Enum EngineStreamEvent 

pub enum EngineStreamEvent {
    Thinking(String),
    Text(String),
    ToolStart {
        tool_id: String,
        tool_name: String,
    },
    ToolDelta {
        tool_id: String,
        delta: String,
    },
    ToolFinalized {
        tool_id: String,
        tool_name: String,
        input: Value,
    },
    ToolResultDelta {
        tool_id: String,
        delta: String,
    },
    ToolResult {
        tool_id: String,
        result: String,
    },
    SubagentStart {
        id: u64,
        name: String,
        task: String,
    },
    SubagentUpdate {
        id: u64,
        status: String,
    },
    SubagentDone {
        id: u64,
        status: String,
        duration_secs: f64,
    },
    SteeringDelivered {
        message: String,
    },
    Usage {
        input_tokens: u64,
        output_tokens: u64,
        cache_read: u64,
        cache_creation: u64,
        model: Option<String>,
    },
    Noop,
    Notice(String),
    Done,
    Error(String),
}

What happened during a stream event — renderer decides how to display.

Variants

Thinking(String)

Thinking text arrived.

Text(String)

Response text arrived.

ToolStart

Tool use started.

Fields

tool_id: String

tool_name: String

ToolDelta

Tool use input delta.

Fields

tool_id: String

delta: String

ToolFinalized

Tool use finalized.

input is the parsed JSON value, not a stringified version. Renderers that need a string preview (chat.rs, server’s HistoryEntry::ToolUse) can call serde_json::to_string themselves; the wire-format ToolUse in server mode passes the Value through directly.

Fields

tool_id: String

tool_name: String

input: Value

ToolResultDelta

Tool result delta.

Fields

tool_id: String

delta: String

ToolResult

Tool result complete.

Fields

tool_id: String

result: String

SubagentStart

Subagent dispatched.

Fields

id: u64

name: String

task: String

SubagentUpdate

Subagent status update.

Fields

id: u64

status: String

SubagentDone

Subagent finished.

Fields

id: u64

status: String

duration_secs: f64

SteeringDelivered

Steering message was delivered.

Fields

message: String

Usage

Usage stats for this turn.

Fields

input_tokens: u64

output_tokens: u64

cache_read: u64

cache_creation: u64

model: Option<String>

Noop

Internal bookkeeping — no visual output.

Notice(String)

Display-only status notice (e.g. API retry). Not part of the transcript.

Done

Stream completed.

Error(String)

Stream errored.

Trait Implementations

impl Debug for EngineStreamEvent

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

Formats the value using the given formatter.