Package io.a2a.server.tasks

Interface PushNotificationConfigStore

All Known Implementing Classes:
InMemoryPushNotificationConfigStore
public interface PushNotificationConfigStore
Interface for storing and retrieving push notification configurations for tasks.

Push notification configurations specify where and how to deliver task state updates to external systems (webhook URLs, authentication headers, etc.). A task can have multiple push notification configurations for different endpoints or use cases.

Configuration ID Semantics

Each push notification config has an ID:
  • If not provided in PushNotificationConfig, defaults to the task ID
  • Multiple configs per task require unique IDs (e.g., "webhook-1", "webhook-2")
  • Used for retrieval and deletion of specific configurations

Pagination Support

getInfo(ListTaskPushNotificationConfigParams) supports pagination for tasks with many push notification configurations:
  • pageSize: Maximum number of configs to return (0 = unlimited)
  • pageToken: Continuation token from previous response
  • Returns ListTaskPushNotificationConfigResult with configs and next page token

Default Implementation

InMemoryPushNotificationConfigStore:
  • Stores configs in ConcurrentHashMap
  • Thread-safe for concurrent operations
  • Configs lost on application restart

Alternative Implementations

  • extras/push-notification-config-store-database-jpa: Database persistence with JPA
Database implementations survive restarts and enable config sharing across server instances.

CDI Extension Pattern


 @ApplicationScoped
 @Alternative
 @Priority(50)
 public class JpaDatabasePushNotificationConfigStore implements PushNotificationConfigStore {
     @PersistenceContext
     EntityManager em;

     @Transactional
     public PushNotificationConfig setInfo(String taskId, PushNotificationConfig config) {
         // JPA persistence logic
     }
 }

Thread Safety

Implementations must be thread-safe. Multiple threads may call methods concurrently for the same or different tasks.
See Also:

  • Method Details

    • setInfo

      PushNotificationConfig setInfo(String taskId, PushNotificationConfig notificationConfig)
      Sets or updates the push notification configuration for a task.

      If notificationConfig.id() is null or empty, it's set to the task ID. If a config with the same ID already exists for this task, it's replaced.

      Parameters:
      taskId - the task ID
      notificationConfig - the push notification configuration
      Returns:
      the potentially updated configuration (with ID set if it was null)

    • getInfo

      ListTaskPushNotificationConfigResult getInfo(ListTaskPushNotificationConfigParams params)
      Retrieves push notification configurations for a task with pagination support.

      Returns all configs if params.pageSize() is 0. Otherwise, returns up to pageSize configs and a continuation token for the next page.

      Pagination Example: 

      
 // First page
 ListTaskPushNotificationConfigParams params =
     new ListTaskPushNotificationConfigParams(taskId, 10, null, tenant);
 ListTaskPushNotificationConfigResult result = store.getInfo(params);

 // Next page
 if (result.nextPageToken() != null) {
     params = new ListTaskPushNotificationConfigParams(
         taskId, 10, result.nextPageToken(), tenant);
     result = store.getInfo(params);
 }
      Parameters:
      params - the query parameters including task ID, page size, and page token
      Returns:
      the configurations for this task (empty list if none found)

    • deleteInfo

      void deleteInfo(String taskId, String configId)
      Deletes a push notification configuration for a task.

      If configId is null, it defaults to the task ID (deletes the default config). If no config exists with the given ID, this method returns normally (idempotent).

      Parameters:
      taskId - the task ID
      configId - the push notification configuration ID (null = use task ID)