Enum TaskState 

#[non_exhaustive]
pub enum TaskState {
    Unspecified,
    Submitted,
    Working,
    InputRequired,
    AuthRequired,
    Completed,
    Failed,
    Canceled,
    Rejected,
}

The lifecycle state of a Task.

Per v1.0 spec (Section 5.5), enum values use ProtoJSON SCREAMING_SNAKE_CASE: "TASK_STATE_COMPLETED", "TASK_STATE_INPUT_REQUIRED", etc. Legacy lowercase/kebab-case values are accepted on deserialization.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Unspecified

Proto default (0-value); should not appear in normal usage.

Submitted

Task received, not yet started.

Working

Task is actively being processed.

InputRequired

Agent requires additional input from the client to proceed.

AuthRequired

Agent requires the client to complete an authentication step.

Completed

Task finished successfully.

Failed

Task finished with an error.

Canceled

Task was canceled by the client.

Rejected

Task was rejected by the agent before execution.

Implementations

impl TaskState

pub const fn is_terminal(self) -> bool

Returns true if this state is a terminal (final) state.

Terminal states: Completed, Failed, Canceled, Rejected.

pub const fn is_interrupted(self) -> bool

Returns true if this state is an interrupted state.

Interrupted states: InputRequired, AuthRequired. Per Section 3.2.2, blocking SendMessage MUST return when the task reaches a terminal OR interrupted state.

pub const fn can_transition_to(self, next: TaskState) -> bool

Returns true if transitioning from self to next is a valid state transition per the A2A protocol.

Terminal states cannot transition to any other state. Unspecified can transition to any state.

Trait Implementations

impl Clone for TaskState

fn clone(&self) -> TaskState

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TaskState

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for TaskState

fn deserialize<__D>( __deserializer: __D, ) -> Result<TaskState, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for TaskState

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

Formats the value using the given formatter.

impl Hash for TaskState

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for TaskState

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for TaskState

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Copy for TaskState

impl Eq for TaskState

impl StructuralPartialEq for TaskState