US National Debt — daily "Debt to the Penny" via US Treasury Fiscal Data. Each row carries record_date, debt held by public, intragovernmental holdings, and total public debt outstanding (all USD, signed integers as strings to preserve precision). Optional `filter` uses Fiscal Data syntax: `col:op:val` joined by commas (ops: eq, lt, lte, gt, gte, in). Default sort is `-record_date` (newest first). Authoritative source for "how much does the US owe?" — every weekday since 1993.