AI chat interface

export type Message = { role: "user" | "assistant"; content: string };

/**
 * Send the conversation to your backend. The backend is responsible for calling the AI provider;
 * never put a provider API key in browser code.
 */
export async function sendMessages(endpoint: string, messages: Message[], signal?: AbortSignal): Promise<string> {
  const res = await fetch(endpoint, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ messages }),
    signal,
  });
  if (!res.ok) throw new Error("Backend responded with " + res.status);
  const data = (await res.json()) as { reply?: unknown };
  if (typeof data.reply !== "string") throw new Error("Backend response is missing a string 'reply' field");
  return data.reply;
}