{"uid":"cap_pF-5l0JoUmI24We61SNVP","slug":"us-treasury-par-yield-curve-cmt-rates-2cf3af3f","name":"US Treasury Par Yield Curve (CMT Rates)","description":"The daily US Treasury par yield curve (Constant Maturity Treasury rates) for every maturity from 1 month to 30 years, in percent. Defaults to the latest published day; pass `?limit=` for more recent days (max 250) and `?year=YYYY`. No ticker needed. Use for the risk-free rate, rate-sensitivity context, and yield-curve inversion in macro-aware analysis. From x402stock","url":"https://x402stock.vercel.app/api/v1/treasury-yields","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"queryParams":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["limit"],"properties":{"year":{"type":"integer","maximum":2100,"minimum":1990},"limit":{"type":"integer","default":1,"maximum":250,"exclusiveMinimum":0}},"additionalProperties":false}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["source","as_of","series","unit","maturities","count","rates"],"properties":{"unit":{"type":"string"},"as_of":{"anyOf":[{"type":"string"},{"type":"null"}]},"count":{"type":"number"},"rates":{"type":"array","items":{"type":"object","required":["date","rates"],"properties":{"date":{"type":"string"},"rates":{"type":"object","propertyNames":{"type":"string"},"additionalProperties":{"anyOf":[{"type":"number"},{"type":"null"}]}}},"additionalProperties":false}},"series":{"type":"string"},"source":{"type":"string","const":"us_treasury"},"maturities":{"type":"array","items":{"type":"string"}}},"additionalProperties":false}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_DZHWqTLkeTyuaF1EWUem7","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns the daily US Treasury par yield curve (Constant Maturity Treasury rates) for all maturities from 1 month to 30 years, in percent.","exampleAgentPrompt":"Pull the latest US Treasury par yield curve — all maturities from 1 month to 30 years — so I can check if the curve is inverted and grab the risk-free rate for my valuation model.","exampleUseCases":null,"resultDescription":"Returns an array of dated records, each containing CMT yield rates (in percent) keyed by maturity label (e.g. '1M', '3M', '2Y', '10Y', '30Y'), along with metadata including source ('us_treasury'), as_of date, list of maturities, unit ('percent'), and count of records returned.","failureModes":["Invalid year parameter outside 1990-2100 range returns validation error","Limit exceeding 250 returns error; limit must be a positive integer","No data available for requested year (e.g. future year) returns empty or null","Rate limiting or payment failure returns 402 payment required","Treasury data may lag by one business day; weekends/holidays return last published day"],"whenToPreferThis":"Use this endpoint when you need authoritative US Treasury CMT rates for risk-free rate inputs, yield curve shape analysis (inversion detection), interest rate sensitivity context, or macro-aware financial modeling — without needing any stock ticker or security identifier. Prefer over scraping Treasury.gov or using stale cached data.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T06:43:59.105Z","isFirstParty":false}