Settings → Usage answers “where did the credits go?” with data rather than guesswork. It’s admin-visible, and it covers the whole organization.

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The rollup

Spend is shown per day across the date range you pick, broken down by kind:
  • Model: the thinking, in chat replies and runs
  • Tools: actions taken in connected apps
Pick a wider range for the trend, a narrow one to investigate a spike.

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Reading it well

Usage tells you when and what kind; Agent history tells you which job, with a credit cost on every run. The two together settle any question in a couple of minutes: find the heavy day in Usage, then find the heavy runs in that day’s history.