JSON-RPC
Quick Answer
JSON-RPC is the protocol used to communicate with blockchain nodes, allowing payment backends to monitor transactions, verify confirmations, and submit settlements.
Full Definition
JSON-RPC is a remote procedure call protocol encoded in JSON, used to communicate with blockchain nodes. It allows applications to send transactions, query balances, read smart contract state, and subscribe to events. Most Ethereum-compatible blockchains expose a JSON-RPC interface. Payment backends use JSON-RPC to monitor incoming transactions, verify confirmations, and submit settlement transactions programmatically.