Remote Procedure Call (RPC)

Under the hood, blockchain RPC almost always means JSON-RPC: a lightweight, stateless message format that wraps a method name and its parameters in JSON, sends them to a node, and gets a result back in the same format. It works over HTTP, WebSocket, or a local IPC socket, which is why the same standard covers a simple balance check and a live subscription to new blocks.

Ethereum and every EVM-compatible chain, including Polygon, Arbitrum, and Base, speak this dialect through standardized calls such as eth_getBalance, eth_call, and eth_sendRawTransaction. A wallet like MetaMask is essentially an RPC client: pick a network, and it just points at a different endpoint URL behind the scenes.

Running a full node to serve your own RPC requests demands hundreds of gigabytes of storage, constant uptime, and ongoing maintenance, so most developers and wallets instead rely on managed providers such as Infura and Alchemy, or free public endpoints for light use. Public endpoints are shared and rate-limited with no uptime guarantee, while paid, dedicated endpoints add service-level agreements, higher throughput, and historical archive data for production apps.

Because a small number of providers now handle a large share of Ethereum traffic, RPC access has become a known centralization concern: if a major provider goes down, wallets and dApps built on it can stall even though the blockchain itself keeps producing blocks. Decentralized RPC networks that route requests across many independent node operators have emerged specifically to reduce that single point of failure.