Struct Task 

pub struct Task {
    pub id: String,
    pub context_id: Option<String>,
    pub state: TaskState,
    pub messages: Vec<Message>,
    pub artifacts: Vec<Artifact>,
    pub metadata: Option<Value>,
    pub created_at: Option<DateTime<Utc>>,
    pub updated_at: Option<DateTime<Utc>>,
}

A Task — the fundamental unit of work in A2A.

Fields

id: String

Unique identifier for this task.

context_id: Option<String>

Optional context ID grouping related tasks for session coherence.

state: TaskState

Current state of the task.

messages: Vec<Message>

Messages exchanged during the task (multi-turn conversation).

artifacts: Vec<Artifact>

Artifacts produced by the task.

metadata: Option<Value>

Optional metadata attached to the task.

created_at: Option<DateTime<Utc>>

When the task was created.

updated_at: Option<DateTime<Utc>>

When the task was last updated.

Implementations

impl Task

pub fn new() -> Self

Create a new task with a generated ID.

pub fn with_context(context_id: impl Into<String>) -> Self

Create a new task within a context (session).

pub fn is_terminal(&self) -> bool

Check if the task is in a terminal state.

pub fn is_interrupted(&self) -> bool

Check if the task is in an interrupted state (needs input or auth).

pub fn transition( &mut self, new_state: TaskState, ) -> Result<(), InvalidTransition>

Transition the task to a new state.

pub fn add_message(&mut self, message: Message)

Add a message to the task.

pub fn add_artifact(&mut self, artifact: Artifact)

Add an artifact to the task.

Trait Implementations

impl Clone for Task

fn clone(&self) -> Task

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 JsonSchema for Task

fn schema_name() -> String

The name of the generated JSON Schema.

fn schema_id() -> Cow<'static, str>

Returns a string that uniquely identifies the schema produced by this type.

fn json_schema(generator: &mut SchemaGenerator) -> Schema

Generates a JSON Schema for this type.

fn is_referenceable() -> bool

Whether JSON Schemas generated for this type should be re-used where possible using the $ref keyword.

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.