Package org.a2aproject.sdk.client

Class AbstractClient

java.lang.Object
org.a2aproject.sdk.client.AbstractClient
All Implemented Interfaces:
AutoCloseable
Direct Known Subclasses:
Client
public abstract class AbstractClient extends Object implements AutoCloseable
Abstract class representing an A2A client. Provides a standard set of methods for interacting with an A2A agent, regardless of the underlying transport protocol. It supports sending messages, managing tasks, and handling event streams.

  • Field Details

  • Constructor Details

  • Method Details

    • sendMessage

      public void sendMessage(@NonNull Message request) throws A2AClientException
      Send a message to the remote agent. This method will automatically use the streaming or non-streaming approach as determined by the server's agent card and the client configuration. The configured client consumers will be used to handle messages, tasks, and update events received from the remote agent. The configured streaming error handler will be used if an error occurs during streaming. The configured client push notification configuration will get used for streaming.
      Parameters:
      request - the message
      Throws:
      A2AClientException - if sending the message fails for any reason

    • sendMessage

      public void sendMessage(@NonNull Message request, @Nullable ClientCallContext context) throws A2AClientException
      Send a message to the remote agent. This method will automatically use the streaming or non-streaming approach as determined by the server's agent card and the client configuration. The configured client consumers will be used to handle messages, tasks, and update events received from the remote agent. The configured streaming error handler will be used if an error occurs during streaming. The configured client push notification configuration will get used for streaming.
      Parameters:
      request - the message
      context - optional client call context for the request
      Throws:
      A2AClientException - if sending the message fails for any reason

    • sendMessage

      public void sendMessage(@NonNull Message request, @NonNull List<BiConsumer<ClientEvent,AgentCard>> consumers, @Nullable Consumer<Throwable> streamingErrorHandler) throws A2AClientException
      Send a message to the remote agent. This method will automatically use the streaming or non-streaming approach as determined by the server's agent card and the client configuration. The specified client consumers will be used to handle messages, tasks, and update events received from the remote agent. The specified streaming error handler will be used if an error occurs during streaming. The configured client push notification configuration will get used for streaming.
      Parameters:
      request - the message
      consumers - a list of consumers to pass responses from the remote agent to
      streamingErrorHandler - an error handler that should be used for the streaming case if an error occurs
      Throws:
      A2AClientException - if sending the message fails for any reason

    • sendMessage

      public abstract void sendMessage(@NonNull Message request, @NonNull List<BiConsumer<ClientEvent,AgentCard>> consumers, @Nullable Consumer<Throwable> streamingErrorHandler, @Nullable ClientCallContext context) throws A2AClientException
      Send a message to the remote agent. This method will automatically use the streaming or non-streaming approach as determined by the server's agent card and the client configuration. The specified client consumers will be used to handle messages, tasks, and update events received from the remote agent. The specified streaming error handler will be used if an error occurs during streaming. The configured client push notification configuration will get used for streaming.
      Parameters:
      request - the message
      consumers - a list of consumers to pass responses from the remote agent to
      streamingErrorHandler - an error handler that should be used for the streaming case if an error occurs
      context - optional client call context for the request
      Throws:
      A2AClientException - if sending the message fails for any reason

    • sendMessage

      public void sendMessage(@NonNull Message request, @Nullable TaskPushNotificationConfig pushNotificationConfiguration, @Nullable Map<String,Object> metadata) throws A2AClientException
      Send a message to the remote agent. This method will automatically use the streaming or non-streaming approach as determined by the server's agent card and the client configuration. The configured client consumers will be used to handle messages, tasks, and update events received from the remote agent. The configured streaming error handler will be used if an error occurs during streaming.
      Parameters:
      request - the message
      pushNotificationConfiguration - the push notification configuration that should be used if the streaming approach is used
      metadata - the optional metadata to include when sending the message
      Throws:
      A2AClientException - if sending the message fails for any reason

    • sendMessage

      public abstract void sendMessage(@NonNull Message request, @Nullable TaskPushNotificationConfig pushNotificationConfiguration, @Nullable Map<String,Object> metadata, @Nullable ClientCallContext context) throws A2AClientException
      Send a message to the remote agent. This method will automatically use the streaming or non-streaming approach as determined by the server's agent card and the client configuration. The configured client consumers will be used to handle messages, tasks, and update events received from the remote agent. The configured streaming error handler will be used if an error occurs during streaming.
      Parameters:
      request - the message
      pushNotificationConfiguration - the push notification configuration that should be used if the streaming approach is used
      metadata - the optional metadata to include when sending the message
      context - optional client call context for the request
      Throws:
      A2AClientException - if sending the message fails for any reason

