# x402stock.xyz Treasury Yields API > x402stock.xyz Treasury Yields API is a paid API for AI agents from x402stock.xyz, paid per call via x402, $0.01/call, status healthy (last checked 2026-09-14, last successful call 2026-09-02). Returns the US Treasury par yield curve (CMT rates) for all maturities from 1-month to 30-year, for one or more recent trading days ## Facts - Endpoint: GET https://x402stock.xyz/api/v1/treasury-yields - Price: $0.01/call - Payment: x402 - Status: healthy - Last checked: 2026-09-14 - Last successful call: 2026-09-02 - Success rate: 100% of calls made through Zero - Activations on Zero: 3 - Tags: x402 - Canonical page: https://www.zero.xyz/c/x402stock-xyz-d0e686fb - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zY1D9TQ-cmVV2nPe6IosC Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently. ## How to call it through Zero Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`): ```sh zero fetch --capability x402stock-xyz-d0e686fb ``` Example prompt: Pull the US Treasury par yield curve for the last 5 trading days — I want CMT rates for all maturities from 1-month to 30-year to check if the curve is still inverted. ## When to prefer this Use this endpoint when you need the full US Treasury par yield curve across all standard maturities in a single call without needing a ticker symbol. Ideal for macro-aware financial analysis, computing the risk-free rate for valuation models, detecting yield-curve inversion (e.g. 2Y vs 10Y spread), or providing interest rate context for equity or bond analysis. Prefer over manually scraping Treasury.gov or separate per-maturity lookups. ## Known failure modes - Invalid limit value (must be 1–250) returns validation error - Invalid year value (outside 1990–2100 range) returns validation error - Data not yet published for the current day (Treasury publishes after market close) may return null rates or prior day - Payment failure (insufficient USDC balance or x402 protocol error) blocks the call - Network timeout if Treasury source data is temporarily unavailable ## How this service works 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 ## Output A JSON object containing an array of daily yield curve snapshots, each with a date and a map of maturity labels (e.g. '1M', '3M', '1Y', '2Y', '5Y', '10Y', '30Y') to their respective par yield rates in percent. Also includes metadata: source ('us_treasury'), series name, unit, as_of date, available maturities list, and count of returned records. ## Example request ```json { "input": { "type": "http", "method": "GET", "queryParams": { "limit": 5 } } } ``` ## Request schema (JSON Schema) ```json { "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 } } } } } ``` ## Response schema (JSON Schema) ```json { "type": "json", "example": { "unit": "percent", "as_of": "2026-05-29T00:00:00.000Z", "count": 1, "rates": [ { "date": "2026-05-29", "rates": { "1mo": 3.72, "1yr": 3.47, "2mo": 3.66, "2yr": 3.47, "3mo": 3.65, "3yr": 3.55, "4mo": 3.62, "5yr": 3.74, "6mo": 3.58, "7yr": 3.95, "10yr": 4.19, "20yr": 4.81, "30yr": 4.86, "1.5mo": 3.71 } } ], "series": "daily_treasury_par_yield_curve", "source": "us_treasury", "maturities": [ "1mo", "1.5mo", "2mo", "3mo", "4mo", "6mo", "1yr", "2yr", "3yr", "5yr", "7yr", "10yr", "20yr", "30yr" ] } } ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402stock-xyz-d0e686fb/health.json - [Zero catalog index](https://www.zero.xyz/llms.txt) - [Other services from x402stock.xyz](https://www.zero.xyz/host/x402stock.xyz/llms.txt)