Guides · API

Should my agent pay this x402 seller? Reads the seller's 402, screens its payTo wallets against OFAC, checks domain age, uptime and optionally the company behind it: allow, review or deny.

Use before an agent pays an x402 endpoint it has not used before: reads the seller's own 402 challenge, screens every payTo wallet against the OFAC list, checks the domain (age, setup), Factline's daily uptime probes and, with company, the register record and EU/UN/UK/US sanctions. Returns allow, review or deny, plus a trust-provider block (decision, score, evidence, ttl). Input: url, optional wallet, company, country.

0.01 USDC per call · GET /v1/payee/check · free preview at /v1/payee/check/preview

Parameters

Name	Required	Description
`url`	no	The x402 endpoint (or origin) you are about to pay, e.g. https://factline.dev/v1/kyb/check
`wallet`	no	Optional payTo wallet address to screen (read from the endpoint's 402 when url is given)
`company`	no	Optional company behind the seller: adds the register record and a sanctions screen of the company
`country`	no	Optional ISO country of that company, e.g. GB

Example request

curl "https://factline.dev/v1/payee/check?url=https%3A%2F%2Ffactline.dev%2Fv1%2Fkyb%2Fcheck"
# 402 Payment Required: pay with an x402 client (USDC on Base or Solana), or send
# Authorization: Bearer <your Factline API key>

Example response

{
  "decision": "allow",
  "score": 100,
  "flags": [],
  "seller": {
    "origin": "https://factline.dev",
    "x402": {
      "networks": [
        "eip155:8453",
        "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp"
      ],
      "payment_options": [
        {
          "network": "eip155:8453",
          "pay_to": "0xb58dd178abac67f6d4894437a7fc725cbddb2075",
          "amount": "50000",
          "scheme": "exact"
        }
      ]
    },
    "domain": {
      "registered": "2026-09-16",
      "flags": []
    },
    "health": {
      "checked_days": 30,
      "ok_rate": 1,
      "median_ms": 420
    }
  },
  "wallets": [
    {
      "wallet": "0xb58dd178abac67f6d4894437a7fc725cbddb2075",
      "sanctioned": false,
      "matches": []
    }
  ],
  "company": "not requested (send company and country)",
  "trust": {
    "decision": "allow",
    "score": 100,
    "evidence": "https://factline.dev/v1/payee/check?url=https%3A%2F%2Ffactline.dev%2Fv1%2Fkyb%2Fcheck",
    "ttl": 3600
  }
}

Use it from an AI agent

Agents with an x402 wallet call the URL directly and pay per request. Assistants that speak MCP connect to https://factline.dev/mcp. Full reference: docs, OpenAPI, llms.txt. Businesses: API keys with a free trial.

Questions

How much does the Should my agent pay this x402 seller? Reads the seller's 402, screens its payTo wallets against OFAC, checks domain age, uptime and optionally the company behind it: allow, review or deny. cost?

0.01 USDC per call, paid per request with x402 (no account), or included in a Factline API key plan with a free trial. Calls that fail are not charged.

Can I try it for free?

Yes: GET /v1/payee/check/preview with the same parameters validates your input and shows what the paid answer contains, at no cost.

Where does the data come from?

Official public registers and open data, named with their licence in every response (source field) and at /.well-known/x402-license-provenance.