Method dispatchHook

pkg/runtime/hooks.go:93–129

dispatchHook is the common dispatch path shared by every hook callsite: resolve the pre-built executor, dispatch, and emit any [Result.SystemMessage] as a Warning event. Errors are logged at warn level and surfaced as nil results so callers can use a single nil check to mean "nothing useful came bac

(
	ctx context.Context,
	a *agent.Agent,
	event hooks.EventType,
	input *hooks.Input,
	events EventSink,
)

// silently logged, since those events are themselves the user-facing
// notification mechanism.
func (r *LocalRuntime) dispatchHook(
	ctx context.Context,
	a *agent.Agent,
	event hooks.EventType,
	input *hooks.Input,
	events EventSink,
) *hooks.Result {
	exec := r.hooksExec(a)
	if exec == nil || !exec.Has(event) {
		return nil
	}

	// Auto-fill AgentName for events whose Input builder omits it (tool
	// events via toolexec.NewHooksInput), mirroring Cwd auto-fill in
	// Executor.Dispatch. Caller-set values win.
	if input != nil && input.AgentName == "" {
		input.AgentName = a.Name()
	}

	started := time.Now()
	if events != nil {
		events.Emit(HookStarted(event, input.SessionID, a.Name()))
	}
	result, err := exec.Dispatch(ctx, event, input)
	if events != nil {
		events.Emit(HookFinished(event, input.SessionID, result, err, time.Since(started), a.Name()))
	}
	if err != nil {
		slog.WarnContext(ctx, "Hook execution failed", "event", event, "agent", a.Name(), "error", err)
		return nil
	}

	if events != nil && result.SystemMessage != "" {
		events.Emit(Warning(result.SystemMessage, a.Name()))
	}
	return result
}

// executeSessionStartHooks fires session_start once at the top of
// RunStream and returns its AdditionalContext as transient system