export type UserMessage = { role: 'user'; content: string };
export type AssistantMessage = {
  role: 'assistant';
  content: string;
  tool_calls?: { id: string; name: string; arguments: Record<string, unknown> }[];
};
export type SystemMessage = { role: 'system'; content: string };
export type ToolMessage = { role: 'tool'; id: string; name: string; content: string };

export type Message = UserMessage | AssistantMessage | SystemMessage | ToolMessage;
export type ChatTurnMessage = UserMessage | AssistantMessage;
