{"endpoints":{"/toll/rates/curve":"full yield curve for a date (toll $0.02). param: date=YYYY-MM-DD (default: latest)","/toll/rates/history":"time series per tenor (toll $0.02). params: tenor, start, end, limit","/toll/rates/spreads":"key curve spreads (toll $0.02). param: date (default: latest)","/toll/rates/schema":"this schema (free)"},"tenors":"14 tenors: 1mo, 1.5mo, 2mo, 3mo, 4mo, 6mo, 1yr, 2yr, 3yr, 5yr, 7yr, 10yr, 20yr, 30yr","sources":"U.S. Department of the Treasury Daily Par Yield Curve Rates (official XML feed). No FRED.","vintage":"Data vintage: a fixed historical snapshot of the Daily Treasury Par Yield Curve Rates — business days 1990-01-02 through 2026-10-09, collected October 2026 from the official U.S. Department of the Treasury feed (fiscaldata.treasury.gov / home.treasury.gov), whose terms offer the data free, without restriction, for commercial redistribution. Dates after 2026-10-09 are not covered by this snapshot.","licence":"Licence: the underlying data is offered free, without restriction, and available to copy, adapt, redistribute, or otherwise use for non-commercial or commercial purposes (U.S. Department of the Treasury, fiscaldata.treasury.gov API documentation)."}