Kit Rx Agent Trust: x402 Preflight, Finder & Sanctions API docs

x402 preflight (what a paid endpoint will charge, canonical USDC check, risk flags), an x402 API finder that searches public directories and live-checks results, OFAC SDN sanctions screening for crypto addresses and names, and a decoded receipt of your own x402 payment. Each call is one x402 v2 payment in USDC on Base, Polygon, Arbitrum, Avalanche or Sei; no signup or API key. Requests that fail or match nothing are not charged.

x402 payment receipt: decode the payment you sent $0.002

GET /v1/x402/receipt

Decodes the x402 v2 PAYMENT-SIGNATURE header sent with the request into a readable receipt: x402 version, scheme, CAIP-2 network and chain name, resource URL, the copied payment requirements, payer, recipient, value in atomic units and USD, USDC contract, nonce, validity window in ISO-8601 with seconds to expiry, signature length and prefix, extension keys, and pass/fail diagnostics. Computed locally, no upstream source.

x402 preflight: inspect a paid endpoint before paying $0.005

GET /v1/x402/preflight

Sends an unpaid GET to an x402 endpoint and reports what it would charge before paying: HTTP status, redirects (max 3, re-validated), v2 PAYMENT-REQUIRED header or v1 body challenge and its validity, each accepts entry (scheme, CAIP-2 network/name, atomic amount, USD for canonical USDC, asset check, payTo, timeout, EIP-712 name/version), OFAC SDN payTo screen, resource, Bazaar extension, risk flags, host context from registry RDAP (registrar, domain age) and Cloudflare DoH.

x402 finder: search paid APIs, ranked and live-checked $0.01

GET /v1/x402/find

Search and discovery of paid x402 API endpoints for a plain-language need, across Ultravioleta DAO x402 Bazaar and 402 Index directories. Dedupes by resource URL; ranks by relevance, verification, uptime, price and recency. Each result: resource URL, short description, USDC price, CAIP-2 networks, sources, verification. The top 3 GET endpoints get a live unpaid check: valid x402 402, live price, networks, canonical USDC, risk flags, OFAC SDN payTo screen, RDAP domain age.

OFAC sanctions screening: crypto wallet or name $0.01

GET /v1/compliance/sanctions

OFAC sanctions (AML/KYC) screening of a crypto wallet or a person, company, vessel or aircraft name against a dated snapshot of the U.S. Treasury SDN and non-SDN Consolidated lists. Address mode: exact match on OFAC-listed digital currency addresses (BTC, ETH/EVM, USDT, TRX, XMR, LTC, more). Name mode: fuzzy match on names and strong aliases ignoring case, accents, punctuation and word order, scored 0-100. Returns match flag, OFAC uid, type, programs, country, list date.

Kit Rx Agent Trust: x402 Preflight, Finder & Sanctions: Trust tools for paying agents: check an x402 endpoint before paying, find trusted paid APIs, screen addresses and names against OFAC sanctions, decode payment receipts, paid per call over x402. Machine-readable: OpenAPI, llms.txt, /.well-known/x402, agent skills.