConfig notificationConfig, @Nullable String protocolVersion) {
         String taskId = Assert.checkNotNullParam("taskId", notificationConfig.taskId());
         // Ensure config has an ID - default to taskId if not provided (mirroring InMemoryPushNotificationConfigStore behavior)
         if (notificationConfig.id().isEmpty()) {
@@ -44,6 +51,7 @@ public TaskPushNotificationConfig setInfo(TaskPushNotificationConfig notificatio
             notificationConfig = TaskPushNotificationConfig.builder(notificationConfig).id(taskId).build();
         }
 
+        String resolvedVersion = PushNotificationConfigStore.resolveProtocolVersion(protocolVersion);
         LOGGER.debug("Saving PushNotificationConfig for Task '{}' with ID: {}", taskId, notificationConfig.id());
         try {
             TaskConfigId configId = new TaskConfigId(taskId, notificationConfig.id());
@@ -54,11 +62,12 @@ public TaskPushNotificationConfig setInfo(TaskPushNotificationConfig notificatio
             if (existingJpaConfig != null) {
                 // Update existing entity
                 existingJpaConfig.setConfig(notificationConfig);
+                existingJpaConfig.setProtocolVersion(resolvedVersion);
                 LOGGER.debug("Updated existing PushNotificationConfig for Task '{}' with ID: {}",
                         taskId, notificationConfig.id());
             } else {
                 // Create new entity
-                JpaPushNotificationConfig jpaConfig = JpaPushNotificationConfig.createFromConfig(taskId, notificationConfig);
+                JpaPushNotificationConfig jpaConfig = JpaPushNotificationConfig.createFromConfig(taskId, notificationConfig, resolvedVersion);
                 em.persist(jpaConfig);
                 LOGGER.debug("Persisted new PushNotificationConfig for Task '{}' with ID: {}",
                         taskId, notificationConfig.id());
@@ -164,4 +173,27 @@ public void deleteInfo(String taskId, String configId) {
         }
     }
 
+    @Transactional
+    @Override
+    public @Nullable String getProtocolVersion(String taskId, String configId) {
+        JpaPushNotificationConfig jpaConfig = em.find(JpaPushNotificationConfig.class,
+                new TaskConfigId(taskId, configId));
+        return jpaConfig != null ? jpaConfig.getProtocolVersion() : null;
+    }
+
+    @Transactional
+    @Override
+    public java.util.Map<String, String> getProtocolVersions(String taskId) {
+        List<Object[]> results = em.createQuery(
+                "SELECT c.id.configId, c.protocolVersion FROM JpaPushNotificationConfig c " +
+                "WHERE c.id.taskId = :taskId AND c.protocolVersion IS NOT NULL", Object[].class)
+                .setParameter("taskId", taskId)
+                .getResultList();
+        java.util.Map<String, String> versions = new java.util.HashMap<>();
+        for (Object[] row : results) {
+            versions.put((String) row[0], (String) row[1]);
+        }
+        return versions;
+    }
+
 }
diff --git a/...roject/sdk/extras/pushnotificationconfigstore/database/jpa/JpaPushNotificationConfig.java b/...roject/sdk/extras/pushnotificationconfigstore/database/jpa/JpaPushNotificationConfig.java
@@ -10,6 +10,8 @@
 import org.a2aproject.sdk.jsonrpc.common.json.JsonProcessingException;
 import org.a2aproject.sdk.jsonrpc.common.json.JsonUtil;
 import org.a2aproject.sdk.spec.TaskPushNotificationConfig;
+import org.jspecify.annotations.Nullable;
+
 import java.time.Instant;
 
 @Entity
@@ -21,6 +23,9 @@ public class JpaPushNotificationConfig {
     @Column(name = "task_data", columnDefinition = "TEXT", nullable = false)
     private String configJson;
 
+    @Column(name = "protocol_version")
+    private String protocolVersion;
+
     @Column(name = "created_at")
     private Instant createdAt;
 