    • sendMessage

      public abstract void sendMessage(@NonNull MessageSendParams params, @NonNull List<BiConsumer<ClientEvent,AgentCard>> consumers, @Nullable Consumer<Throwable> streamingErrorHandler, @Nullable ClientCallContext context) throws A2AClientException
      Send a message to the remote agent. This method will automatically use the streaming or non-streaming approach as determined by the server's agent card and the client configuration. The specified client consumers will be used to handle messages, tasks, and update events received from the remote agent. The specified streaming error handler will be used if an error occurs during streaming. The configured client push notification configuration will get used for streaming.
      Parameters:
      params - the request parameters
      consumers - a list of consumers to pass responses from the remote agent to
      streamingErrorHandler - an error handler that should be used for the streaming case if an error occurs
      context - optional client call context for the request
      Throws:
      A2AClientException - if sending the message fails for any reason

    • getTask

      public Task getTask(TaskQueryParams request) throws A2AClientException
      Retrieve the current state and history of a specific task.
      Parameters:
      request - the task query parameters specifying which task to retrieve
      Returns:
      the task
      Throws:
      A2AClientException - if retrieving the task fails for any reason

    • getTask

      public abstract Task getTask(TaskQueryParams request, @Nullable ClientCallContext context) throws A2AClientException
      Retrieve the current state and history of a specific task.
      Parameters:
      request - the task query parameters specifying which task to retrieve
      context - optional client call context for the request (may be null)
      Returns:
      the task
      Throws:
      A2AClientException - if retrieving the task fails for any reason

    • listTasks

      public ListTasksResult listTasks(ListTasksParams request) throws A2AClientException
      List tasks with optional filtering and pagination.
      Parameters:
      request - the list tasks parameters including filters and pagination
      Returns:
      the list tasks result containing tasks and pagination information
      Throws:
      A2AClientException - if listing tasks fails for any reason

    • listTasks

      public abstract ListTasksResult listTasks(ListTasksParams request, @Nullable ClientCallContext context) throws A2AClientException
      List tasks with optional filtering and pagination.
      Parameters:
      request - the list tasks parameters including filters and pagination
      context - optional client call context for the request (may be null)
      Returns:
      the list tasks result containing tasks and pagination information
      Throws:
      A2AClientException - if listing tasks fails for any reason

    • cancelTask

      public Task cancelTask(CancelTaskParams request) throws A2AClientException
      Request the agent to cancel a specific task.
      Parameters:
      request - the task ID parameters specifying which task to cancel
      Returns:
      the cancelled task
      Throws:
      A2AClientException - if cancelling the task fails for any reason

    • cancelTask

      public abstract Task cancelTask(CancelTaskParams request, @Nullable ClientCallContext context) throws A2AClientException
      Request the agent to cancel a specific task.
      Parameters:
      request - the task ID parameters specifying which task to cancel
      context - optional client call context for the request (may be null)
      Returns:
      the cancelled task
      Throws:
      A2AClientException - if cancelling the task fails for any reason

    • createTaskPushNotificationConfiguration

      public TaskPushNotificationConfig createTaskPushNotificationConfiguration(TaskPushNotificationConfig request) throws A2AClientException
      Create or update the push notification configuration for a specific task.
      Parameters:
      request - the push notification configuration to set for the task
      Returns:
      the configured TaskPushNotificationConfig
      Throws:
      A2AClientException - if setting the task push notification configuration fails for any reason

    • createTaskPushNotificationConfiguration

      public abstract TaskPushNotificationConfig createTaskPushNotificationConfiguration(TaskPushNotificationConfig request, @Nullable ClientCallContext context) throws A2AClientException
      Create or update the push notification configuration for a specific task.
      Parameters:
      request - the push notification configuration to set for the task
      context - optional client call context for the request (may be null)
      Returns:
      the configured TaskPushNotificationConfig
      Throws:
      A2AClientException - if setting the task push notification configuration fails for any reason

    • getTaskPushNotificationConfiguration

      public TaskPushNotificationConfig getTaskPushNotificationConfiguration(GetTaskPushNotificationConfigParams request) throws A2AClientException
      Retrieve the push notification configuration for a specific task.
      Parameters:
      request - the parameters specifying which task's notification config to retrieve
      Returns:
      the task push notification config
      Throws:
      A2AClientException - if getting the task push notification config fails for any reason

    • getTaskPushNotificationConfiguration

      public abstract TaskPushNotificationConfig getTaskPushNotificationConfiguration(GetTaskPushNotificationConfigParams request, @Nullable ClientCallContext context) throws A2AClientException
      Retrieve the push notification configuration for a specific task.
      Parameters:
      request - the parameters specifying which task's notification config to retrieve
      context - optional client call context for the request (may be null)
      Returns:
      the task push notification config
      Throws:
      A2AClientException - if getting the task push notification config fails for any reason

    • listTaskPushNotificationConfigurations

      public ListTaskPushNotificationConfigsResult listTaskPushNotificationConfigurations(ListTaskPushNotificationConfigsParams request) throws A2AClientException
      Retrieve the list of push notification configurations for a specific task with pagination support.
      Parameters:
      request - the parameters specifying which task's notification configs to retrieve
      Returns:
      the result containing the list of task push notification configs and pagination information
      Throws:
      A2AClientException - if getting the task push notification configs fails for any reason

