# US Treasury Yield Curve — Constant-Maturity Yields

> US Treasury Yield Curve — Constant-Maturity Yields is a paid API for AI agents from marketdata.use.x402atlas.com, paid per call via x402, $0.015/call, status unknown (last checked 2026-10-12).

Returns daily US Treasury constant-maturity yields across the full curve from 1-month to 30-year, with historical date range filtering.

## Facts

- Endpoint: GET https://marketdata.use.x402atlas.com/treasury-yields?utm_source=zero.xyz
- Price: $0.015/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/us-treasury-yield-curve-constant-maturity-yields-55489626
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5t0n1_SH6zCuXCUrt6YLU

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 us-treasury-yield-curve-constant-maturity-yields-55489626
```

Example prompt: Pull the US Treasury constant-maturity yield curve for every trading day from January 1 to March 31, 2025 — I need all maturities from 1-month to 30-year.

## When to prefer this

Use this endpoint when you need official US Treasury constant-maturity benchmark yields — the risk-free rate curve used in bond pricing, spread analysis, duration modeling, or macro research. Prefer this over inflation or CPI endpoints when the specific need is nominal interest rates or yield curve shape (normal/inverted/flat). Best for daily granularity with historical depth; not for intraday rate movements.

## Known failure modes

- Date out of range — no Treasury data available before Fed series start date
- Invalid date format — must be YYYY-MM-DD
- No data for requested date — weekend or holiday with no observation
- Limit exceeded or zero results returned for narrow date range
- Payment failure — x402 micropayment of $0.015 USDC not processed

## How this service works

US Treasury yield curve — constant-maturity market yields from 1-month to 30-year, daily history.

## Output

Returns daily observations of US Treasury constant-maturity yields across all standard maturities (1-month, 3-month, 6-month, 1-year, 2-year, 3-year, 5-year, 7-year, 10-year, 20-year, 30-year), with observation dates and rate values in percentage terms. Supports filtering by exact date or date range, and pagination via limit parameter.

## 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"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "limit": {
       "type": "integer",
       "maximum": 50000,
       "minimum": 1,
       "description": "Max observations returned"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "queried_at",
      "series",
      "count",
      "observations"
     ],
     "properties": {
      "count": {
       "type": "integer",
       "description": "Number of observations returned."
      },
      "series": {
       "type": "string",
       "description": "Which macro series this response is for."
      },
      "queried_at": {
       "type": "string",
       "format": "date-time",
       "description": "UTC timestamp when this bridge queried the upstream."
      },
      "observations": {
       "type": "array",
       "items": {
        "type": "object"
       },
       "description": "Raw upstream observations for the series, passed through as reported (shape varies by series)."
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "count": 1,
  "series": "treasury-yields",
  "queried_at": "2026-07-06T12:00:00Z",
  "observations": [
   {
    "date": "2025-06-01",
    "yield_2_year": 3.9,
    "yield_10_year": 4.2,
    "yield_30_year": 4.5
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/us-treasury-yield-curve-constant-maturity-yields-55489626/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from marketdata.use.x402atlas.com](https://www.zero.xyz/host/marketdata.use.x402atlas.com/llms.txt)