{"uid":"cap_fO4JZdUyEVvsRrNs-rx2n","slug":"hars-zero-signal-api-live-fx-rate-lookup-0c7ebfa8","name":"HARS-Zero Signal API – Live FX Rate Lookup","description":"Utility API for AI agents — fetch URLs, extract structured HTML,\nsummarize text, get live FX rates, and geocode addresses. Pay per call\nin USDC on Base or Solana via x402. No API keys, no subscriptions.\nSub-cent pricing optimized for high-volume agent loops.","url":"https://hars.cryptotavern.xyz/paid/fx","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["as_of","from","to","rate"],"properties":{"to":{"type":"string"},"from":{"type":"string"},"rate":{"type":"number"},"as_of":{"type":"string","format":"date-time","description":"RFC3339 timestamp"},"risks":{"type":"array","items":{"type":"string"}},"amount":{"type":"number"},"source":{"type":"string"},"product":{"type":"string"},"evidence":{"type":"array","items":{"type":"string","format":"uri"},"description":"Polymarket order book / event / reference URLs"},"sparkline":{"type":"array","items":{"type":"number"}},"confidence":{"type":"number","maximum":1,"minimum":0,"description":"Model confidence 0.0-1.0"},"market_ids":{"type":"array","items":{"type":"string"},"description":"Polymarket slugs or ids referenced in this response"},"inverse_rate":{"type":"number"},"converted_amount":{"type":"number"},"next_best_action":{"type":"object","properties":{"why":{"type":"string"},"endpoint":{"type":"string"},"price_usd":{"type":"number"},"product_id":{"type":"string"}}}},"description":"Currency pair -> live FX rate + 24h sparkline."},"responseSchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["as_of","from","to","rate"],"properties":{"to":{"type":"string"},"from":{"type":"string"},"rate":{"type":"number"},"as_of":{"type":"string","format":"date-time","description":"RFC3339 timestamp"},"risks":{"type":"array","items":{"type":"string"}},"amount":{"type":"number"},"source":{"type":"string"},"product":{"type":"string"},"evidence":{"type":"array","items":{"type":"string","format":"uri"},"description":"Polymarket order book / event / reference URLs"},"sparkline":{"type":"array","items":{"type":"number"}},"confidence":{"type":"number","maximum":1,"minimum":0,"description":"Model confidence 0.0-1.0"},"market_ids":{"type":"array","items":{"type":"string"},"description":"Polymarket slugs or ids referenced in this response"},"inverse_rate":{"type":"number"},"converted_amount":{"type":"number"},"next_best_action":{"type":"object","properties":{"why":{"type":"string"},"endpoint":{"type":"string"},"price_usd":{"type":"number"},"product_id":{"type":"string"}}}},"description":"Currency pair -> live FX rate + 24h sparkline."},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","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":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_U9C81DaakCz9e6Bar-Ab0","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns a live foreign exchange rate for a currency pair, including a 24-hour sparkline, confidence score, and inverse rate, paid per call in USDC via x402.","exampleAgentPrompt":"What's the live exchange rate from USD to EUR right now, and can you show me how the rate has trended over the last 24 hours?","exampleUseCases":[{"title":"Real-time currency conversion for invoicing","prompt":"I need to invoice a client in Japan — what's the live JPY to USD rate right now so I can convert the 250,000 JPY amount correctly?"},{"title":"FX trend check before a wire transfer","prompt":"Before I send €10,000 to a UK account, can you check the live EUR to GBP rate and show me the 24-hour sparkline so I know if the rate has moved a lot today?"},{"title":"Multi-currency portfolio monitoring","prompt":"Get me the current exchange rates from USD to CAD, AUD, and CHF, including confidence scores and any risks flagged for each pair."}],"resultDescription":"Returns a JSON object with the from/to currency codes, the live exchange rate as a float, the inverse rate, an RFC3339 timestamp for the rate, an optional 24-hour sparkline array of prices, a confidence score (0–1), a list of risk factors, evidence URLs (e.g. Polymarket reference links), the converted amount if an input amount was provided, and an optional next_best_action suggestion for follow-up calls.","failureModes":["Unsupported or malformed currency codes return an error or empty rate","Payment failure via x402 (insufficient USDC balance or unsupported chain) results in a 402 response with no data","Stale or low-confidence rates may be returned during market closure or data source outages, indicated by a low confidence score","Missing required 'from' or 'to' parameters cause a validation error"],"whenToPreferThis":"Choose this endpoint when your agent needs a live, pay-per-call FX rate with no API key setup, especially in high-volume loops where sub-cent per-call pricing matters. It is ideal for autonomous agents that already use x402/USDC micropayments on Base or Solana, and need a 24-hour sparkline or confidence score alongside the raw rate rather than a bare number from a free tier.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T12:42:53.452Z","isFirstParty":false}