How JSON-RPC Works

JSON-RPC operates in a straightforward request-response model, allowing developers to call methods on remote servers with minimal configuration. The client sends a JSON-encoded request to a server, which processes the request and returns a JSON-encoded response.

Components of JSON-RPC

1. Request

   • The client sends a request containing:
     • jsonrpc: The protocol version (e.g., "2.0").
     • method: The name of the method being invoked.
     • params: An array or object containing the method's parameters.
     • id: A unique identifier to match the response.

2. Response

   • The server responds with:
     • result: The result of the method invocation.
     • id: The same id from the request to match the response.
     • error: Optional, only present if the request fails.

Example of a JSON-RPC Flow

1. Client Request:

   {
     "jsonrpc": "2.0",
     "method": "eth_getBlockByNumber",
     "params": ["0x10d4f", true],
     "id": 1
   }

2. Server Response:

   {
   "jsonrpc": "2.0",
   "result": {
    "number": "0x10d4f",
    "hash": "0xabc123...",
    "transactions": [...]
   },
   "id": 1
   }

This simplicity makes JSON-RPC an ideal choice for systems where performance, minimalism, and ease of use are priorities, such as querying blockchain data.

Batch Requests

JSON-RPC supports sending multiple requests in a single batch, improving performance and reducing latency.

Example:

[
  {
    "jsonrpc": "2.0",
    "method": "eth_getBlockByNumber",
    "params": ["0x10d4f", true],
    "id": 1
  },
  {
    "jsonrpc": "2.0",
    "method": "eth_getBalance",
    "params": ["0x123456..."],
    "id": 2
  }
]

This enables you to execute multiple calls in parallel, reducing overhead and network latency.