{"slug":"agents-supremeai-ca-v1-preflight-7c2edc","title":"Check an x402 endpoint BEFORE paying it","host":"agents.supremeai.ca","method":"POST","resource":"https://agents.supremeai.ca/v1/preflight","category":"market","description":"Check an x402 endpoint BEFORE paying it. Makes one unpaid request (never sends money), decodes the 402 terms, and verifies: the asset is a real USD stablecoin on that network, the price in USD vs your max_price_usd cap (default $0.50), payTo is a sane address (and matches expected_pay_to if given), ","price_listed":0.01,"price_asked":null,"state":"effects","state_label":"Not tested: has real-world effects","checks_7d":0,"answered_7d":0,"latency_ms_median":null,"reported_calls_30d":1,"reported_payers_30d":1,"networks":["eip155:8453"],"badge":"unverified","paid_checks_7d":0,"paid_ok_7d":0,"example_input":{"body":{"max_price_usd":0.05,"url":"https://agents.supremeai.ca/v1/validate"},"bodyType":"json","method":"POST","type":"http"},"output_schema":{"$schema":"https://json-schema.org/draft/2020-12/schema","properties":{"input":{"additionalProperties":false,"properties":{"body":{"properties":{"body":{"description":"JSON body to send with POST probes","type":"object"},"expected_pay_to":{"description":"wallet you expect to be paid","type":"string"},"max_price_usd":{"description":"highest acceptable price, default 0.50","type":"number"},"method":{"description":"GET or POST; default tries GET then POST","type":"string"},"url":{"description":"x402 endpoint you intend to pay","type":"string"}},"required":["url"],"type":"object"},"bodyType":{"enum":["json","form-data","text"],"type":"string"},"method":{"enum":["POST","PUT","PATCH"],"type":"string"},"type":{"const":"http","type":"string"}},"required":["type","method","bodyType","body"],"type":"object"},"output":{"properties":{"example":{"properties":{"checks":{"type":"object"},"findings":{"type":"array"},"payment_options":{"type":"array"},"recommended_option":{"type":["integer","null"]},"risk":{"enum":["low","medium","high","unknown"],"type":"string"},"safe_to_pay":{"type":["boolean","null"]},"summary":{"type":"string"}},"type":"object"},"type":{"type":"string"}},"required":["type"],"type":"object"}},"required":["input"],"type":"object"},"history":[],"description_full":"Check an x402 endpoint BEFORE paying it. Makes one unpaid request (never sends money), decodes the 402 terms, and verifies: the asset is a real USD stablecoin on that network, the price in USD vs your max_price_usd cap (default $0.50), payTo is a sane address (and matches expected_pay_to if given), HTTPS and certificate validity, redirects, and domain age. Returns safe_to_pay, a risk level, findings, and the cheapest acceptable payment option.","last_updated":"2026-10-23T15:01:58.111Z","schemes":["exact"]}