US federal debt cost-of-borrowing intelligence (monthly)

Monthly intelligence on the effective interest rate the U.S. federal government pays on its outstanding debt, from the Treasury FiscalData average-interest-rates table joined to the daily debt-to-penny outstanding balance (both keyless). Each row is one month x one security class (~17 classes, 2001-01 -> ): effective average rate, month-over-month and year-over-year changes in basis points, spread vs the overall debt rate, month-end total public debt outstanding, the bills-vs-notes funding spread, and — on total-debt rows — the estimated annualized interest burden, its YoY change, a documented 0-100 debt-cost-pressure score, and record/rapid-rise/bills-premium flags. Units: percent, basis points, USD, scores. Caveats: effective rates on the outstanding stock (not marginal new-issue rates); the burden is an estimate, not Treasury's published net-interest outlay; honest nulls where a series did not exist; amounts nominal; recent months occasionally revised. Primary key: (month, security_class). Cadence: monthly; as_of is the latest month in the panel, so identical input produces an identical content hash. U.S. federal government work (public domain) — commercial_use = yes, attribution required. Sample use: track debt_cost_pressure_score and annualized_interest_burden_usd for the fiscal cost of rising rates.