{"uid":"cap_S_YNudAJwgMTdYAHNznma","slug":"x402-payment-guard-preflight-evaluator-b7b79b72","name":"x402 Payment Guard Preflight Evaluator","description":"Machine-payable service intelligence for discovering, verifying, and monitoring identity, risk, authorization, execution-preflight, and evidence APIs before autonomous agents spend.","url":"https://base-agent-preflight.bytoken2023.workers.dev/v1/x402/payment-guard/evaluate?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["url","session_id","request_id"],"properties":{"to":{"type":"string","pattern":"^0x[a-fA-F0-9]{40}$","description":"Optional transaction destination for intent decoding."},"url":{"type":"string","pattern":"^https?://","maxLength":2048,"description":"Public x402 resource URL to evaluate before payment."},"data":{"type":"string","pattern":"^0x(?:[a-fA-F0-9]{2})*$","maxLength":8194,"description":"Optional EVM calldata."},"value":{"type":"string","pattern":"^[0-9]+$","description":"Optional native ETH value in wei."},"request_id":{"type":"string","pattern":"^[A-Za-z0-9._:-]{1,128}$","description":"Caller-defined idempotency key."},"session_id":{"type":"string","pattern":"^[A-Za-z0-9._:-]{1,96}$","description":"Caller-defined budget and audit scope."},"allow_pay_to":{"type":"string","maxLength":2048,"description":"Optional comma-separated recipient allowlist."},"block_pay_to":{"type":"string","maxLength":2048,"description":"Optional comma-separated recipient blocklist."},"max_single_usdc":{"type":"string","pattern":"^[0-9]+(?:\\.[0-9]{1,6})?$","description":"Maximum allowed price for one payment."},"daily_budget_usdc":{"type":"string","pattern":"^[0-9]+(?:\\.[0-9]{1,6})?$","description":"Maximum reserved spend for this session in one UTC day."},"session_budget_usdc":{"type":"string","pattern":"^[0-9]+(?:\\.[0-9]{1,6})?$","description":"Maximum reserved spend for this session."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","required":["product","decision","risk_score","payment","reasons"],"properties":{"budget":{"type":"object"},"policy":{"type":"object"},"payment":{"type":"object"},"product":{"type":"string"},"reasons":{"type":"array"},"decision":{"enum":["ALLOW","REVIEW","BLOCK"],"type":"string"},"evidence":{"type":"object"},"risk_score":{"type":"number"},"decision_token":{"type":"string"}}}}}}},"responseSchema":{"type":"json","example":{"policy":{"human_approval":true,"budget_enforced":true,"mandate_enforced":true,"replay_protection":true},"payment":{"pay_to":"0x94F751f04b98507D31b500b7Ed50bE68A1514873","network":"eip155:8453","amount_usdc":"0.01"},"product":"agent-payment-guard","reasons":[],"decision":"ALLOW","evidence":{"domain_risk":"low","merchant_risk":"low","transaction_simulation":"success"},"risk_score":4}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.1","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":"$0.100004/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.100004","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.100004","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_g8g2Giv7q1EXgnI_qRjP6","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.100004","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Evaluates an x402 payment URL before autonomous spending — enforcing budgets, scoring merchant/domain risk, detecting replay, and requiring human approval when needed.","exampleAgentPrompt":"Before paying, run a preflight check on https://api.example.com/report.pdf — use session ID 'sess-abc123' and request ID 'req-001', cap any single payment at 0.50 USDC and the daily budget at 5.00 USDC, and block payments to 0xDeAdBeEf0000000000000000000000000000dEaD.","exampleUseCases":null,"resultDescription":"Returns a structured decision object containing: a pay/block/hold decision, a risk score for the merchant and domain, payment details parsed from the x402 resource, budget reservation status, policy compliance results, and human-readable reasons explaining the outcome.","failureModes":["Missing required query params (url, session_id, request_id) returns 400 validation error","Budget already exhausted for session returns block decision","Recipient address on blocklist returns block decision with reason","Domain risk score too high triggers hold/human-approval decision","Replayed request_id within session returns replay-detected error","Invalid URL format or non-https URL rejected by schema validation","x402 resource unreachable or returns non-402 response causes evaluation failure"],"whenToPreferThis":"Use this endpoint whenever an AI agent is about to autonomously execute an x402 USDC payment and you need to enforce budget caps, block/allow specific recipients, detect replay attacks, score merchant risk, or gate spending on human approval — especially on Base/EVM chains. Prefer this over direct payment execution when operating in autonomous or semi-autonomous agentic workflows where financial guardrails are required.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-10T18:44:25.297Z","isFirstParty":false,"canonicalSlug":"x402-payment-guard-preflight-evaluator-b7b79b72"}