Enum AgentEvent 

#[non_exhaustive]
pub enum AgentEvent {
    TurnStart {
        turn: u32,
    },
    LlmStreamEvent {
        event: StreamEventRef,
    },
    ToolExecuting {
        tool_use_id: String,
        name: String,
        input: ToolInput,
    },
    ToolComplete {
        tool_use_id: String,
        name: String,
        result: Option<ToolResult>,
        error: Option<String>,
    },
    ContextCompacted {
        old_tokens: usize,
        new_tokens: usize,
    },
    TurnComplete {
        turn: u32,
        message: AssistantMessage,
        usage: Usage,
    },
    Complete {
        result: AgentResult,
    },
}

Events emitted during an agent run (for streaming / observability).

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.

TurnStart

A new turn is starting.

Fields

turn: u32

Turn number being started.

LlmStreamEvent

An LLM streaming event was received.

Fields

event: StreamEventRef

Streaming event received from the LLM provider.

ToolExecuting

A tool is about to be executed.

Fields

tool_use_id: String

Provider tool-use identifier.

name: String

Tool name.

input: ToolInput

Tool input payload.

ToolComplete

A tool call completed.

Fields

tool_use_id: String

Provider tool-use identifier.

name: String

Tool name.

result: Option<ToolResult>

Successful tool result, when available.

error: Option<String>

Error text, when execution failed.

ContextCompacted

Context was compacted to fit within the token budget.

Fields

old_tokens: usize

Previous approximate token count.

new_tokens: usize

New approximate token count.

TurnComplete

A turn completed.

Fields

turn: u32

Completed turn number.

message: AssistantMessage

Assistant message produced by the turn.

usage: Usage

Token usage for the turn.

Complete

The agent run is complete.

Fields

result: AgentResult

Final agent result.