@@ -79,11 +84,20 @@ public void setCreatedAt(Instant createdAt) {
       this.createdAt = createdAt;
     }
 
-    static JpaPushNotificationConfig createFromConfig(String taskId, TaskPushNotificationConfig config) throws JsonProcessingException {
+    public @Nullable String getProtocolVersion() {
+        return protocolVersion;
+    }
+
+    public void setProtocolVersion(String protocolVersion) {
+        this.protocolVersion = protocolVersion;
+    }
+
+    static JpaPushNotificationConfig createFromConfig(String taskId, TaskPushNotificationConfig config, @Nullable String protocolVersion) throws JsonProcessingException {
         String json = JsonUtil.toJson(config);
         JpaPushNotificationConfig jpaPushNotificationConfig =
                 new JpaPushNotificationConfig(new TaskConfigId(taskId, config.id()), json);
         jpaPushNotificationConfig.config = config;
+        jpaPushNotificationConfig.protocolVersion = protocolVersion;
         return jpaPushNotificationConfig;
     }
 }
diff --git a/...cationconfigstore/database/jpa/JpaDatabasePushNotificationConfigStoreIntegrationTest.java b/...cationconfigstore/database/jpa/JpaDatabasePushNotificationConfigStoreIntegrationTest.java
@@ -91,7 +91,7 @@ public void testDirectNotificationTrigger() {
             .build();
 
         // Directly trigger the mock
-        mockPushNotificationSender.sendNotification(testTask);
+        mockPushNotificationSender.sendNotification(testTask, null);
 
         // Verify it was captured
         Queue<Task> captured = mockPushNotificationSender.getCapturedTasks();

diff --git a/...k/extras/pushnotificationconfigstore/database/jpa/JpaPushNotificationConfigStoreTest.java b/...k/extras/pushnotificationconfigstore/database/jpa/JpaPushNotificationConfigStoreTest.java
@@ -249,7 +249,7 @@ public void testSendNotificationSuccess() throws Exception {
         when(mockPostBuilder.post()).thenReturn(mockHttpResponse);
         when(mockHttpResponse.success()).thenReturn(true);
 
-        notificationSender.sendNotification(task);
+        notificationSender.sendNotification(task, null);
 
         // Verify HTTP client was called
         ArgumentCaptor<String> bodyCaptor = ArgumentCaptor.forClass(String.class);
@@ -281,7 +281,7 @@ public void testSendNotificationWithToken() throws Exception {
         when(mockPostBuilder.post()).thenReturn(mockHttpResponse);
         when(mockHttpResponse.success()).thenReturn(true);
 
-        notificationSender.sendNotification(task);
+        notificationSender.sendNotification(task, null);
 
         // TODO: Once token authentication is implemented, verify that:
         // 1. The token is included in request headers (e.g., X-A2A-Notification-Token)
@@ -307,7 +307,7 @@ public void testSendNotificationNoConfig() throws Exception {
         String taskId = "task_send_no_config";
         Task task = createSampleTask(taskId, TaskState.TASK_STATE_COMPLETED);
 
-        notificationSender.sendNotification(task);
+        notificationSender.sendNotification(task, null);
 
         // Verify HTTP client was never called
         verify(mockHttpClient, never()).createPost();

diff --git a/...oject/sdk/extras/pushnotificationconfigstore/database/jpa/MockPushNotificationSender.java b/...oject/sdk/extras/pushnotificationconfigstore/database/jpa/MockPushNotificationSender.java
@@ -23,7 +23,7 @@ public class MockPushNotificationSender implements PushNotificationSender {
     private final Queue<StreamingEventKind> capturedEvents = new ConcurrentLinkedQueue<>();
 
     @Override
-    public void sendNotification(StreamingEventKind event) {
+    public void sendNotification(StreamingEventKind event, Task taskSnapshot) {
         capturedEvents.add(event);
     }