Struct RequestHandler 

pub struct RequestHandler { /* private fields */ }

Available on crate features a2a-v1 and server only.

Shared dispatch layer for A2A v1.0.0 operations.

Maps operation names to executor/store calls. Used by both the JSON-RPC handler and the REST handler.

When constructed with a adk_runner::RunnerConfig via RequestHandler::with_runner, message_send and message_stream invoke the agent through the ADK Runner for real LLM generation. Without a runner config, they perform state transitions only (useful for protocol-level testing).

The operation methods on RequestHandler act for an unauthenticated caller. Use for_caller to act for an authenticated one; the bundled transports do this with the principal from the request extensions.

Implementations

impl RequestHandler

pub fn new( executor: Arc<V1Executor>, task_store: Arc<dyn TaskStore>, push_sender: Arc<dyn PushNotificationSender>, agent_card: Arc<RwLock<CachedAgentCard>>, ) -> RequestHandler

Creates a new request handler without a runner (stub mode).

pub fn with_runner( executor: Arc<V1Executor>, task_store: Arc<dyn TaskStore>, push_sender: Arc<dyn PushNotificationSender>, agent_card: Arc<RwLock<CachedAgentCard>>, runner_config: Arc<RunnerConfig>, ) -> RequestHandler

Creates a new request handler with a runner for real LLM invocation.

pub fn for_caller(&self, caller: Option<RequestContext>) -> CallerScope<'_>

Returns a view of this handler that acts on behalf of caller.

With Some(caller), the agent session belongs to caller.user_id, every created task is owned by that user, and operations on tasks owned by anyone else fail with A2aError::TaskNotFound. With None — no authentication configured — the session user is a2a-{contextId} and only ownerless tasks are visible.

Example

let task = handler.for_caller(Some(request_context)).message_send(msg).await?;

pub async fn message_send(&self, msg: Message) -> Result<Task, A2aError>

Sends a message as an unauthenticated caller; see CallerScope::message_send.

Errors

See CallerScope::message_send.

pub async fn message_stream( &self, msg: Message, ) -> Result<Pin<Box<dyn Stream<Item = Result<StreamResponse, A2aError>> + Send>>, A2aError>

Sends a streaming message as an unauthenticated caller; see CallerScope::message_stream.

Errors

See CallerScope::message_stream.

pub async fn tasks_get( &self, task_id: &str, history_len: Option<u32>, ) -> Result<Task, A2aError>

Retrieves an ownerless task; see CallerScope::tasks_get.

Errors

Returns A2aError::TaskNotFound if the task does not exist or has an owner.

pub async fn tasks_cancel(&self, task_id: &str) -> Result<Task, A2aError>

Cancels an ownerless task; see CallerScope::tasks_cancel.

Errors

See CallerScope::tasks_cancel.

pub async fn tasks_list( &self, params: ListTasksParams, ) -> Result<Vec<Task>, A2aError>

Lists ownerless tasks; see CallerScope::tasks_list.

Errors

Returns an error if the task store fails.

pub async fn tasks_subscribe( &self, task_id: &str, ) -> Result<Pin<Box<dyn Stream<Item = Result<StreamResponse, A2aError>> + Send>>, A2aError>

Snapshots an ownerless task; see CallerScope::tasks_subscribe.

Errors

See CallerScope::tasks_subscribe.

pub async fn push_config_create( &self, task_id: &str, config: TaskPushNotificationConfig, ) -> Result<TaskPushNotificationConfig, A2aError>

Creates a push notification configuration on an ownerless task; see CallerScope::push_config_create.

Errors

Returns A2aError::TaskNotFound if the task does not exist or has an owner.

pub async fn push_config_get( &self, task_id: &str, config_id: &str, ) -> Result<TaskPushNotificationConfig, A2aError>

Retrieves a push notification configuration from an ownerless task; see CallerScope::push_config_get.

Errors

Returns A2aError::TaskNotFound if the task or config does not exist.

pub async fn push_config_list( &self, task_id: &str, ) -> Result<Vec<TaskPushNotificationConfig>, A2aError>

Lists the push notification configurations of an ownerless task; see CallerScope::push_config_list.

Errors

Returns A2aError::TaskNotFound if the task does not exist or has an owner.

pub async fn push_config_delete( &self, task_id: &str, config_id: &str, ) -> Result<(), A2aError>

Deletes a push notification configuration from an ownerless task; see CallerScope::push_config_delete.

Errors

Returns A2aError::TaskNotFound if the task or config does not exist.

pub async fn agent_card_extended(&self) -> Result<AgentCard, A2aError>

Returns the extended agent card.

Errors

Returns A2aError::ExtendedAgentCardNotConfigured if no card is set.

pub fn executor(&self) -> &Arc<V1Executor>

Returns a reference to the underlying executor.

pub fn task_store(&self) -> &Arc<dyn TaskStore>

Returns a reference to the underlying task store.