Avalanche C-Chain

Endpoint	https://rpc.lab.au.ro/avax
Protocol	JSON-RPC 2.0 over HTTPS (POST)
chainId	43114 (0xa86a)
Batch	✓

The gateway path maps straight to the C-Chain EVM RPC (/ext/bc/C/rpc upstream) — you do not append AvalancheGo's extension paths yourself.

Supported methods

Same live-verified EVM surface as Ethereum. X-Chain / P-Chain APIs are not exposed. debug_*/trace_* unavailable.

Quick test

curl -X POST https://rpc.lab.au.ro/avax \
  -H "apikey: $YOUR_API_KEY" -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}'
# {"jsonrpc":"2.0","id":1,"result":"0xa86a"}

SDK integration

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

const client = createPublicClient({
  chain: avalanche,
  transport: http('https://rpc.lab.au.ro/avax', {
    fetchOptions: { headers: { apikey: process.env.YOUR_API_KEY } }
  })
})
console.log(await client.getChainId())   // 43114

ethers v6: same FetchRequest pattern as Ethereum.

Recipes

• Finality — Avalanche finalizes in ~1–2 s; a transaction visible via eth_getTransactionReceipt is final (no reorg waiting like on Ethereum).
• AVAX balance — standard eth_getBalance (18 decimals on C-Chain).

Limitations

• C-Chain only; for X-/P-Chain operations use a wallet/SDK that talks to those VMs directly.
• Pruned node — recent state only.