When using models with thinking capabilities, the response includes additional reasoning information that can be logged and analyzed.

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Response Structure

Thinking-enabled responses include these additional fields:
  • reasoning_content: The model’s reasoning process in text format
  • thinking_blocks: Array of structured thinking blocks with signatures

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Example Request

{
  "model": "claude-sonnet-4-20250514",
  "max_tokens": 16000,
  "thinking": {
    "type": "enabled",
    "budget_tokens": 10000
  },
  "messages": [
    {
      "role": "user",
      "content": "Are there an infinite number of prime numbers such that n mod 4 == 3?"
    }
  ]
}

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Example Response

{
  "messages": [
    {
      "role": "user",
      "content": "Are there an infinite number of prime numbers such that n mod 4 == 3?"
    },
    {
      "role": "assistant",
      "content": "Yes, there are infinitely many prime numbers such that n ≡ 3 (mod 4).\n\nThis is a classic theorem in number theory, and here's a proof…",
      "reasoning_content": "This is asking about whether there are infinitely many prime numbers that are congruent to 3 modulo 4, i.e., primes of the form 4k + 3.\n\nLet me think about this systematically. First…",
      "thinking_blocks": [
        {
          "type": "thinking",
          "thinking": "This is asking about whether there are infinitely many prime numbers that are congruent to 3 modulo 4, i.e…",
          "signature": "EswgCkYIBhgCKkDCG…"
        }
      ],
      "tool_calls": []
    }
  ]
}

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Logging Parameters

All standard logging parameters apply. The thinking-related fields are automatically captured when present:
  • reasoning_content: Full reasoning text
  • thinking_blocks: Array of thinking block objects
  • signature: Cryptographic signature for thinking block verification

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Key Points

  • Thinking blocks are automatically logged when present in the response
  • The reasoning_content field contains the complete reasoning process
  • thinking_blocks provide structured access to individual reasoning steps
  • All other logging parameters work the same as regular text logging
For more information on enabling thinking mode, see the Enable Thinking documentation.