Events

Turn / TurnOpts call onEvent for each agent_event frame. Same JSON the CLI prints in abox exec.

sess.Turn(ctx, prompt, func(ev abox.Event) {
    switch ev.Kind {
    case "text":
        fmt.Print(ev.Text)
    case "tool":
        fmt.Printf("[%s %s]\n", ev.Tool, ev.Status)
    case "result":
        if ev.Usage != nil {
            fmt.Printf("tokens in=%d out=%d\n", ev.Usage.InputTokens, ev.Usage.OutputTokens)
        }
    case "error":
        fmt.Fprintln(os.Stderr, ev.Err)
    case "done":
        fmt.Println()
    }
})

Kinds

Kind	Fields	Notes
text	Text	Incremental model output
tool	Tool, Status, Text, Err	ok or error. Rich: ToolID, ToolArgs
result	Usage, StopReason	Protocol 2, rich events
error	Err	Provider or agent failure
done		Turn finished (CLI also uses this)

TurnResult is filled from the result event when present, plus Canceled if the guest returned code: canceled.

See print-events.