    • listTaskPushNotificationConfigurations

      public abstract ListTaskPushNotificationConfigsResult listTaskPushNotificationConfigurations(ListTaskPushNotificationConfigsParams request, @Nullable ClientCallContext context) throws A2AClientException
      Retrieve the list of push notification configurations for a specific task with pagination support.
      Parameters:
      request - the parameters specifying which task's notification configs to retrieve
      context - optional client call context for the request (may be null)
      Returns:
      the result containing the list of task push notification configs and pagination information
      Throws:
      A2AClientException - if getting the task push notification configs fails for any reason

    • deleteTaskPushNotificationConfigurations

      public void deleteTaskPushNotificationConfigurations(DeleteTaskPushNotificationConfigParams request) throws A2AClientException
      Delete the list of push notification configurations for a specific task.
      Parameters:
      request - the parameters specifying which task's notification configs to delete
      Throws:
      A2AClientException - if deleting the task push notification configs fails for any reason

    • deleteTaskPushNotificationConfigurations

      public abstract void deleteTaskPushNotificationConfigurations(DeleteTaskPushNotificationConfigParams request, @Nullable ClientCallContext context) throws A2AClientException
      Delete the list of push notification configurations for a specific task.
      Parameters:
      request - the parameters specifying which task's notification configs to delete
      context - optional client call context for the request (may be null)
      Throws:
      A2AClientException - if deleting the task push notification configs fails for any reason

    • subscribeToTask

      public void subscribeToTask(@NonNull TaskIdParams request) throws A2AClientException
      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 error handler will be used if an error occurs during streaming.
      Parameters:
      request - the parameters specifying which task's notification configs to delete
      Throws:
      A2AClientException - if resubscribing fails for any reason

    • subscribeToTask

      public void subscribeToTask(@NonNull TaskIdParams request, @Nullable ClientCallContext context) throws A2AClientException
      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 error handler will be used if an error occurs during streaming.
      Parameters:
      request - the parameters specifying which task's notification configs to delete
      context - optional client call context for the request
      Throws:
      A2AClientException - if resubscribing fails for any reason

    • subscribeToTask

      public void subscribeToTask(@NonNull TaskIdParams request, @NonNull List<BiConsumer<ClientEvent,AgentCard>> consumers, @Nullable Consumer<Throwable> streamingErrorHandler) throws A2AClientException
      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 handler will be used if an error occurs during streaming.
      Parameters:
      request - the parameters specifying which task's notification configs to delete
      consumers - a list of consumers to pass responses from the remote agent to
      streamingErrorHandler - an error handler that should be used for the streaming case if an error occurs
      Throws:
      A2AClientException - if resubscribing fails for any reason

    • subscribeToTask

      public abstract void subscribeToTask(@NonNull TaskIdParams request, @NonNull List<BiConsumer<ClientEvent,AgentCard>> consumers, @Nullable Consumer<Throwable> streamingErrorHandler, @Nullable ClientCallContext context) throws A2AClientException
      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 handler will be used if an error occurs during streaming.
      Parameters:
      request - the parameters specifying which task's notification configs to delete
      consumers - a list of consumers to pass responses from the remote agent to
      streamingErrorHandler - an error handler that should be used for the streaming case if an error occurs
      context - optional client call context for the request
      Throws:
      A2AClientException - if resubscribing fails for any reason

    • getExtendedAgentCard

      public AgentCard getExtendedAgentCard() throws A2AClientException
      Retrieve the extended AgentCard.
      Returns:
      the extended AgentCard
      Throws:
      A2AClientException - if retrieving the extended agent card fails for any reason

    • getExtendedAgentCard

      public AgentCard getExtendedAgentCard(@Nullable String tenant) throws A2AClientException
      Retrieve the extended AgentCard.
      Parameters:
      tenant - Optional tenant
      Returns:
      the extended AgentCard
      Throws:
      A2AClientException - if retrieving the extended agent card fails for any reason

    • getExtendedAgentCard

      public AgentCard getExtendedAgentCard(@Nullable ClientCallContext context) throws A2AClientException
      Retrieve the extended AgentCard.
      Parameters:
      context - optional client call context for the request (may be null)
      Returns:
      the extended AgentCard
      Throws:
      A2AClientException - if retrieving the extended agent card fails for any reason

    • getExtendedAgentCard

      public abstract AgentCard getExtendedAgentCard(@Nullable String tenant, @Nullable ClientCallContext context) throws A2AClientException
      Retrieve the extended AgentCard.
      Parameters:
      tenant - Optional tenant
      context - optional client call context for the request (may be null)
      Returns:
      the extended AgentCard
      Throws:
      A2AClientException - if retrieving the extended agent card fails for any reason

    • close

      public abstract void close()
      Close the transport and release any associated resources.
      Specified by:
      close in interface AutoCloseable

    • getStreamingErrorHandler

      public @Nullable Consumer<Throwable> getStreamingErrorHandler()
      Get the error handler that should be used during streaming.
      Returns:
      the streaming error handler