{"uid":"cap_aHYPONytkOaudVwbPxCWf","slug":"intentfence-x402-quote-verifier-e39a3234","name":"IntentFence x402 Quote Verifier","description":"Fail-closed, action-bound authorization for AI agents with five-minute ES256 receipts, MCP risk scanning, and x402 payment safety.","url":"https://agentpass-protocol.rmalka06.chatgpt.site/api/x402-readiness?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"body":{"description":"Optional JSON request body for POST probes, limited to 4096 encoded bytes."},"method":{"enum":["GET","HEAD","POST"],"type":"string","default":"GET"},"policy":{"type":"object","required":["max_price_usdc"],"deprecated":true,"properties":{"allowed_payees":{"type":"array","items":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$"},"maxItems":20,"minItems":1,"description":"Optional explicit payee allowlist. Omission yields ready_with_review for an otherwise valid quote.","uniqueItems":true},"max_price_usdc":{"type":"string","pattern":"^(?:0|[1-9][0-9]{0,11})(?:\\.[0-9]{1,6})?$","description":"Maximum acceptable x402 price in USDC."}},"description":"Legacy nested policy input. New buyers should use the optional top-level fields.","additionalProperties":false},"subject":{"type":"string","default":"agent:anonymous-marketplace-buyer","maxLength":200,"minLength":1,"description":"Optional buyer identifier. Omit for anonymous marketplace delivery."},"target_url":{"type":"string","format":"uri","maxLength":2048,"description":"Public HTTPS x402 resource URL on the standard HTTPS port."},"allowed_payees":{"type":"array","items":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$"},"maxItems":20,"minItems":1,"description":"Optional explicit payee allowlist. Omission yields ready_with_review for an otherwise valid quote.","uniqueItems":true},"max_price_usdc":{"type":"string","default":"1.00","pattern":"^(?:0|[1-9][0-9]{0,11})(?:\\.[0-9]{1,6})?$","description":"Optional maximum acceptable x402 price in USDC."}}},"responseSchema":{"type":"json","example":{"status":"ready","receipt":{"signed":true,"assurance":"live-x402-endpoint-readiness"},"observed":{"http_status":402,"redirect_blocked":false,"payment_required_present":true},"request_id":"7d7fbf44-3c39-4eca-89d6-b44d756c8df1","intentfence":"0.9","verification_tier":"live-x402-readiness+x402-settled"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","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":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_6JkNHh8RQLPPhjUTSdrFP","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Probes a target x402-gated URL and verifies whether the payment quote is safe to pay — checking asset type, price ceiling, payee address, and resource binding before an agent commits funds.","exampleAgentPrompt":"Before paying for that x402-gated API at https://data.example.com/report, check that the price is under $0.10 USDC, the asset is Base USDC, and the payee is 0xAbC1234...def5678 — give me a readiness verdict so I know it's safe to proceed.","exampleUseCases":[{"title":"Pre-payment safety check for autonomous agent","prompt":"My agent is about to pay an x402 endpoint at https://api.weatherservice.io/premium-forecast — before it spends any USDC, verify that the quoted price is under $0.05, the payee is 0x1234567890abcdef1234567890abcdef12345678, and it's genuinely a Base USDC charge. Give me a green light or flag it."},{"title":"Enforce price ceiling across marketplace APIs","prompt":"I'm integrating with a third-party x402 API at https://marketplace.example.com/data/prices and I need you to check that they won't charge more than $0.50 USDC per call — probe the endpoint and tell me if it passes my max price policy."},{"title":"Detect redirect or spoofing risk before payment","prompt":"Can you check whether https://pay.suspiciousapi.xyz/premium actually presents a proper x402 payment challenge without any redirect tricks, and tell me the intentfence confidence score so I can decide whether to trust it?"}],"resultDescription":"Returns a JSON object with a 'status' field (e.g. 'ready'), an 'intentfence' confidence score (0–1), the observed HTTP status code, whether a 402 Payment Required was present and if redirects were blocked, a verification tier indicating how the assessment was performed, and a signed receipt confirming live endpoint readiness.","failureModes":["Target URL is not reachable or returns non-402 status — status reflects endpoint not x402-ready","Price exceeds max_price_usdc — returns a non-ready status flagging the price violation","Payee address not in allowed_payees allowlist — returns ready_with_review or rejected status","Target URL uses non-HTTPS or non-standard port — rejected as invalid input","Malformed payee address (not valid 0x hex) — input validation error","URL exceeds 2048 character limit — request rejected","POST body exceeds 4096 encoded bytes — input validation error"],"whenToPreferThis":"Use IntentFence when an AI agent is about to execute an x402 micropayment and needs an independent, caller-side verification that the quote is legitimate — especially when payee address whitelisting, price ceiling enforcement, or redirect-spoofing detection is required. Prefer this over blindly trusting the payment challenge returned by the target server itself.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-11T06:35:01.964Z","isFirstParty":false,"canonicalSlug":"intentfence-x402-quote-verifier-8ae2e360"}