Fed Rate Probability API — FOMC Rate Cut / Hike Odds (FedWatch Alternative)

Get FOMC meeting rate-change probabilities as clean JSON — a FedWatch API alternative that computes rate cut / hold / hike odds for upcoming Federal Reserve meetings from 30-Day Fed Funds futures (ZQ) prices, cross-checked against Polymarket fed-rate prediction markets.

If you've searched for a fedwatch api, fed rate probability api, or fomc rate cut odds api, this actor gives you exactly that: per-meeting probabilities (p_cut_25, p_hold, p_hike_25), implied rates in basis points, and the current effective fed funds rate (EFFR), on demand.

Unofficial. Not affiliated with CME Group, CME FedWatch, the Federal Reserve, Yahoo, or Polymarket.

What you get

One dataset row per upcoming FOMC meeting per source:

{
  "meeting_date": "2026-09-16",
  "meeting_label": "Will there be no change in Fed interest rates after the September 2026 meeting?",
  "source": "polymarket",
  "p_cut_25": null,
  "p_hold": 0.455,
  "p_hike_25": null,
  "implied_rate_bps": null,
  "contract_symbol": null,
  "market_slug": "will-there-be-no-change-in-fed-interest-rates-after-the-september-2026-meeting-615",
  "current_effr": 3.63,
  "computed_at": "2026-09-03T03:03:04.650695+00:00",
  "tentative": false
}

Real rows from a test run (Sep 2026, EFFR 3.63%, target 3.50–3.75%):

meeting	source	p_cut_25	p_hold	p_hike_25
September 2026 FOMC	polymarket	0.0055	—	—
September 2026 FOMC	polymarket	—	0.455	—
September 2026 FOMC	polymarket	—	—	0.535

source: "futures" rows additionally carry implied_rate_bps and contract_symbol (e.g. ZQV26.CBT).

Methodology (honest version)

• Futures (FedWatch-style): Monthly ZQ contracts settle at 100 − average daily EFFR for the month, so implied rate = 100 − price. For a meeting month with N days and a meeting ending on day d, we solve the post-meeting rate from avg = (d/N)·r_before + ((N−d)/N)·r_after, where r_before comes from the prior clean-month contract (or current EFFR). The gap between post- and pre-meeting implied rates, divided by 25 bps, gives the probability of a single 25 bp move (clamped to [0, 1]); the remainder is p_hold. This is a simplification of CME's methodology: it assumes at most one ±25 bp move per meeting and ignores multi-step move trees.
• Polymarket: highest-volume open markets whose question/slug mention "fed" + "rate" are classified as cut / hold / hike and their Yes-price is emitted as the probability. These are real-money prediction market odds — a great sanity check on futures-derived numbers.
• EFFR & target range: pulled live from the NY Fed public API; falls back to the current_target_range input if unreachable.
• FOMC dates: 2026 dates use the official calendar; 2027 dates are approximations and marked tentative: true.
• Yahoo Finance is rate-limit-prone; the actor rotates hosts/user-agents with exponential backoff, and if futures data is unavailable it still succeeds with Polymarket rows only (a warning is logged).

Input

field	type	default	description
meetings_ahead	integer	4	How many upcoming FOMC meetings to compute
include_polymarket	boolean	true	Emit Polymarket cross-check rows
current_target_range	string	""	e.g. "3.75-4.00"; empty = auto from NY Fed

Default input {} works out of the box.

Use cases

• Rate-decision dashboards and trading models needing FOMC rate cut odds as JSON
• Newsletters / bots posting fed rate probabilities before each meeting
• Cross-checking CME FedWatch against prediction-market pricing
• Backtesting: computed_at timestamps let you snapshot odds over time

Pricing

Pay-per-event: one small charge per probability row pushed (probability-row).

Disclaimer

Data is informational only, not investment advice. Probabilities are model outputs from third-party market prices and may differ from CME FedWatch. Unofficial; not affiliated with CME Group.