Pre-quote price sanity check: median across CoinGecko + DexScreener + GeckoTerminal with per-source quotes and spread in bps (broken >20%-off sources excluded from spread, kept visible). token = ticker (eth/btc/usdc/usdt/dai/aero…) or any ERC-20 address. Detects stale or divergent feeds before an agent quotes or trades. Chains: ethereum, base, arbitrum, optimism.