> ## Documentation Index
> Fetch the complete documentation index at: https://docs.keywordsai.co/llms.txt
> Use this file to discover all available pages before exploring further.

# Log thinking blocks

> How to log LLM requests that include thinking blocks

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

## 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

## Example Request

```json theme={"system"}
{
  "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?"
    }
  ]
}
```

## Example Response

```json theme={"system"}
{
  "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": []
    }
  ]
}
```

## 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

## 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](../gateway/advanced_features/thinking) documentation.