RPC API Reference

Liberty Chain exposes a standard Ethereum JSON-RPC API. If you have worked with any EVM chain before, the same methods, request format, and client libraries all work here. This page covers the endpoint details, supported methods, and usage examples.

Endpoint

HTTPS	https://testnet-rpc.lcx.com
WebSocket	wss://testnet-rpc.lcx.com
Chain ID	76847801

No API Key Required

The public RPC endpoint does not require an API key. Rate limits apply to ensure fair usage across all developers.

Supported Methods

Liberty Chain supports the standard Ethereum JSON-RPC methods, plus OP Stack-specific methods for rollup status. The table below lists the most commonly used methods.

Standard Ethereum Methods

Method	Description
eth_blockNumber	Returns the latest block number
eth_getBalance	Returns the balance of an address in wei
eth_getTransactionCount	Returns the nonce for an address
eth_sendRawTransaction	Submits a signed transaction to the network
eth_call	Executes a read-only call against a contract
eth_estimateGas	Estimates the gas needed for a transaction
eth_getTransactionReceipt	Returns the receipt for a mined transaction
eth_getBlockByNumber	Returns block data by block number
eth_getBlockByHash	Returns block data by block hash
eth_getLogs	Returns logs matching a filter
eth_getCode	Returns the bytecode at an address
eth_gasPrice	Returns the current gas price in wei
eth_chainId	Returns the chain ID (76847801)
net_version	Returns the network ID

OP Stack-Specific Methods

Method	Description
optimism_syncStatus	Returns the current sync status of the node, including the latest L1 and L2 block references and their safety levels.
optimism_outputAtBlock	Returns the output root at a given L2 block number, used by the proposer and verifier for fault proofs.

Usage Examples

Get the Latest Block Number

curl — eth_blockNumber

bash

curl -X POST https://testnet-rpc.lcx.com \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_blockNumber",
    "params": [],
    "id": 1
  }'

Response

json

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x1a4b2"
}

Get Account Balance

curl — eth_getBalance

bash

curl -X POST https://testnet-rpc.lcx.com \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_getBalance",
    "params": ["0xYOUR_ADDRESS_HERE", "latest"],
    "id": 1
  }'

Estimate Gas

curl — eth_estimateGas

bash

curl -X POST https://testnet-rpc.lcx.com \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_estimateGas",
    "params": [{
      "from": "0xSENDER_ADDRESS",
      "to": "0xRECIPIENT_ADDRESS",
      "value": "0xde0b6b3a7640000"
    }],
    "id": 1
  }'

Send a Raw Transaction

curl — eth_sendRawTransaction

bash

curl -X POST https://testnet-rpc.lcx.com \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_sendRawTransaction",
    "params": ["0xSIGNED_TRANSACTION_DATA"],
    "id": 1
  }'

Using ethers.js

ethers.js example

javascript

import { ethers } from "ethers";

const provider = new ethers.JsonRpcProvider(
  "https://testnet-rpc.lcx.com"
);

// Get latest block number
const blockNumber = await provider.getBlockNumber();
console.log("Latest block:", blockNumber);

// Get balance
const balance = await provider.getBalance("0xYOUR_ADDRESS");
console.log("Balance:", ethers.formatEther(balance), "ETH");

// Get gas price
const feeData = await provider.getFeeData();
console.log("Gas price:", ethers.formatUnits(feeData.gasPrice, "gwei"), "gwei");

WebSocket Subscriptions

For real-time data such as new blocks, pending transactions, or event logs, use the WebSocket endpoint. WebSocket connections support the eth_subscribe method for push-based notifications.

WebSocket subscription

javascript

import { ethers } from "ethers";

const wsProvider = new ethers.WebSocketProvider(
  "wss://testnet-rpc.lcx.com"
);

// Subscribe to new blocks
wsProvider.on("block", (blockNumber) => {
  console.log("New block:", blockNumber);
});

// Subscribe to contract events
const contract = new ethers.Contract(contractAddress, abi, wsProvider);
contract.on("Transfer", (from, to, value) => {
  console.log(`Transfer: ${from} -> ${to}: ${value}`);
});

Rate Limits

The public RPC endpoint enforces rate limits to ensure fair access for all users. Current limits are:

Limit	Value
Requests per second (per IP)	25
Batch request size	20 calls per batch
WebSocket connections (per IP)	5
eth_getLogs block range	10,000 blocks

Rate Limit Exceeded

If you receive HTTP 429 responses, you are exceeding the rate limit. Implement exponential backoff in your application, or consider batching multiple calls into a single request to reduce your request count.

For production applications that require higher throughput, contact the Liberty Chain team to discuss dedicated RPC access.