{
  "model": "claude-opus-5",
  "messages": [
    {"role": "system", "content": [
      {"type": "text", "text": "You are a helpful assistant."},
      {"type": "text", "text": "Always be concise."}
    ]},
    {"role": "user", "content": "Hi"}
  ],
  "max_tokens": 100
}