Why OpenAI.Chat.ChatTokenUsage doesn't have a public property for cached_tokens?

[mr-shevchenko]

In debug, I can view cached tokens via a private property OpenAI.Chat.ChatTokenUsage.SerializedAdditionalRawData, but I want to store this information in my application's logs to monitor this statistic. This is crucial for controlling expenses. If I find out that caching doesn't work in my case for some reason, I will summarize the conversation more often.

[joseharriaga]

Thank you for reaching out, @mr-shevchenko ! We are working to release an update in a few days that will expose this property publicly.

To get you unblocked in the meantime, it should be possible to parse that property manually via the raw response. I believe something like this should work:

ClientResult<ChatCompletion> result = client.CompleteChat(content);
BinaryData output = result.GetRawResponse().Content;

using JsonDocument outputAsJson = JsonDocument.Parse(output.ToString());
string cachedTokenCount = outputAsJson.RootElement
    .GetProperty("usage"u8)
    .GetProperty("prompt_token_details"u8)
    .GetProperty("cached_tokens"u8)
    .GetInt32();

[mr-shevchenko]

Thank you! Your solution works. I'm looking forward to the new build.

If someone needs the same: prompt_tokens_details (additional s).