OpenAI Usage API api_key_id grouping solves a practical reporting gap: I can see which API key produced completion-token activity and which key accumulated cost. The tricky part is not making the two requests. It is joining their daily buckets without dropping unattributed or unmatched data. I want a reconciliation report to expose gaps, not smooth them over. A missing cost row, a cost-only row, or a null key ID can each be useful evidence. This pattern keeps those cases visible with a dete...