Rebuilt billing mid-June around one rule: I should be able to explain any invoice in one breath and reproduce it by hand from the usage records.
Monthly billing lives in a single system of record now instead of being assembled from pieces at invoice time. The free tier's $5/mo is applied as an actual invoice discount -- you see the usage, you see the credit, you see the difference -- not invisible pre-invoice math. Credits moved to a plain counter: how many grants you hold, how many cents they're worth, incremented and decremented like a ledger. Ledger arithmetic is the kind you can check by hand. And when a charge fails transiently on the payment processor's side, we retry instead of producing a mystery gap you'd have to email us about.
The free tier itself didn't change: $5 in credits monthly, no strings, card requested around day 90. The card gates the CREDIT, not your data. No card, the monthly credit stops -- your collections and your export button keep working exactly as before.
Boring on purpose. Excitement in billing is always bad news.