Entity attribution — what IS this address, not who owns it. Params: address (0x EVM address, required); chain (base default, or ethereum). Returns { address, chain, is_known, label, category }. category is one of sanctioned, mixer, exchange, bridge, dex_router, scam, drainer, phishing, flagged, token_contract, protocol, unknown. "sanctioned" is set only when the address is on the OFAC SDN list (the same source /api/risk uses); a non-OFAC blocklist hit is "flagged". Sourced from OFAC, ScamSniffer, MEW, eth-labels and curated Base/Tornado sets. Never guesses. Free.