MEAI: OpenAI - Expose 'cache_write_tokens'

[rwjdk]

In OpenAI 5.6 models or later, OpenAI have introduced cache_write_tokens that indicate how many tokens was billed at 1.25x

In a raw call to OpenAI API it looks like this:

Chat Completion Response:

usage": {
    "prompt_tokens": 9657,
    "completion_tokens": 78,
    "total_tokens": 9735,
    "prompt_tokens_details": {
      "cached_tokens": 0,
      "cache_write_tokens": 9654, <--- New Property in 5.6 models
      "audio_tokens": 0
    },
    "completion_tokens_details": {
      "reasoning_tokens": 37,
      "audio_tokens": 0,
      "accepted_prediction_tokens": 0,
      "rejected_prediction_tokens": 0
    }
  }

Responses API Response

"usage": {
    "input_tokens": 9658,
    "input_tokens_details": {
      "cache_write_tokens": 9655, <--- New Property in 5.6 models
      "cached_tokens": 0
    },
    "output_tokens": 42,
    "output_tokens_details": {
      "reasoning_tokens": 25
    },
    "total_tokens": 9700
  },

It could be nice if MEAI for OpenAI could expose this new property

Note: Only OpenAI's own API Endpoint have exposed this yet... Azure OpenAI are yet to expose the property.