Struct TaskManager 

pub struct TaskManager { /* private fields */ }

Available on crate features mcp and server and tools only.

Server-side task store and executor for the SEP-2663 Tasks extension.

Cheaply cloneable; all clones share the same state.

Retention

Entries are swept opportunistically on every spawn / get_task / update_task / cancel_task / running_task_count call: non-terminal tasks whose ttl_ms has elapsed are marked failed (their operation is aborted), and terminal tasks are evicted after being retained for one further ttl_ms window past their terminal transition so pollers can observe the final state.

Note that the retention window intentionally extends past the creation-based lifetime that ttl_ms advertises on the wire: a task that runs to its TTL deadline is marked failed around created + ttl_ms and stays observable until roughly created + 2 × ttl_ms. This is compliant — SEP-2663 lets servers delete expired tasks at any time after the TTL, so retaining them longer as an observation grace period is a server-side policy choice, not a wire-contract change. Clients may treat the task as unusable after createdAt + ttlMs regardless.

Tasks with ttl_ms: None are retained for the lifetime of the manager (spec: unlimited retention) — bound task creation or call Self::shutdown yourself if you spawn such tasks in a long-lived server. There is no background sweeper; an idle manager holds its entries until the next call.

Implementations

impl TaskManager

pub fn new() -> TaskManager

pub fn spawn<F>(&self, options: TaskOptions, make_future: F) -> Task

where F: FnOnce(TaskContext) -> Pin<Box<dyn Future<Output = Result<CallToolResult, TaskExit>> + Send>>,

Spawn an operation as a task and return its seed Task state for a CreateTaskResult. The task is durably observable via Self::get_task before this method returns.

make_future receives a TaskContext for mid-task input requests, status messages, and cooperative cancellation checks.

pub fn get_task(&self, task_id: &str) -> Result<DetailedTask, ErrorData>

Handle tasks/get: return the current DetailedTask state.

pub fn update_task( &self, task_id: &str, input_responses: impl IntoIterator<Item = (String, Value)>, ) -> Result<(), ErrorData>

Handle tasks/update: deliver inputResponses to the running operation. Unknown, already-answered, or superseded keys are ignored per spec; a partial set of responses is accepted.

pub fn cancel_task(&self, task_id: &str) -> Result<(), ErrorData>

Handle tasks/cancel: cooperative cancellation (SEP-2663).

Records the cancellation intent and acknowledges immediately, but does not abort the underlying future or force a terminal state. The operation observes cancellation via TaskContext::is_cancel_requested / TaskContext::cancelled, or via the error returned from a pending TaskContext::request_input call (whose response channel is dropped here), and decides its own terminal status:

• stops with TaskExit::Cancelled → recorded as cancelled,
• stops with TaskExit::Error → recorded as failed with the error inlined (a real failure after a cancel request is not masked),
• finishes its work anyway → recorded as completed — per the spec, “the task may still reach a non-cancelled terminal status”.

pub fn running_task_count(&self) -> usize

Number of tasks currently in a non-terminal state.

pub fn shutdown(&self)

Abort all running tasks and clear all task state.

Trait Implementations

impl Clone for TaskManager

fn clone(&self) -> TaskManager

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Default for TaskManager

fn default() -> TaskManager

Returns the “default value” for a type.