# Base Pay-To Address Screen

> Base Pay-To Address Screen is a paid API for AI agents from api.x402risk.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-02).

Screens a Base (EVM) address against OFAC SDN sanctions, detects address-poisoning lookalikes, checks contract vs EOA status, and returns a block/caution/ok verdict with labels and risk reasons.

## Facts

- Endpoint: POST https://api.x402risk.com/v1/address-screen?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-pay-to-address-screen-72d74a6d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_RDjrxgztVlDQ7x9CORpA9

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability base-pay-to-address-screen-72d74a6d -d '<json body>'
```

Example prompt: Before I send funds, screen the Base address 0x098B716B8Aaf21512996dC57EB0615e2383E2f96 against OFAC sanctions and check if it looks like a lookalike of my intended recipient 0xAbCd1234567890abcdef1234567890abcdef1234 — give me the verdict.

## When to prefer this

Use this endpoint when you need fast, pay-per-call OFAC SDN screening of a specific Base (chain 8453) EVM address before executing a payment or trade, especially when you also want address-poisoning detection, contract/EOA classification, and labels — all in one call for $0.005 USDC. Prefer it over generic blockchain explorers when you need a structured, machine-readable compliance verdict with sanctions list metadata rather than a manual lookup.

## Known failure modes

- Invalid address format (not a valid 0x EVM address) returns a validation error
- Address not yet indexed on Blockscout may result in incomplete activity data with first_seen_is_lower_bound=true
- OFAC SDN list may lag real-world updates by up to one day due to daily refresh cycle
- compare_to address that is itself malformed causes lookalike check to fail
- Network or RPC errors may result in partial source data with errors array populated
- Payment failure (insufficient USDC or x402 protocol error) prevents the call from completing

## How this service works

Pay-to / counterparty address screen for Base: exact match against OFAC SDN published digital currency addresses (daily refresh, list date included), contract vs EOA, Blockscout verification, first-seen age and tx count, lookalike (address-poisoning) check vs an optional compare_to, labels, and a block/caution/ok verdict. $0.005 USDC. Screening aid only, not a compliance clearance or legal advice.

## Output

Returns a JSON object with a verdict field (block, caution, or ok), sanctions match details including SDN name/program/list date, contract vs EOA classification, address activity stats (tx count, first-seen age), lookalike detection result vs compare_to, address labels, data sources used, and a disclaimer. A 'block' verdict means an exact OFAC SDN match was found.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "address": {
   "type": "string",
   "pattern": "^0x[0-9a-fA-F]{40}$",
   "description": "EVM address to screen (Base, chain 8453)"
  },
  "compare_to": {
   "type": "string",
   "pattern": "^0x[0-9a-fA-F]{40}$",
   "description": "Optional intended recipient address; flags a lookalike (address-poisoning) match"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "chain": "base",
  "cached": false,
  "errors": [],
  "labels": [],
  "status": "ok",
  "address": "0x098B716B8Aaf21512996dC57EB0615e2383E2f96",
  "product": "address-screen",
  "reasons": [
   "exact match to an OFAC SDN digital currency address (LAZARUS GROUP; list date 2026-09-23)"
  ],
  "sources": [
   "ofac-sdn",
   "base-rpc",
   "blockscout"
  ],
  "verdict": "block",
  "activity": {
   "tx_count_indexed": 0,
   "outgoing_tx_count": 0,
   "first_seen_age_days": 798.4,
   "first_seen_is_lower_bound": false
  },
  "chain_id": 8453,
  "contract": null,
  "lookalike": null,
  "sanctions": {
   "list": "OFAC SDN (Specially Designated Nationals) - digital currency addresses",
   "matches": [
    {
     "sdn_uid": "23036",
     "programs": [
      "DPRK3"
     ],
     "sdn_name": "LAZARUS GROUP",
     "sdn_type": "Entity",
     "currency_tag": "ETH"
    }
   ],
   "list_date": "2026-09-23",
   "sanctioned": true
  },
  "disclaimer": "Screening aid only, not a compliance clearance or legal advice. Sanctions result is an exact match against EVM-format digital currency addresses published in the OFAC SDN list as of list_date; a non-match does not mean an address or its owner is not sanctioned or is safe. On-chain facts and labels come from public sources and can be incomplete.",
  "sanctioned": true,
  "is_contract": false,
  "block_number": 35000000,
  "schema_version": "1.0",
  "eip7702_delegated_eoa": false
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-pay-to-address-screen-72d74a6d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.x402risk.com](https://www.zero.xyz/host/api.x402risk.com/llms.txt)