Enum Event 

#[non_exhaustive]
pub enum Event {
    TurnBegin {
        user_input: UserInput,
    },
    TurnEnd,
    StepBegin {
        n: u32,
    },
    StepInterrupted,
    StepRetry {
        n: u32,
        next_attempt: u32,
        max_attempts: u32,
        wait_s: u32,
        error_type: String,
        status_code: Option<u32>,
    },
    CompactionBegin,
    CompactionEnd,
    StatusUpdate(StatusUpdate),
    ContentPart(ContentPart),
    ToolCall {
        id: String,
        function: ToolCallFunction,
        extras: Option<Value>,
    },
    ToolCallPart {
        arguments_part: Option<String>,
    },
    ToolResult {
        tool_call_id: String,
        return_value: ToolReturnValue,
    },
    ApprovalResponse {
        request_id: String,
        response: ApprovalResponseKind,
        feedback: Option<String>,
    },
    SubagentEvent {
        parent_tool_call_id: Option<String>,
        agent_id: Option<String>,
        subagent_type: Option<String>,
        event: SubagentEventPayload,
    },
    SteerInput {
        user_input: UserInput,
    },
    BtwBegin {
        id: String,
        question: String,
    },
    BtwEnd {
        id: String,
        response: Option<String>,
        error: Option<String>,
    },
    PlanDisplay {
        content: String,
        file_path: String,
    },
    HookTriggered {
        event: String,
        target: String,
        hook_count: u32,
    },
    HookResolved {
        event: String,
        target: String,
        action: HookAction,
        reason: String,
        duration_ms: u64,
    },
}

An event emitted by the agent during a turn.

Events are sent as JSON-RPC notifications (method: "event") and do not require a response.

Serialization follows the official wire envelope format: {"type": "TurnBegin", "payload": {"user_input": ...}}.

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.

TurnBegin

A new turn has started with the given user input.

Fields

user_input: UserInput

The user’s input that triggered this turn.

TurnEnd

The current turn has ended.

StepBegin

A new step within the turn has started.

Fields

n: u32

Step number, starting from 1.

StepInterrupted

The current step was interrupted (e.g. by user input).

StepRetry

The current step attempt failed and will be retried.

Added in Wire protocol v1.10.

Fields

n: u32

Step number.

next_attempt: u32

Next attempt number, 1-based.

max_attempts: u32

Maximum number of attempts for this step.

wait_s: u32

Seconds to wait before retrying.

error_type: String

Exception class name that triggered the retry.

status_code: Option<u32>

HTTP status code (if available).

CompactionBegin

Context compaction has started.

CompactionEnd

Context compaction has finished.

StatusUpdate(StatusUpdate)

Server status update (token usage, context size, etc.).

ContentPart(ContentPart)

A content part (text, image, etc.) from the model.

ToolCall

A tool call from the model.

Wire envelope type is "ToolCall". The payload carries an inner type: "function" discriminator, matching the official v1.10 spec.

Fields

id: String

Tool call id.

function: ToolCallFunction

Function name and arguments.

extras: Option<Value>

Extra fields from the wire protocol.

ToolCallPart

A partial tool call (streaming arguments).

Fields

arguments_part: Option<String>

Partial JSON arguments.

ToolResult

Result of a tool execution.

Fields

tool_call_id: String

Id of the corresponding tool call.

return_value: ToolReturnValue

Return value from the tool.

ApprovalResponse

Response to an approval request (sent by the client).

Fields

request_id: String

Id of the approval request.

response: ApprovalResponseKind

Approval decision.

feedback: Option<String>

Optional feedback text from the user.

SubagentEvent

An event from a subagent.

Fields

parent_tool_call_id: Option<String>

Id of the parent tool call that spawned the subagent.

agent_id: Option<String>

Subagent id.

subagent_type: Option<String>

Subagent type.

event: SubagentEventPayload

Nested wire message in envelope form.

SteerInput

Additional user input steering the current turn.

Fields

user_input: UserInput

The steering input.

BtwBegin

A side question (/btw) has started processing.

Added in Wire protocol v1.9.

Fields

id: String

Unique ID to pair with the corresponding BtwEnd.

question: String

The user’s original side question text.

BtwEnd

A side question (/btw) has finished processing.

Added in Wire protocol v1.9.

Fields

id: String

Unique ID matching the corresponding BtwBegin.

response: Option<String>

The LLM’s response text, or null if it failed.

error: Option<String>

Error message if the side question failed.

PlanDisplay

Plan display content.

Fields

content: String

Display content.

file_path: String

File path associated with the plan.

HookTriggered

A hook was triggered.

Fields

event: String

Event name.

target: String

Target of the hook.

hook_count: u32

Number of times this hook has fired.

HookResolved

A hook was resolved.

Fields

event: String

Event name.

target: String

Target of the hook.

action: HookAction

Action taken.

reason: String

Reason for the action.

duration_ms: u64

Duration in milliseconds.

Implementations

impl Event

pub const fn type_name(&self) -> &'static str

Return the wire type name for this event.

Matches the type field in the wire envelope.

Trait Implementations

impl Clone for Event

fn clone(&self) -> Event

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Event

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Event

fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error>

Deserialize this value from the given Serde deserializer.

impl EventExt for Event

fn event_type(&self) -> String

Return the Pascal-case wire type name (e.g. "TurnBegin").

fn normalized_event_type(&self) -> String

Return the snake-case normalized type name (e.g. "turn_begin").

fn payload(&self) -> Value

Serialize the event back to a JSON value.

impl PartialEq for Event

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

fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error>

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Event