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Delx Kelly Binary Calculator
x402
Delx Kelly Binary Calculator is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).
Computes the Kelly Criterion fraction for a binary bet given the true probability and market price
Price / call$0.001
Success—
StatusUnknown
How this service works
Kelly fraction for a binary market given edge and price. Call when sizing prediction-market bets with Kelly under your true_prob. Returns Kelly fraction for binary price as deterministic JSON for $0.001 USDC via x402 on Base. First-party local math only—no RPC, live market feed, API keys, storage, or mediagen. Advisory only; the caller owns capital, risk, and production controls.
Output
Returns a JSON object containing the Kelly fraction (a number between 0 and 1 representing the optimal proportion of bankroll to wager), along with the schema identifier, the input true_prob, and the input market_price echoed back for confirmation.
Example use cases
Prediction market position sizing
“I believe there's a 70% chance this prediction market resolves YES but it's trading at 55 cents — use Kelly to tell me what fraction of my bankroll I should put in.”
Sports betting edge allocation
“I've estimated a 65% true probability for this match outcome and the sportsbook is offering implied odds of 50% — what does the Kelly criterion say my optimal bet fraction is?”
Algorithmic trading signal sizing
“My model gives a 58% true probability that this binary event fires, and the current market price is 0.40 — can you compute the Kelly fraction so I can size my position correctly?”
Technical details
Endpoint
POSThttps://api.delx.ai/api/v1/x402/kelly-binaryWhen to prefer
Use this endpoint when you need a fast, stateless computation of the Kelly Criterion fraction for a binary outcome and you already have both a true probability estimate and a market price. Prefer this over building your own Kelly formula when you want a reliable, versioned, schema-tagged microservice result that is easy to audit. It is ideal for agents operating in prediction markets, sports betting, or binary options where position sizing discipline matters.
Side effects
- Missing required fields (true_prob or market_price) returns a validation error
- market_price of 0 or 1 may cause division errors or undefined Kelly fractions
- Negative Kelly fraction (when market price exceeds true probability) indicates no edge — agent should interpret as 'do not bet'
- Non-numeric inputs for true_prob or market_price will be rejected
- Values outside [0,1] for probabilities may produce meaningless results
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| true_prob | number | Input field: true prob. |
| market_price | number | Input field: market price. |
Output
Schema · Response
{
"type": "json",
"example": {
"kelly": 0.2727272727272727,
"schema": "delx/util-kelly-binary/v1",
"true_prob": 0.6,
"market_price": 0.45
}
}Tags
x402
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