Current gas price and EIP-1559 fee suggestions (base fee, priority tip, suggested max fee) on Ethereum, Base, Arbitrum,

Current gas price and EIP-1559 fee suggestions (base fee, priority tip, suggested max fee) on Ethereum, Base, Arbitrum, Optimism, Polygon, or BNB Chain, in gwei. Public JSON-RPC, no API keys. POST a JSON body like: {"chain":"ethereum"}