Screen a wallet against OFAC (free, anonymous)

2026-05-27 · Docs ofac free-tier trust-check

POST /v1/trust-check/ofac returns an allow or block verdict for any wallet address, screened against the U.S. Treasury OFAC SDN list. Anonymous, free, rate-limited at 1 r/s + burst 3, refreshed daily from the Treasury XML feed.

Live status: see /health for current version, list refresh timestamp, and recent error count.

Why this vs alternatives

vs Chainalysis Sanctions Oracle: HTTP + JSON instead of an on-chain contract call. No RPC dependency, no chain-specific deploys, works from any backend or non-EVM context. Sub-second response latency.
vs rolling your own from the Treasury XML feed: save the parse-refresh-cache infrastructure. The underlying source is public at treasury.gov/ofac/downloads/sdn.xml if you ever want to migrate off this endpoint.
vs paid-tier API services (~$200-500/mo): free at this scope. Pay only when you need token-contract risk via /v1/trust-check ($0.001/call x402).

cURL

curl -X POST https://swap.paladinfi.com/v1/trust-check/ofac \
  -H "content-type: application/json" \
  -d '{"address":"0x0000000000000000000000000000000000000000"}'

Allow response (full live shape):

{
  "address": "0x0000000000000000000000000000000000000000",
  "chainId": 8453,
  "trust": {
    "recommendation": "allow",
    "factors": [
      {"source":"ofac","signal":"not_listed","weight":0,"details":"","real":true}
    ],
    "version": "1.1",
    "_real": true,
    "_scope": "ofac-only (wallet-address screen; use /v1/trust-check for full composition: GoPlus + Etherscan + anomaly heuristics)",
    "_ofac_list_updated_at": "2026-05-27T04:07:49Z",
    "_ofac_sdn_count": 93
  },
  "_paid_endpoint_info": {
    "url": "https://swap.paladinfi.com/v1/trust-check",
    "method": "POST",
    "auth": "x402 (USDC EIP-3009 transferWithAuthorization on Base)",
    "price_usdc": "0.001",
    "plugins": {
      "elizaos": "https://www.npmjs.com/package/@paladinfi/eliza-plugin-trust",
      "agentkit": "https://www.npmjs.com/package/@paladinfi/agentkit-actions"
    },
    "docs": "https://paladinfi.com/trust-check/"
  }
}

Block response (sanctioned wallet — abbreviated):

{
  "trust": {
    "recommendation": "block",
    "factors": [
      {"source":"ofac","signal":"listed","weight":100,"details":"OFAC SDN listed","real":true}
    ],
    "version": "1.1",
    "_real": true
  }
}

Branch on trust.recommendation — "allow" or "block". The _real: true field is your machine-verifiable signal that this is live screening (not a fixture). The chainId: 8453 field is informational only — OFAC SDN entries are EOA addresses screened identically across chains.

Drop-in React hook

import { useEffect, useState } from "react";

export function useOfacScreen(address?: `0x${string}`) {
  const [verdict, setVerdict] = useState<"allow" | "block" | "idle" | "loading" | "error">(
    address ? "loading" : "idle"
  );
  useEffect(() => {
    if (!address) { setVerdict("idle"); return; }
    setVerdict("loading");
    const ctrl = new AbortController();
    fetch("https://swap.paladinfi.com/v1/trust-check/ofac", {
      method: "POST",
      headers: { "content-type": "application/json" },
      body: JSON.stringify({ address }),
      signal: ctrl.signal,
    })
      .then(r => r.ok ? r.json() : Promise.reject(r.status))
      .then(d => setVerdict(d.trust.recommendation === "block" ? "block" : "allow"))
      .catch(() => { if (!ctrl.signal.aborted) setVerdict("error"); });
    return () => ctrl.abort();
  }, [address]);
  return verdict;
}

Use in a wallet-gate (fail-closed default for compliance use):

const verdict = useOfacScreen(connectedAddress);
// Fail-closed: block on error or while loading. Required for compliance use.
if (verdict === "block" || verdict === "error" || verdict === "loading") {
  return <SanctionsBlockedMessage />; // replace with your component
}
// Fail-open is appropriate only for non-compliance UX gates where false-blocks
// cost more than false-allows.

When you need more

For token-contract risk (proxy detection, holder concentration, mint authority, transfer hooks, recently-deployed flag, multi-source composition with fail-closed contract), use the paid /v1/trust-check endpoint:

$0.001/call settled via x402 on Base
Same response shape; richer factor list (OFAC + GoPlus + Etherscan + anomaly heuristics)
Plugins below handle x402 settlement for you

Caching + rate limits

1 r/s + burst 3 per IP. Cache on your side or proxy through your backend.
Treasury refreshes the SDN feed daily; PaladinFi refreshes ours approximately once per 24h.
Low-stakes UX gates: 1-6h client cache is the safe default.
High-stakes flows (transfers >$X, contract deploys, sensitive actions): re-screen per-action; don't rely on a long cache.
Audit-grade compliance: query Treasury XML directly.
Rate-limit response is HTTP 429. Treat as transient: retry with backoff, or surface to your backend proxy. The React hook above collapses 429 into the generic "error" verdict; production code should branch on r.status === 429 and retry rather than fail-close.

Scope of coverage

Scope is OFAC SDN cryptocurrency-tagged wallet addresses only (~93 entries as of 2026-05-27). Not the EU consolidated list, not UK OFSI, not UN sanctions, not token contracts, not entity names, not country-level sanctions. For broader coverage, layer additional providers.

This endpoint surfaces the signal. Your dApp decides policy.

Plugins + MCP

If you're using ElizaOS: npm i @paladinfi/eliza-plugin-trust
If you're using AgentKit: npm i @paladinfi/agentkit-actions
If your client speaks MCP (Claude Code, Cursor, etc.): claude mcp add --transport http --scope user paladin-swap https://swap.paladinfi.com/mcp (listing)
Full trust-check (paid, multi-source): paladinfi.com/trust-check/

Last Updated: 2026-05-27 · API version: 1.1 · Service version: 0.11.77