Struct RequestHandler 

pub struct RequestHandler { /* private fields */ }

The core protocol logic handler.

Orchestrates task lifecycle, event streaming, push notifications, and interceptor chains for all A2A methods.

RequestHandler is not generic — it stores the executor as Arc<dyn AgentExecutor>, enabling dynamic dispatch and simplifying the downstream API (dispatchers, builder, etc.).

Store ownership

Stores are held as Arc<dyn TaskStore> / Arc<dyn PushConfigStore> rather than Box<dyn ...> so that they can be cheaply cloned into background tasks (e.g. the streaming push-delivery processor).

Implementations

impl RequestHandler

pub async fn on_cancel_task( &self, params: CancelTaskParams, headers: Option<&HashMap<String, String>>, ) -> Result<Task, ServerError>

Handles CancelTask.

Errors

Returns ServerError::TaskNotFound or ServerError::TaskNotCancelable.

impl RequestHandler

pub async fn on_get_extended_agent_card( &self, headers: Option<&HashMap<String, String>>, ) -> Result<AgentCard, ServerError>

Handles GetExtendedAgentCard.

Errors

Returns ServerError::Internal if no agent card is configured.

impl RequestHandler

pub async fn on_get_task( &self, params: TaskQueryParams, headers: Option<&HashMap<String, String>>, ) -> Result<Task, ServerError>

Handles GetTask. Returns ServerError::TaskNotFound if missing.

Errors

Returns ServerError::TaskNotFound if the task does not exist.

impl RequestHandler

pub async fn on_list_tasks( &self, params: ListTasksParams, headers: Option<&HashMap<String, String>>, ) -> Result<TaskListResponse, ServerError>

Handles ListTasks.

Errors

Returns a ServerError if the store query fails.

impl RequestHandler

pub async fn on_resubscribe( &self, params: TaskIdParams, headers: Option<&HashMap<String, String>>, ) -> Result<InMemoryQueueReader, ServerError>

Handles SubscribeToTask.

Errors

Returns ServerError::TaskNotFound if the task does not exist.

impl RequestHandler

pub async fn on_send_message( &self, params: MessageSendParams, streaming: bool, headers: Option<&HashMap<String, String>>, ) -> Result<SendMessageResult, ServerError>

Handles SendMessage / SendStreamingMessage.

The optional headers map carries HTTP request headers for interceptor access-control decisions (e.g. Authorization).

Errors

Returns ServerError if task creation or execution fails.

impl RequestHandler

pub async fn on_set_push_config( &self, config: TaskPushNotificationConfig, headers: Option<&HashMap<String, String>>, ) -> Result<TaskPushNotificationConfig, ServerError>

Handles CreateTaskPushNotificationConfig.

Errors

Returns ServerError::PushNotSupported if no push sender is configured.

pub async fn on_get_push_config( &self, params: GetPushConfigParams, headers: Option<&HashMap<String, String>>, ) -> Result<TaskPushNotificationConfig, ServerError>

Handles GetTaskPushNotificationConfig.

Errors

Returns ServerError::InvalidParams if the config is not found.

pub async fn on_list_push_configs( &self, task_id: &str, tenant: Option<&str>, headers: Option<&HashMap<String, String>>, ) -> Result<Vec<TaskPushNotificationConfig>, ServerError>

Handles ListTaskPushNotificationConfigs.

Errors

Returns a ServerError if the store query fails.

pub async fn on_delete_push_config( &self, params: DeletePushConfigParams, headers: Option<&HashMap<String, String>>, ) -> Result<(), ServerError>

Handles DeleteTaskPushNotificationConfig.

Errors

Returns a ServerError if the delete operation fails.

impl RequestHandler

pub async fn shutdown(&self)

Initiates graceful shutdown of the handler.

This method:

1. Cancels all in-flight tasks by signalling their cancellation tokens.
2. Destroys all event queues, causing readers to see EOF.

After calling shutdown(), new requests will still be accepted but in-flight tasks will observe cancellation. The caller should stop accepting new connections after calling this method.

pub async fn shutdown_with_timeout(&self, timeout: Duration)

Initiates graceful shutdown with a timeout.

Cancels all in-flight tasks and waits up to timeout for event queues to drain before force-destroying them. This gives executors a chance to finish writing final events before the queues are torn down.

impl RequestHandler

pub fn tenant_resolver(&self) -> Option<&(dyn TenantResolver + 'static)>

Returns the tenant resolver, if configured.

Use this in dispatchers or middleware to resolve the tenant identity from a CallContext before processing a request.

pub const fn tenant_config(&self) -> Option<&PerTenantConfig>

Returns the per-tenant configuration, if configured.

Use this alongside tenant_resolver to look up resource limits for the resolved tenant.

Trait Implementations

impl Debug for RequestHandler

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.