Struct Task 

pub struct Task {
    pub id: TaskId,
    pub thread_id: String,
    pub status: TaskStatus,
    pub message: Message,
    pub messages: Vec<Message>,
    pub artifacts: Vec<Artifact>,
    pub created_at: DateTime<Utc>,
    pub updated_at: DateTime<Utc>,
    pub error: Option<String>,
    pub metadata: Option<Value>,
}

A task in the A2A protocol.

Tasks are the primary unit of work in A2A. They are submitted by clients and processed by agents.

Fields

id: TaskId

Unique identifier for this task.

thread_id: String

Thread ID for grouping related tasks.

status: TaskStatus

Current status of the task.

message: Message

The original message that created this task.

messages: Vec<Message>

Messages in the conversation.

artifacts: Vec<Artifact>

Artifacts produced by the task.

created_at: DateTime<Utc>

When the task was created.

updated_at: DateTime<Utc>

When the task was last updated.

error: Option<String>

Optional error message if the task failed.

metadata: Option<Value>

Optional metadata.

Implementations

impl Task

pub fn new(thread_id: impl Into<String>, message: Message) -> Self

Create a new task.

The original message is automatically added to the messages list.

pub fn with_id( id: impl Into<String>, thread_id: impl Into<String>, message: Message, ) -> Self

Create a new task with a specific ID.

The original message is automatically added to the messages list.

pub fn is_pending(&self) -> bool

Check if the task is pending.

pub fn is_running(&self) -> bool

Check if the task is running.

pub fn is_completed(&self) -> bool

Check if the task is completed (success or failure).

pub fn is_success(&self) -> bool

Check if the task succeeded.

pub fn is_failed(&self) -> bool

Check if the task failed.

pub fn start(&mut self) -> Result<(), TaskError>

Mark the task as running.

Errors

Returns TaskError::InvalidStateTransition if the task is not pending.

pub fn complete(&mut self) -> Result<(), TaskError>

Mark the task as completed.

Errors

Returns TaskError::InvalidStateTransition if the task is not running.

pub fn fail(&mut self, error: impl Into<String>) -> Result<(), TaskError>

Mark the task as failed.

Errors

Returns TaskError::InvalidStateTransition if the task is not running.

pub fn cancel(&mut self) -> Result<(), TaskError>

Mark the task as cancelled.

Cancellation is allowed from pending or running states.

Errors

Returns TaskError::InvalidStateTransition if the task is already completed.

pub fn force_status(&mut self, status: TaskStatus)

Force set status without validation (for internal/recovery use).

Use with caution - this bypasses state transition validation.

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.

pub fn set_metadata(&mut self, metadata: Value)

Set metadata on 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<'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 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.