A US 3-month Treasury yield API returns the front bill, not the 10-year. On Bonds-API the key is US_3M. Call GET https://bonds-api.com/api/v1/latest?countries=US&maturities=3M with query api_key.
Starter is $19/mo with a 7-day trial. This is not SOFR. MCP: mcp.bonds-api.com.
Request: latest US 3M
curl "https://bonds-api.com/api/v1/latest?countries=US&maturities=3M&api_key=YOUR_API_KEY"Sibling: official US curve (2026-04-14)
{
"success": true,
"data": {
"country": "US",
"date": "2026-04-14",
"curve": [
{"maturity": "3M", "yield": 4.30},
{"maturity": "6M", "yield": 4.22}
]
}
}Copy the latest curl for today’s US_3M. The same fixture lists 30Y at 4.55.
Go live
1. Register — 7-day trial.
2. Copy api_key.
3. GET latest with maturities=3M.
4. Render US_3M. Use /curve for the full bill–bond set.