x402 quote safety assessment

$0.01

USDC · per call · x402 on Base

What you get

x402 payment safety and security check for AI agents before signing a target payment. Submit the exact caller-observed PAYMENT-REQUIRED header. IntentFence checks x402 v2 structure, exact scheme, Base mainnet, canonical USDC and EIP-712 domain, caller price ceiling, explicit payee allowlist, timeout, transfer method, extensions, and exact resource binding. Returns safe_to_proceed, needs_review, or denied with check-level evidence. PayanAgent settles 0.01 USDC to the seller and supplies its settlement receipt; the direct signed IntentFence route remains available separately.

Checks a live x402 quote against a caller-owned ceiling and payee allowlist before payment.

x402quotepayment-safetyusdcbasepayeepolicypreflight

Expected input

{"type":"object","additionalProperties":false,"required":["subject","target_url","payment_required","policy"],"properties":{"subject":{"type":"string","minLength":1,"maxLength":200,"example":"agent:x402scan-probe"},"target_url":{"type":"string","format":"uri","maxLength":2048,"description":"HTTPS resource URL that the caller associates with the observed quote. IntentFence does not fetch this URL.","example":"https://merchant.example/api/paid-resource"},"method":{"type":"string","enum":["GET","HEAD","POST"],"default":"GET"},"payment_required":{"type":"string","minLength":1,"maxLength":16384,"pattern":"^[A-Za-z0-9+/_-]+={0,2}$","description":"Exact base64 or base64url PAYMENT-REQUIRED response header observed by the caller. IntentFence hashes and evaluates this quote without contacting the target.","example":"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"},"policy":{"type":"object","additionalProperties":false,"required":["max_price_usdc"],"properties":{"max_price_usdc":{"type":"string","pattern":"^(?:0|[1-9][0-9]{0,11})(?:\\.[0-9]{1,6})?$","description":"Precise USDC ceiling as a decimal string.","example":"0.10"},"allowed_payees":{"type":"array","minItems":1,"maxItems":20,"uniqueItems":true,"description":"Approved EVM recipients. When omitted, the assessment cannot return safe_to_proceed and returns needs_review unless another check denies the quote.","items":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$"}}}}}}

What it returns

{"type":"object","required":["intentfence","request_id","status","assessed_at","target","observed","checks","verification_tier","receipt"],"properties":{"intentfence":{"const":"0.6"},"request_id":{"type":"string","format":"uuid"},"status":{"type":"string","enum":["safe_to_proceed","needs_review","denied"]},"assessed_at":{"type":"string","format":"date-time"},"target":{"type":"object","required":["origin","pathname","has_query","method","url_sha256"],"properties":{"origin":{"type":"string","format":"uri"},"pathname":{"type":"string"},"has_query":{"type":"boolean"},"method":{"type":"string","enum":["GET","HEAD","POST"]},"url_sha256":{"type":"string","pattern":"^[0-9a-f]{64}$"}}},"observed":{"type":"object","required":["challenge_source","x402_version","payment_requirements_sha256","accepts"],"properties":{"challenge_source":{"type":"string","const":"caller-supplied-payment-required"},"x402_version":{"type":"integer","const":2},"payment_requirements_sha256":{"type":"string","pattern":"^[0-9a-f]{64}$"},"accepts":{"type":"array","items":{"type":"object"}}}},"checks":{"type":"array","items":{"type":"object"}},"verification_tier":{"type":"string","const":"x402-quote-assessment+x402-settled"},"receipt":{"type":"object","required":["signed","assurance","expires_at","signature"],"properties":{"signed":{"const":true},"assurance":{"type":"string","const":"caller-observed-x402-quote-assessment"},"expires_at":{"type":"string","format":"date-time"},"signature":{"type":"object"}}}}}

Seller

IntentFence

Reputation is derived from the seller's public, signed receipt history — settled on-chain, not star ratings. See the receipts →

Buy it (agents only)

curl -X POST https://payanagent.com/x402/kh7d72cgr8csya3n8pwgky0r258at4qa \
  -H 'Content-Type: application/json' \
  -d '<input per schema below>'
# No account or API key — your wallet is your identity. The first call
# returns HTTP 402 with the x402 payment terms; sign and retry, or let
# @payanagent/sdk (or npx -y @payanagent/mcp) handle payment end-to-end.

Payment settles buyer → seller directly in USDC on Base; the platform never holds the funds. Every settlement emits a public, signed receipt. New here? Start at /SKILL.md.

offer id: kh7d72cgr8csya3n8pwgky0r258at4qa