Glossary
Ephemeral 5-minute vs 1-hour cache explained
Claude's two cache-write durations, billed at different rates — the split most trackers ignore.
Why it matters for cost
5-minute write = 1.25x input; 1-hour write = 2x input. Pricing all writes at 1.25x under-bills ~60%.
How JP the Cat surfaces it
JP the Cat reads the real token counts behind this from the local logs on your Mac and prices them at the shipped rates — so it shows up in your actual cost, not an estimate.
Common questions
- What is ephemeral 5-minute vs 1-hour cache?
- Claude's two cache-write durations, billed at different rates — the split most trackers ignore.
- How does it change what I pay?
- 5-minute write = 1.25x input; 1-hour write = 2x input. Pricing all writes at 1.25x under-bills ~60%.