Enum StopReason 

#[non_exhaustive]
pub enum StopReason {
    EndTurn,
    MaxTokens,
    MaxTurnRequests,
    Refusal,
    Cancelled,
}

Reasons why an agent stops processing a prompt turn.

See protocol docs: Stop Reasons

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.

EndTurn

The turn ended successfully.

MaxTokens

The turn ended because the agent reached the maximum number of tokens.

MaxTurnRequests

The turn ended because the agent reached the maximum number of allowed agent requests between user turns.

Refusal

The turn ended because the agent refused to continue. The user prompt and everything that comes after it won’t be included in the next prompt, so this should be reflected in the UI.

Cancelled

The turn was cancelled by the client via session/cancel.

This stop reason MUST be returned when the client sends a session/cancel notification, even if the cancellation causes exceptions in underlying operations. Agents should catch these exceptions and return this semantically meaningful response to confirm successful cancellation.

Trait Implementations

impl Clone for StopReason

fn clone(&self) -> StopReason

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for StopReason

impl Debug for StopReason

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for StopReason

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for StopReason

impl IntoV2 for StopReason

Available on crate feature unstable_protocol_v2 only.

type Output = StopReason

The corresponding v2 draft type.

fn into_v2(self) -> Result<Self::Output>

Converts this value into the corresponding v2 draft type.

impl JsonSchema for StopReason

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

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 inline_schema() -> bool

Whether JSON Schemas generated for this type should be included directly in parent schemas, rather than being re-used where possible using the $ref keyword.

impl PartialEq for StopReason

fn eq(&self, other: &StopReason) -> 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 StopReason

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 StopReason