Programmatic Access to the Yield Curve

Every chart on yieldcurve.pro is backed by a query. Now you can run those queries yourself.

We shipped a REST API covering the same data that powers the site: daily Treasury yields (all 13 tenors, back to 2001), auction results and grades, implied forward and spot curves, ACM term premia, regime classifications, and FOMC rate decisions. JSON in, JSON out, no screen-scraping required.

Getting Started

Generate a Bearer token from your Account Dashboard. The token starts with ycp_ and shows once — copy it or lose it. Every request includes it in the Authorization header:

GET /api/v1/curves
Authorization: Bearer ycp_abc123...

The base URL is https://www.yieldcurve.pro/api/v1. Full documentation lives at /api.

What's Available

Nine data endpoints, each mirroring a page on the site:

• /curves — Single-date yield curve snapshot across all 13 tenors, from 1 Mo to 30 Yr
• /levels — Time series of yields at selected tenors. Filter by tenor: ?tenors=2+Yr&tenors=10+Yr
• /slopes — Spread between any two tenors over time. Default is the 10Y-3Mo
• /forwards — Par, spot, and implied forward curves for a given date and horizon
• /premia — ACM term premium and risk-neutral yield decomposition by tenor
• /regimes — Bull/Bear Steep/Flat classification with level-slope-twist components and configurable lookback window
• /auctions — Graded auction results: bid-to-cover, tails, bidder allocations, letter grades (A through D based on historical percentiles)
• /fed — FOMC rate decisions with target range and change in basis points
• /usage — Your current daily usage and remaining requests per endpoint

Plus a /health endpoint (no auth) for monitoring.

Response Format

Every endpoint returns the same envelope:

{
  "data": [...],
  "count": 252,
  "endpoint": "levels"
}

Dates default to the trailing year if omitted. NaN values serialize as null. Floats round to 6 decimal places. Rate limit headers (X-RateLimit-Limit, X-RateLimit-Remaining) ship with every response so you always know where you stand.

Rate Limits

Three tiers, reset at midnight UTC:

The free tier ships with every account. Enough to prototype a model, test an integration, or pull a daily snapshot. Basic and Pro are for production workloads.

What You Can Build

The API returns the same data practitioners look at on the site, in a format machines can consume. A few starting points:

• Daily data pipelines — Pull the latest curve, spreads, and auction grades into your own database or spreadsheet
• Screening and alerts — Monitor regime changes, spread thresholds, or auction quality programmatically
• Backtesting — Feed historical yields, term premia, and regime labels into your models
• Dashboards — Build custom views combining yieldcurve.pro data with your proprietary analytics

Try It

If you have an account, you already have API access. Generate a token, hit /api/v1/curves, and see what comes back. The documentation has the full parameter reference for every endpoint.