Method run

internal/llm/llm.go:292–338

(parent context.Context, msgs []chmctx.Message, tools []Tool, out chan<- Event)

	})
	if err != nil {
		return ProbeResult{Budget: budget}, err
	}
	defer resp.Body.Close()
	return ProbeResult{
		ContextWindow: cloud.ContextWindowFromHeaders(resp.Header),
		Budget:        cloud.FromHeaders(resp.Header),
	}, nil
}

// Chat streams an assistant response on the returned channel, closing it when
// the stream ends. Reasoning runs at `high` effort by default; if the server
// rejects the tools + reasoning_effort combo (newer OpenAI models do), postChat
// drops reasoning_effort for this Client's lifetime so the model still works,
// with tools but no reasoning. Staying on chat-completions is the product line;
// we do not branch to /v1/responses to keep reasoning.
func (c *Client) Chat(parent context.Context, messages []chmctx.Message, tools []Tool) <-chan Event {
	out := make(chan Event, 32)
	go c.run(parent, messages, tools, out)
	return out
}

func (c *Client) run(parent context.Context, msgs []chmctx.Message, tools []Tool, out chan<- Event) {
	defer close(out)
	start := time.Now()

	// Pre-stream retry: transient failures (proxy hiccups: 5xx, 429, LiteLLM's
	// transient 404) are resent after a rising backoff instead of killing the
	// turn. Only here, before any token has streamed — a mid-stream resend
	// would duplicate content already in the transcript. Probe stays
	// retry-free: its job is fast feedback on a misconfigured profile.
	resp, errEvt := c.sendChat(parent, msgs, tools)
	for attempt := 0; errEvt != nil && attempt < len(c.RetryBackoff) && retryable(errEvt.Err); attempt++ {
		delay := c.RetryBackoff[attempt]
		hint := fmt.Sprintf("retry %d/%d in %s", attempt+1, len(c.RetryBackoff), delay)
		if !sendEvent(parent, out, Event{Kind: EventRetry, Content: hint, Err: errEvt.Err}) {
			return
		}
		select {
		case <-time.After(delay):
		case <-parent.Done():
			// Ctrl+C during the wait: unwind silently, exactly like a
			// cancelled sendEvent — the TUI already aborted the turn.
			return
		}
		resp, errEvt = c.sendChat(parent, msgs, tools)
	}
	if errEvt != nil {
		sendEvent(parent, out, *errEvt)
		return
	}