Usage metrics per user

Hello,

I have multiple users that interact with the Amazon Translate API. I wonder if there's a way to know how many characters or how much money each user has requested or spent.

I have tried CloudWatch, but I can only see TranslateText (global) usage and EstimatedCharges (per account, not per user). I'm looking for information about batch jobs too. And not estimated but real costs.

My plan is to save this information on my code but I'd like to make sure there's no way to obtain it using some AWS service.

Thank you so much

David