{"uid":"cap_s0DOHmw3enONUXkfR68Pk","slug":"us-treasury-par-yield-curve-api-6d368f67","name":"US Treasury Par Yield Curve API","description":"US Treasury par yield curve, every constant maturity from 1 month to 30 years for a published business day. Returns curve[] with tenor, months and percent, spreads (2s10s, 3m10y, 5s30s) and an explicit inversion flag - the real question is whether the curve is inverted, not what fourteen numbers are. A tenor Treasury did not publish is null, never zero. Pass ?latest=1 OR ?date=YYYY-MM-DD, not both. Errors: 400 conflicting_params|bad_latest|bad_date, 404 no_curve with the available range.","url":"https://x402.donnyautomation.com/treasury?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":[],"properties":{"date":{"type":"string","description":"YYYY-MM-DD business day, for a specific past day. A non-publication day returns 404 with the available range, not the nearest guess."},"latest":{"type":"string","description":"Pass latest=1 for the most recent published curve. Use instead of date, not with it."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"ts":"2026-08-03T00:00:00.000Z","date":"2026-08-03","curve":[{"tenor":"3 Mo","months":3,"percent":3.91},{"tenor":"2 Yr","months":24,"percent":4.25},{"tenor":"10 Yr","months":120,"percent":4.7}],"spreads":{"unit":"percentage points","2s10s":0.45,"3m10y":0.79,"5s30s":0.83},"isLatest":true,"inversion":{"2s10s":false,"3m10y":false,"anyInverted":false},"attribution":"Daily Treasury Par Yield Curve Rates, U.S. Department of the Treasury (public domain)."}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.03","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.03/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.03","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.03","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_npew1w3HVjkjgVvojCSlA","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.03","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns the full US Treasury constant-maturity par yield curve for any published business day, including key spreads (2s10s, 3m10y, 5s30s) with explicit yield curve inversion flags.","exampleAgentPrompt":"Pull the latest US Treasury par yield curve and tell me whether it's inverted — I specifically want the 2s10s, 3m10y, and 5s30s spreads and the explicit inversion flags.","exampleUseCases":[{"title":"Real-time yield curve inversion check","prompt":"Is the Treasury yield curve currently inverted? Give me the 2s10s and 3m10y spreads and tell me clearly whether each one is in inversion territory right now."},{"title":"Historical spread lookup for macro report","prompt":"What were the 2s10s, 3m10y, and 5s30s Treasury spreads on March 15, 2023? I need to know if the curve was inverted that day for a macro analysis I'm writing."},{"title":"Full CMT rates for risk model input","prompt":"Fetch the complete US Treasury constant-maturity yield curve for the most recent published business day — I need all tenors from 1 month to 30 years, with nulls for any that weren't published that day, for my risk model."}],"resultDescription":"A structured JSON object containing all published US Treasury constant-maturity par yield rates from 1-month to 30-year for the requested business day, key spreads (2s10s, 3m10y, 5s30s) pre-computed, an explicit boolean inversion flag per spread, and null (not zero) for any tenor the Treasury did not publish that day. Returns 404 with available date range if a non-publication day is requested.","failureModes":["404 if requested date is not a Treasury publication day (weekend, holiday, or no data), with available date range returned","400 if both 'date' and 'latest=1' are supplied simultaneously","400 if date format is invalid or unparseable","Payment failure (402) if USDC payment is not included or insufficient"],"whenToPreferThis":"Choose this endpoint when you need official US Treasury CMT rates for macro, rates, credit, or risk workflows and want key curve spreads and inversion flags pre-computed rather than deriving them yourself. Prefer it over scraping Treasury.gov directly when you need structured JSON output, reliable null-vs-zero semantics for missing tenors, or programmatic inversion detection without extra computation.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-01T12:51:06.408Z","isFirstParty":false,"canonicalSlug":"us-treasury-par-yield-curve-api-6d368f67"}