API endpoints for Billing info by API key

I am creating and using multiple API keys for multiple projects.

Is there any OpenAI API endpoints which can gimme breakup of Usage by API keys, on daily/monthly basis?

Hi and welcome to the forum!

Think of OpenAI as an electricity supplier, they track your usage but not what it is used for. It is your responsibility to track, via libraries like GitHub - openai/tiktoken: tiktoken is a fast BPE tokeniser for use with OpenAI's models., your approximate usage per API key. API keys can be revoked and created anew, tracking that is extra work and load on the system.