Enum AgentEvent 

pub enum AgentEvent {
    AgentStart,
    AgentEnd {
        messages: Vec<AgentMessage>,
    },
    RetryScheduled {
        attempt: u32,
        max_retries: u32,
        delay_ms: u64,
        error: String,
    },
    TurnStart,
    TurnEnd {
        message: AgentMessage,
        tool_results: Vec<ToolResultMessage>,
    },
    MessageStart {
        message: AgentMessage,
    },
    MessageUpdate {
        message: Arc<AssistantMessage>,
        assistant_message_event: AssistantMessageEvent,
    },
    MessageEnd {
        message: AgentMessage,
    },
    ToolExecutionStart {
        tool_call_id: String,
        tool_name: String,
        args: Value,
    },
    ToolExecutionUpdate {
        tool_call_id: String,
        tool_name: String,
        args: Value,
        partial_result: Arc<AgentToolResult>,
    },
    ToolExecutionEnd {
        tool_call_id: String,
        tool_name: String,
        result: AgentToolResult,
        is_error: bool,
    },
}

An event emitted by the agent loop. Mirrors TS AgentEvent (tagged on type). AgentMessage payloads are owned (cloned) so broadcast subscribers get independent copies — except AgentEvent::MessageUpdate, which carries the streaming partial as a cheap Arc because it fires once per delta.

Variants

AgentStart

Emitted once at the start of a run, before turn_start.

AgentEnd

Emitted once at the end of a run; carries the new messages produced.

Fields

messages: Vec<AgentMessage>

RetryScheduled

Emitted after a retryable provider failure, before the backoff wait.

Fields

attempt: u32

One-based retry number (the initial request is not counted).

max_retries: u32

Maximum number of retries allowed for this request.

delay_ms: u64

Backoff duration before the next provider request.

error: String

Diagnostic from the failed provider request.

TurnStart

Emitted at the start of each turn (a turn = one assistant response + its tool calls/results).

TurnEnd

Emitted after a turn’s assistant message + tool results settle. Carries the assistant message (as an AgentMessage) and the tool-result messages produced this turn, in source/ordinal order.

Fields

message: AgentMessage

tool_results: Vec<ToolResultMessage>

MessageStart

Emitted when any message (user prompt, assistant response, tool result, custom) is appended to the transcript.

Fields

message: AgentMessage

MessageUpdate

Emitted only for assistant messages, on each streaming delta. Carries the underlying AssistantMessageEvent plus a shared snapshot of the partial assistant message.

The snapshot is an Arc, not an owned message: a delta used to deep-clone the whole growing message here, again in the loop’s context update, and again in each consumer — quadratic in the output length. Consumers that need it as JSON use crate::message::assistant_json to keep the wire shape identical without copying.

Fields

message: Arc<AssistantMessage>

assistant_message_event: AssistantMessageEvent

MessageEnd

Emitted when a message finishes (complement of MessageStart).

Fields

message: AgentMessage

ToolExecutionStart

Emitted before a tool call starts executing.

Fields

tool_call_id: String

tool_name: String

args: Value

ToolExecutionUpdate

Emitted on a partial tool result pushed via on_update.

Fields

tool_call_id: String

tool_name: String

args: Value

partial_result: Arc<AgentToolResult>

ToolExecutionEnd

Emitted when a tool call finishes (success or error). is_error marks the error path; result carries the final tool result.

Fields

tool_call_id: String

tool_name: String

result: AgentToolResult

is_error: bool

Implementations

impl AgentEvent

pub fn type_tag(&self) -> &'static str

pub fn is_terminal(&self) -> bool

True for the terminal AgentEnd event.

Trait Implementations

impl Clone for AgentEvent

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for AgentEvent

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

Formats the value using the given formatter.