US 10Y Treasury Yield API: Latest Bond Rates from JSON

A US 10Y Treasury yield API is a REST endpoint that returns the 10-year government bond yield as JSON. On Bonds-API the field is US_10Y (percent). Call GET /api/v1/latest with ISO country codes and optional maturities. Auth is the api_key query parameter — there is no Bearer header.

The official Latest sample is dated 2026-04-14 with US_10Y at 4.25 and DE_10Y at 3.00. That is a docs fixture, not a live tick — copy the curl with your key for today’s print. Docs: bonds-api.com/docs. Starter is $19/mo (1,000 requests, 60/min, 7-day trial). There is also an MCP server at POST https://mcp.bonds-api.com.

Request: latest US, German, and Spanish yields

curl "https://bonds-api.com/api/v1/latest?countries=US,DE,ES&maturities=2Y,10Y&api_key=YOUR_KEY" \
-H "Accept: application/json"

countries is required (comma-separated ISO codes). maturities is optional; omit it to get every tenor the API stores for those countries. Keys look like {CC}_{TENOR} — US_10Y, DE_2Y, ES_10Y.

Response: rates plus meta

Envelope from the official Latest docs (sample date 2026-04-14):

{
"success": true,
"date": "2026-04-14",
"rates": {
"US_2Y": 3.80,
"US_10Y": 4.25,
"DE_2Y": 2.66,
"DE_10Y": 3.00,
"ES_2Y": 2.85,
"ES_10Y": 3.50
},
"meta": {
"request_id": "3efeeaa7-d4ab-4cde-8104-78fd402052a9",
"timestamp": "2026-04-14T09:00:00Z"
}
}

Read rates.US_10Y for the 10-year Treasury. date is the observation date of the snapshot.

Curve and spread (not just latest)

Latest is one tenor snapshot. The landing page also documents a full curve and a cross-country spread on the same api_key:

curl "https://bonds-api.com/api/v1/curve?country=US&api_key=YOUR_KEY"
curl "https://bonds-api.com/api/v1/spread?country=IT&benchmark=DE&maturity=10Y&api_key=YOUR_KEY"

/curve returns every tenor for one ISO country plus spread_2y_10y and inverted (docs-style sample: 10Y 4.25, 2s10s 45 bp, not inverted). /spread is Italy vs Bund 10Y in the official example — swap country=US and benchmark=DE for a Treasury–Bund gap. Historical / timeseries / intraday live on /api/v1 as well if you need a window instead of a print.

Go live with US_10Y

1. Register and start the 7-day trial (Starter is $19/mo after).

2. Confirm country codes on /docs (US, DE, ES, JP, and 60+ more).

3. Call https://bonds-api.com/api/v1/latest?countries=US&maturities=10Y&api_key=YOUR_KEY

4. Render rates.US_10Y. Cache to the daily publication cadence so a dashboard refresh does not burn the 1,000 Starter calls.

Support: [email protected].

FAQ: US 10Y Treasury yield API

What is US_10Y?

US_10Y is the 10-year US Treasury yield in percent. German Bunds are DE_10Y, Spanish Bonos ES_10Y. The 2-year tenor is US_2Y / DE_2Y / ES_2Y.