# US Treasury Average Interest Rates

> US Treasury Average Interest Rates is a paid API for AI agents from x402-datashop-production.up.railway.app, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Returns monthly average interest rates the US Treasury pays on outstanding securities, sourced from the official FiscalData API, filterable by security type and date range.

## Facts

- Endpoint: GET https://x402-datashop-production.up.railway.app/v1/us/treasury-rates
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/us-treasury-average-interest-rates-e6e87ed2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_KFT5HXUyIyH-sW63n5Iz0

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-average-interest-rates-e6e87ed2
```

Example prompt: Can you pull the last 12 months of average interest rates the US Treasury is paying on Treasury Bills, going back to January 2024?

## When to prefer this

Use this endpoint when you need official, government-sourced monthly average interest rates the US Treasury pays on its outstanding securities (Bills, Notes, Bonds, etc.). Prefer this over third-party rate aggregators when regulatory accuracy and official sourcing matter, or when you need historical monthly series going back several years.

## Known failure modes

- Invalid or misspelled security_desc returns no results or an error
- since date in wrong format (not ISO date) causes a 400 bad request
- limit outside 1-100 range is rejected
- Upstream FiscalData API unavailable causes a 502 or cached stale response
- Requesting data before the dataset's earliest record returns empty results

## How this service works

Monthly average interest rates the US Treasury pays on its outstanding securities, from the official FiscalData API (Average Interest Rates dataset, updated monthly). Query: ?security=Treasury Bills (exact security_desc, optional; e.g. Treasury Notes, Treasury Bonds) &since=2026-01-01 (optional record_date floor) &limit=12 (1-100, newest first). Returns record_date, security type/name and avg rate in percent. Cached 24h.

## Output

A list of monthly records (newest first, up to the requested limit) each containing record_date, the security description (e.g. Treasury Bills, Treasury Notes), and the average interest rate in percent. Results are cached for 24 hours and sourced from the official US Treasury FiscalData API.

## 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",
     "properties": {
      "limit": {
       "type": "integer",
       "default": 12,
       "description": "Max records, newest first (1-100)"
      },
      "since": {
       "type": "string",
       "description": "Only records with record_date >= this ISO date"
      },
      "security": {
       "type": "string",
       "description": "Exact security_desc filter, e.g. Treasury Bills"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/us-treasury-average-interest-rates-e6e87ed2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-datashop-production.up.railway.app](https://www.zero.xyz/host/x402-datashop-production.up.railway.app/llms.txt)