{"uid":"cap_pQQFwMTJFJCI2WLtyEtE2","slug":"nexus-arbitrage-price-comparison-e202e743","name":"NEXUS Arbitrage Price Comparison","description":"Pay-per-call financial data. Streamable HTTP MCP. x402 USDC on Base. Not financial advice.","url":"https://nexus-agent-xa12.onrender.com/arb/check","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"queryParams":{"type":"object","required":[],"properties":{"markets":{"type":"string","description":"Comma-separated markets: Fed,BTC,CPI"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"markets":["Fed"],"comparisons":[{"market":"Fed","spread":27.55,"direction":"kalshi_yes_cheaper","kalshi_price":42,"polymarket_price":69.55}]}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_mgDw-KVXkTgzd-9iKj20O","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Compares prediction market prices between Kalshi and Polymarket for Fed, BTC, and CPI markets to surface arbitrage opportunities","exampleAgentPrompt":"Check if there's a price spread between Kalshi and Polymarket for Fed, BTC, and CPI markets — I want to see which platform is cheaper and by how much.","exampleUseCases":[{"title":"Spot Fed rate arbitrage opportunity","prompt":"Can you check if there's any arbitrage opportunity right now between Kalshi and Polymarket on Fed rate decision markets? I want to know which platform is pricing it lower and what the spread looks like."},{"title":"Compare BTC prediction market prices","prompt":"Which platform has better prices for BTC prediction markets right now — Kalshi or Polymarket? Show me the spread so I can decide where to put my position."},{"title":"Find CPI market mispricing","prompt":"I want to see if Kalshi and Polymarket are pricing CPI markets differently right now — pull the latest spreads and tell me if there's any meaningful mispricing I should act on."}],"resultDescription":"Returns a list of market comparisons, each with the spread amount, the direction indicating which platform (Kalshi or Polymarket) has the lower price, and the exact prices on each platform for the requested markets (Fed, BTC, CPI).","failureModes":["Invalid or unsupported market name returns an error or empty result","Payment failure via x402 USDC returns 402 status blocking data access","Service unavailable on Render cold start causes timeout or 503","Empty markets query param may return all or no markets depending on default behavior"],"whenToPreferThis":"Use this endpoint when you need real-time price spread data between Kalshi and Polymarket for Fed rate, BTC, or CPI prediction markets and want to identify arbitrage opportunities. Prefer this over general financial data APIs when the specific goal is cross-platform prediction market comparison with per-call micropayment pricing via USDC.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T18:44:15.236Z","isFirstParty":false}