Method executeTurnStartHooks

pkg/runtime/hooks.go:159–163

executeTurnStartHooks fires turn_start before each model call and returns its AdditionalContext as transient system messages. Like session_start the result is never persisted, but turn_start runs every iteration so its content is recomputed each turn — the right semantics for fast-changing context l

(ctx context.Context, sess *session.Session, a *agent.Agent, events EventSink)

// semantics for fast-changing context like the current date or the
// contents of a prompt file the user might be editing mid-session.
func (r *LocalRuntime) executeTurnStartHooks(ctx context.Context, sess *session.Session, a *agent.Agent, events EventSink) []chat.Message {
	return contextMessages(r.dispatchHook(ctx, a, hooks.EventTurnStart, &hooks.Input{
		SessionID: sess.ID,
	}, events))
}

// Reason values reported in [hooks.Input.Reason] when [hooks.EventTurnEnd]
// fires. The runtime guarantees that turn_end runs once per turn that