{"uid":"cap_q8A1Uy-HivLNy3tE-vQcs","slug":"x402-payment-firewall-46f24c28","name":"x402 Payment Firewall","description":"Evaluate x402 payment challenges against caller-defined security policies before an AI agent signs or pays.","url":"https://x402-payment-firewall.vercel.app/api/evaluate?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":null,"responseSchema":{"type":"json","example":{"mode":"paid","decision":{"reasons":[],"decision":"allow","riskScore":0}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.1","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"settled","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":"$0.1/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_2f0xGRNsH1F4eYwIrfpFZ","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.1","costPer":"request","priority":0,"asset":null,"unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Evaluates an x402 payment challenge against caller-defined security policies to decide whether an AI agent should allow, block, or flag a payment before signing.","exampleAgentPrompt":"Before my agent signs this x402 payment challenge, run it through the payment firewall and check it against my no-single-payment-over-$10 policy — tell me the risk score and whether to allow or block it.","exampleUseCases":null,"resultDescription":"Returns a JSON object with a decision field ('allow', 'block', or 'flag'), a numeric riskScore (0-1), an array of reasons explaining the decision, and the evaluation mode ('paid' or 'free').","failureModes":["Invalid or malformed x402 challenge payload returns a 400 error","Missing or invalid policy definition causes evaluation to fail with a policy error","Payment of 0.1 USDC not fulfilled results in a 402 response before evaluation occurs","Unrecognized policy rules may be silently ignored or cause a validation error","Upstream policy engine timeout returns a 503 or degraded response"],"whenToPreferThis":"Use this endpoint when an AI agent is operating autonomously and needs a policy gate before signing or paying any x402 payment challenge — especially when you need risk scoring, auditability, or spending controls beyond simple balance checks. Prefer this over naive auto-sign logic whenever the agent may encounter untrusted or adversarial payment requests.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-11T12:36:45.565Z","isFirstParty":false,"canonicalSlug":"x402-payment-firewall-46f24c28"}