Where does the interest rate data come from?
Rates are sourced from FRED (Federal Reserve Bank of St. Louis). A bundled snapshot ensures the API always returns data; live FRED data activates automatically when a FRED API key is configured.
Interest Rate API
Fed Funds + Prime
Full Treasury Curve
Trend + History
Benchmark rates. Always current.
The Federal Funds Rate, Bank Prime Rate, and the full US Treasury yield curve, every rate labeled with trend direction and 1-month and 1-year historical context.
1mo–30yr · treasury curveFed Funds · + Prime RateTrend · rising/falling/flatSnapshot · always available
Check the curve, right now.
This calls the live Interest Rate API. Switch between benchmark rates and the full Treasury yield curve — no parameters required.
Request builder
No query parameters needed.
GET /current
Snapshot or live
Every response includes data_source: snapshot when no FRED key is configured, or live when FRED_API_KEY activates real-time data — same shape either way.
Output preview
Live response from the API, plus the exact request to reproduce it.
Loading live rates...
Why Interest Rate API
Rates, curves, and trends in one call.
Fed Funds + Prime Rate
The two most-watched US central bank rates in one call, each with trend direction and historical context.
Full Treasury curve
1-month through 30-year maturities in a single ordered array, ready to plot without client-side sorting.
Trend on every rate
Each entry reports rising, falling, or flat versus one month ago, so UIs can show direction without extra math.
1-month and 1-year context
change_1m, value_1m_ago, and value_1y_ago ship on every rate for instant before/after comparisons.
Snapshot always available
A bundled snapshot guarantees a response even without upstream configuration; live FRED data activates automatically when a key is set.
Health + metrics
GET /health reports FRED and Redis configuration state; GET /metrics exposes Prometheus counters for monitoring.
/api/v1/interest-rate
Endpoints, at a glance.
Two GET endpoints, zero required parameters: /current for benchmark rates by category, /yield-curve for the full Treasury curve.
GET/api/v1/interest-rate/current
Benchmark rates
All rates by category — central_bank and treasury — with trend indicators and 1-month/1-year context. No parameters.
GET/api/v1/interest-rate/yield-curve
Treasury yield curve
Full US Treasury curve as an ordered array from 1 month to 30 years, ready for charting.
GET/health
Service health
Status, service name, version, and fred_configured / redis_configured flags.
GET/metrics
Prometheus metrics
Request counts and durations in Prometheus exposition format.
| Parameter | Type | Required | Description |
|---|---|---|---|
| (none) | — | no | Both endpoints are parameter-free. Every request returns the full rate set or curve for the current data source. |
Error reference
Only three ways this fails.
With no required parameters, most failures are auth or rate-limit related. Every error includes a correlationId for tracing.
401Unauthorized
Missing or invalid API key at the gateway. Send x-api-key or api_key with every request.
429Rate Limited
More than 120 requests in a 15-minute window per IP. Retry after the window resets.
500Internal Error
Unexpected failure with no fallback available. Include the correlationId when reporting.
Example error response
{
"error": "Too many requests from this IP, please try again later",
"retryAfter": "15 minutes"
}FAQ
API questions developers ask first.
What rates are included?
The Federal Funds Rate and Bank Prime Loan Rate under central_bank, plus the full US Treasury curve — 1, 3, and 6 month, 1, 2, 10, and 30 year — under treasury.
Does every rate include historical context?
Yes. Each rate entry has a trend (rising, falling, or flat), change_1m, value_1m_ago, and value_1y_ago so you can show direction without a second request.
Is the yield curve ready for charting?
Yes. GET /yield-curve returns an ordered array from shortest to longest maturity with maturity_years as a number, ready to plot directly.
How do I authenticate requests?
Send your Datpaq API key as an x-api-key header or an api_key query parameter. Keys are created in the Datpaq dashboard and a free tier is included.
Add benchmark rates in one request.
Fed Funds, Prime Rate, and the full Treasury curve — with trend and history baked in, no parameters required.