> ## Documentation Index
> Fetch the complete documentation index at: https://docs.moralis.com/llms.txt
> Use this file to discover all available pages before exploring further.

# JSON-RPC Overview

> Learn about JSON-RPC, the protocol used for blockchain communication

## What is JSON-RPC?

JSON-RPC is a lightweight, remote procedure call (RPC) protocol that uses JSON to encode messages. It enables applications to invoke methods on remote systems as if they were local.

## Key Characteristics

* **Protocol-Agnostic** - Works over HTTP, WebSocket, and other transports
* **Stateless** - Each request is independent
* **Lightweight** - JSON formatting minimizes overhead while remaining human-readable

## Request Structure

A JSON-RPC request contains:

| Field     | Description                         |
| --------- | ----------------------------------- |
| `jsonrpc` | Protocol version (always "2.0")     |
| `method`  | Name of the method to call          |
| `params`  | Method parameters (array or object) |
| `id`      | Unique request identifier           |

### Example Request

```json theme={null}
{
  "jsonrpc": "2.0",
  "method": "eth_getBalance",
  "params": ["0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045", "latest"],
  "id": 1
}
```

## Response Structure

| Field     | Description                   |
| --------- | ----------------------------- |
| `jsonrpc` | Protocol version              |
| `result`  | Method result (if successful) |
| `error`   | Error object (if failed)      |
| `id`      | Matching request identifier   |

### Example Response

```json theme={null}
{
  "jsonrpc": "2.0",
  "result": "0x1234567890abcdef",
  "id": 1
}
```

## Common Methods

| Method                     | Description                       |
| -------------------------- | --------------------------------- |
| `eth_blockNumber`          | Get the latest block number       |
| `eth_getBalance`           | Get account balance               |
| `eth_getTransactionByHash` | Get transaction details           |
| `eth_sendRawTransaction`   | Submit a signed transaction       |
| `eth_call`                 | Execute a read-only contract call |
| `eth_getLogs`              | Get event logs                    |

## Use Cases

* **Wallets** - Query balances and submit transactions
* **dApps** - Interact with smart contracts
* **Indexers** - Fetch and process blockchain data
* **Trading Bots** - Monitor state and execute trades