{"uid":"cap_BM6KPbKX0PQSxWYJla17L","slug":"delx-kelly-binary-calculator-817016c5","name":"Delx Kelly Binary Calculator","description":"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.","url":"https://api.delx.ai/api/v1/x402/kelly-binary","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"true_prob":{"type":"number","description":"Input field: true prob."},"market_price":{"type":"number","description":"Input field: market price."}}},"responseSchema":{"type":"json","example":{"kelly":0.2727272727272727,"schema":"delx/util-kelly-binary/v1","true_prob":0.6,"market_price":0.45}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_xae_wnOMbCG8AWn4EjrEw","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes the Kelly Criterion fraction for a binary bet given the true probability and market price","exampleAgentPrompt":"I think the true probability of this outcome is 60% but the market is pricing it at 45% — what fraction of my bankroll does Kelly say I should wager?","exampleUseCases":[{"title":"Prediction market position sizing","prompt":"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."},{"title":"Sports betting edge allocation","prompt":"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?"},{"title":"Algorithmic trading signal sizing","prompt":"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?"}],"resultDescription":"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.","failureModes":["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"],"whenToPreferThis":"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.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T19:01:19.068Z","isFirstParty":false}