Struct Task 

pub struct Task {
    pub id: Arc<str>,
    pub context_id: Option<Arc<str>>,
    pub status: TaskStatus,
    pub artifacts: Vec<Artifact>,
    pub history: Vec<Message>,
    pub metadata: BTreeMap<String, Value>,
}

A unit of work an A2A agent tracks.

Wire form:

{
  "id": "task-123",
  "contextId": "context-456",
  "status": { "state": "working" },
  "artifacts": [...],
  "history": [...],
  "metadata": {...}
}

Fields

id: Arc<str>

The task’s id. Required and unique within the agent.

context_id: Option<Arc<str>>

An optional context id. A context groups related tasks (a multi-turn conversation is a context; each user turn is a task within that context). The spec does not require contexts; an agent that does not support them leaves the field off the wire.

status: TaskStatus

The task’s current status.

artifacts: Vec<Artifact>

The task’s output. An empty list is a task that has not produced any output yet (or a task whose output is empty by design).

history: Vec<Message>

The conversation history that produced the task. A task created from a single SendMessage request has a one-element history; a task created from a streaming interaction has more.

metadata: BTreeMap<String, Value>

Per-task metadata. The spec leaves the shape open; the conventional keys are "trace_id", "session_id", and the custom names a particular deployment uses.

Implementations

impl Task

pub fn new(id: impl Into<Arc<str>>) -> Self

Starts a new task in Submitted state with id. Use with_status to advance the state, with_artifact to attach an output, and so on.

pub fn with_status(self, status: TaskStatus) -> Self

Replaces the task’s status. The task is consumed; chain Task::new(id).with_status(...).with_artifact(...) to build a task in one expression.

pub fn with_artifact(self, artifact: impl Into<Artifact>) -> Self

Appends an artifact to the task.

pub fn with_history_message(self, message: impl Into<Message>) -> Self

Appends a message to the history.

Trait Implementations

impl Clone for Task

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Task

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

Formats the value using the given formatter.

impl Default for Task

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Task

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for Task

impl From<Task> for SendMessageResponse

fn from(task: Task) -> Self

Converts to this type from the input type.

impl From<Task> for GetTaskResponse

fn from(task: Task) -> Self

Converts to this type from the input type.

impl From<Task> for CancelTaskResponse

fn from(task: Task) -> Self

Converts to this type from the input type.

impl PartialEq for Task

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for Task

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Task