OFAC compliance for Web3 developers: Complete guide
Web3 developers should screen counterparties in both smart-contract and agent payment paths before value moves.
TL;DR
TL;DR: Web3 developers can add OFAC screening to any payment path with a single API call or an MCP server, screening counterparties in smart contracts, wallets, and agent flows before value moves.
Where Web3 payments happen
Web3 value moves through wallets, smart contracts, and increasingly through AI agents that pay on a user's behalf. Each of these is a point where a sanctioned counterparty could enter the flow. Because OFAC liability is strict and penalties start at $356,000 per violation, the developer who builds the path is well placed to build the control into it.
Screening in code
Screening is a single HTTP call that returns ALLOW or BLOCK in under 100 ms, checking names, wallets, and jurisdictions against live data (19,218 SDN names, 947 listed wallets, 16 jurisdictions, synced hourly). For agent-style integrations, the MCP server installs with pip install sanctions-mcp, so screening can run inside an agent's tool loop.
Integrations
- Agent frameworks: LangChain, CrewAI, Eliza, OpenAI Agents SDK.
- Payment rails: x402, Base/USDC, Coinbase AgentKit, AP2, ACP.
- Editors: Claude Code, Cursor, Windsurf.