{"uid":"cap_b3V-5fQyCfBaO7VtMVT_k","slug":"scrapebench-prediction-markets-api-e3e40e91","name":"Scrapebench Prediction Markets API","description":"Live Kalshi and Polymarket prediction-market odds by keyword, category or city, one schema for both venues, with the price spread when the same question trades on both. Snapshot refreshed hourly from the exchanges' public APIs.","url":"https://api.scrapebench.dev/v1/prediction-markets?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"sort":{"enum":["volume","close_time"],"type":"string","title":"Sort","default":"volume","description":"volume: most traded first (default); close_time: soonest to close first."},"query":{"anyOf":[{"type":"string","maxLength":100},{"type":"null"}],"title":"Query","default":null,"description":"Case-insensitive substring over question, subtitle, series, ticker, event and weather city, e.g. 'fed', 'bitcoin', 'new york'."},"venue":{"enum":["both","kalshi","polymarket"],"type":"string","title":"Venue","default":"both","description":"Which exchange to search: both (default), kalshi or polymarket."},"series":{"type":"array","items":{"type":"string","maxLength":100},"title":"Series","maxItems":20,"description":"Kalshi series tickers, e.g. 'KXHIGHNY' (NYC daily high) or 'KXFEDDECISION'."},"purpose":{"anyOf":[{"type":"string","maxLength":200},{"type":"null"}],"title":"Purpose","default":null,"description":"Optional: what you need this data for, in one sentence (e.g. 'vetting a roofer before hiring'). It never changes the price or the rows; it tells us what to improve."},"queries":{"type":"array","items":{"type":"string","maxLength":100},"title":"Queries","maxItems":20,"description":"More keywords; a market matching any of them (or query) is returned."},"categories":{"type":"array","items":{"type":"string","maxLength":100},"title":"Categories","maxItems":20,"description":"Kalshi categories, e.g. 'Economics', 'Climate and Weather'. Polymarket publishes none, so setting this returns Kalshi markets only."},"min_volume":{"type":"number","title":"Min Volume","default":0,"minimum":0,"description":"Drop markets that traded less than this (contracts on Kalshi, USD on Polymarket)."}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.06","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":"$0.06/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.06","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.06","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_PH78AFPSzzuLcD4WKPklW","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.06","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Fetches live odds from Kalshi and Polymarket prediction markets by keyword, category, or city, returning a unified schema with price spreads when the same question trades on both venues.","exampleAgentPrompt":"Pull live prediction market odds for 'Fed rate decision' from both Kalshi and Polymarket, sorted by volume, and show me the price spread if the same question trades on both venues.","exampleUseCases":[{"title":"Fed rate decision odds comparison","prompt":"What are the current Kalshi and Polymarket odds on the Fed's next interest rate decision? Show me both venues side by side and flag any price spread between them, sorted by trading volume."},{"title":"Weather event prediction markets","prompt":"Find prediction markets about New York City temperature records on Kalshi — specifically the KXHIGHNY series — and show me the ones closing soonest with at least 500 contracts traded."},{"title":"Bitcoin price prediction monitoring","prompt":"Search for all active Bitcoin prediction markets on Polymarket sorted by volume, so I can see where the crowd thinks the price is headed."}],"resultDescription":"A list of matching prediction market records in a unified schema covering both Kalshi and Polymarket, including market question, ticker, odds/prices, trading volume, close time, and venue. When the same question trades on both exchanges, a price spread field is included. Snapshot data is refreshed hourly from the exchanges' public APIs.","failureModes":["No markets match the keyword or filters — returns empty list","Invalid category name returns empty or Kalshi-only results since Polymarket has no categories","Series ticker not found on Kalshi returns no results","min_volume too high filters out all available markets","Stale data if the hourly snapshot has not yet refreshed since a market closed","Rate limit or payment failure if x402 USDC payment is not properly handled"],"whenToPreferThis":"Use this endpoint when you need a unified view of prediction market odds across both Kalshi and Polymarket without building separate integrations for each exchange. It is especially valuable when comparing price spreads between venues for the same question, or when filtering by Kalshi-specific constructs like series tickers or categories. Prefer this over direct exchange APIs when you want normalized, comparable data in one schema with minimal overhead.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-21T13:29:27.336Z","isFirstParty":false,"canonicalSlug":"scrapebench-prediction-markets-api-e3e40e91"}