System Prompts

final agent = Agent('openai');

// Use default assistant
final result1 = await agent.send(
  'Hello!',
  history: [ChatMessage.system('You are a helpful assistant.')],
);
// Response: "Hello! How can I help you today?"

// Use pirate personality
final result2 = await agent.send(
  'Hello!',
  history: [ChatMessage.system('You are a pirate. Speak like one.')],
);
// Response: "Ahoy, matey!"