Onchain Pay Open Api

This is Binance's fiat-to-crypto onramp API with automatic RSA SHA256 request signing built in. You can let users buy crypto with credit cards, Google Pay, or P2P and send it directly to an external wallet address without manual withdrawals. The interesting bit is the ON_CHAIN_PROXY_MODE that lets you buy and execute a smart contract call in one flow, so you could theoretically go from fiat to staked-in-DeFi without touching a CEX interface. The skill handles all the signing complexity through a bash script, though you'll need your own Binance merchant credentials and PEM key. Eight endpoints cover everything from payment method discovery to order tracking across multiple chains.