{"slug":"goodsong-dev-verify-seller-dabd05","title":"Verify an x402 seller before paying it","host":"goodsong.dev","method":"POST","resource":"https://goodsong.dev/verify/seller","category":"company","description":"Verify an x402 seller before paying it: does it exist and respond with a well-formed 402 challenge, is its own declared input/output schema internally consistent, and is its payout address sanctioned? Checked live against the seller itself plus Chainalysis's sanctions oracle and Blockscout (Base pay","price_listed":0.005,"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":2,"reported_payers_30d":1,"networks":["eip155:8453"],"badge":"unverified","paid_checks_7d":0,"paid_ok_7d":0,"example_input":{"body":{"method":"POST","resource_url":"https://api.example.com/paid-endpoint"},"bodyType":"json","method":"POST","type":"http"},"output_schema":{"$schema":"https://json-schema.org/draft/2020-12/schema","properties":{"input":{"additionalProperties":false,"properties":{"body":{"description":"Provide the exact x402 resource URL; method defaults to POST.","properties":{"method":{"description":"HTTP method that triggers the seller's 402 challenge.","enum":["GET","POST"],"type":"string"},"resource_url":{"description":"The x402 resource URL to verify.","type":"string"}},"required":["resource_url"]},"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":{"canonical":{"type":["object","null"]},"checks":{"type":"object"},"cost":{"type":"object"},"evidence":{"type":"array"},"latency_ms":{"type":"integer"},"verdict":{"enum":["confirmed","contradicted","unknown"],"type":"string"}},"type":"object"},"type":{"type":"string"}},"required":["type"],"type":"object"}},"required":["input"],"type":"object"},"history":[],"description_full":"Verify an x402 seller before paying it: does it exist and respond with a well-formed 402 challenge, is its own declared input/output schema internally consistent, and is its payout address sanctioned? Checked live against the seller itself plus Chainalysis's sanctions oracle and Blockscout (Base payTo addresses only). Confirms the checkable things about a seller check out -- not a guarantee of trustworthiness, which no free source can promise.","last_updated":"2026-09-04T01:27:33.567Z","schemes":["exact"]}