Ethereum

Endpoint	https://rpc.lab.au.ro/eth
Protocol	JSON-RPC 2.0 over HTTPS (POST)
chainId	1 (0x1)
Batch	✓ (correlated by id)

Supported methods

The full standard surface, live-verified: eth_blockNumber, eth_chainId, eth_gasPrice, eth_maxPriorityFeePerGas, eth_feeHistory, eth_getBalance, eth_getTransactionCount, eth_getCode, eth_getStorageAt, eth_getBlockByNumber, eth_getBlockByHash, eth_getTransactionByHash, eth_getTransactionReceipt, eth_call, eth_estimateGas, eth_getLogs, eth_sendRawTransaction, net_version, web3_clientVersion.

Restrictions:

• eth_getLogs / eth_getFilterLogs — 1 request/min per key (heavy-method guard, HTTP 429 + Retry-After beyond that).
• debug_* — not available (HTTP 403 at the gateway).
• trace_* — requires an archive node; not offered on the standard endpoint.

Quick test

curl -X POST https://rpc.lab.au.ro/eth \
  -H "apikey: $YOUR_API_KEY" -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}'
# {"jsonrpc":"2.0","id":1,"result":"0x18213bb"}

SDK integration

ethers v6

import { ethers } from 'ethers'

const req = new ethers.FetchRequest('https://rpc.lab.au.ro/eth')
req.setHeader('apikey', process.env.YOUR_API_KEY)
const provider = new ethers.JsonRpcProvider(req)

console.log(await provider.getBlockNumber())        // 25301941
console.log(await provider.getFeeData())            // gasPrice, maxFeePerGas…

viem

import { createPublicClient, http } from 'viem'
import { mainnet } from 'viem/chains'

const client = createPublicClient({
  chain: mainnet,
  transport: http('https://rpc.lab.au.ro/eth', {
    fetchOptions: { headers: { apikey: process.env.YOUR_API_KEY } }
  })
})

console.log(await client.getBlockNumber())          // 25301917n
console.log(await client.getGasPrice())             // 424657331n

URL-key style

# The key may ride a query parameter instead of a header — handy for tools
# that only accept a URL. Prefer the header in production (URLs get logged).
curl -X POST "https://rpc.lab.au.ro/eth?apikey=$YOUR_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}'

Recipes

Wait for new blocks (no WebSocket needed)

eth_blockNumber is cached for 2 s server-side, so polling every 3–4 s is both fresh and cheap (1 CU):

let last = 0n
setInterval(async () => {
  const n = await client.getBlockNumber()
  if (n > last) { last = n; console.log('new block', n) }
}, 4000)

Read an ERC-20 balance

import { erc20Abi } from 'viem'

const usdc = '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48'
const balance = await client.readContract({
  address: usdc, abi: erc20Abi,
  functionName: 'balanceOf', args: ['0x...your address...']
})

Send a transaction

Sign locally, broadcast the raw bytes — the platform never sees your key:

import { createWalletClient, http } from 'viem'
import { privateKeyToAccount } from 'viem/accounts'

const account = privateKeyToAccount(process.env.PRIVATE_KEY)
const wallet = createWalletClient({ account, chain: mainnet, transport })
const hash = await wallet.sendTransaction({ to: '0x...', value: 10n ** 15n })
// then poll client.getTransactionReceipt({ hash })

eth_sendRawTransaction costs 20 CU and is never cached.

Limitations

• No archive state: historical balance/storage queries older than the node's pruning horizon return errors; trace_*/debug_* are unavailable.
• eth_getLogs is rate-limited to 1/min — for indexing workloads, sweep small ranges and respect Retry-After.