Developers · API v1.0

KellyIQ API

The KellyIQ API works out how much to stake on each bet in a slate. You send the bets you have chosen, their odds, and how strongly you rate each one (or your own win probability). You get back the allocation: a dollar stake for every bet, sized across the whole slate so the bets together stay within your risk limits, plus a simulation of how that allocation could turn out.

It is the same engine as the KellyIQ app, it also has calculators for odds and single bets, and every plan includes it. Use it from scripts, notebooks, spreadsheets or your own tools.

What you can build

A few starting points. Anything that can make a web request can use it.

Size your model's bets →

Your model rates the games; one call turns its ratings into stakes for the whole slate.

Size a spreadsheet slate →

Keep your slate in a spreadsheet, export it as CSV, and get a CSV of stakes back.

Add sizing to your app →

Put the same slate sizing as the KellyIQ app inside your own tool or dashboard.

Use it from an AI assistant →

Connect Claude Code, Cursor, VS Code or Gemini CLI over MCP, and your assistant sizes slates as one of its tools.

Get started

Optimizing needs a KellyIQ account and an API key. Your daily allowance follows your plan, and the free plan includes one.

Step 1

Create a free account →

No credit card. Already have one? Go to step 2.

Step 2

Create your API key →

In Settings → API, accept the API terms and create the key. It is shown once.

Step 3

Make your first call →

The quickstart takes about five minutes.

What you can do

Endpoint	What it does	Daily limit
POST /v1/optimize	Size a slate: the allocation (a stake for every bet), each bet's fair probability and edge, and the risk of the allocation and of full, half and quarter Kelly.	Yes
POST /v1/implied-probability	The win probability a price implies, and its decimal odds.	No
POST /v1/devig	Fair probabilities for a market, with the bookmaker's margin removed.	No
POST /v1/kelly	The Kelly stake for a single bet on its own.	No
GET /v1/sports	The sports you can optimize, and the key to send for each.	No
GET /v1/me	Your plan, today's usage and the settings optimize will use.	No

The basics

Base URL https://api.kellyiq.com. JSON in, JSON out.
Authenticate with your API key: Authorization: Bearer kiqa_…. Create it in the app under Settings → API.
Daily allowances by plan: Free 10, Bettor 50, Sharp 250, Pro 500 optimizes. Calculators have no daily limit. See Limits.
The full machine-readable spec: openapi-v1.yaml (OpenAPI 3.1).

What it is, and isn’t

KellyIQ sizes the bets you choose, using the probabilities you supply or derive from the market. It does not pick bets or predict outcomes, and results are calculations, not betting advice. Use of the API is covered by the Terms of Service, section 6.5.

Support

Email support@kellyiq.com. Include the requestId from the error, or the X-Request-Id header, and we can find the exact request. If the API is having a problem, a notice appears at the top of these pages.