Open the agent and click Manage:
Logs: a day-by-day activity feed of the agent's actions, scheduled runs and messages, including the credits its replies used. You can download a whole day's file; save the ones you want to keep, because older logs are removed over time (see log retention).
Transactions: the agent's credit ledger, with each reply's charge (model and tokens) plus renewals, credit packs and upgrades.
A plan paid from your Wiro balance also shows as a PAYMENT row in your wallet's Transactions, and under General in Project Usage (see How do I see how much I've spent?).
Running low? See getting more credits. API: Logs and TransactionList.