Next transaction nonce for any Ethereum wallet via eth_getTransactionCount - how many txs it has sent
GET https://api.onesource.io/api/chain/nonce/:addressListed in 3 directories: bazaar, x402-list, x402-new. First seen 5 Sept 2026.
Call this service
The endpoint answers an unpaid request with an HTTP 402 and a payment challenge. @x402/fetch signs it, pays in USDC, and retries — you get the result back in one call.
import { wrapFetchWithPayment } from "@x402/fetch";
import { privateKeyToAccount } from "viem/accounts";
const account = privateKeyToAccount(process.env.PRIVATE_KEY);
const pay = wrapFetchWithPayment(fetch, account);
const res = await pay("https://api.onesource.io/api/chain/nonce/:address", {
method: "GET",
});
console.log(await res.json());More from api.onesource.io
Latest Ethereum block height - current chain tip via eth_blockNumber
ERC20 token balance for any Ethereum wallet - USDC, USDT, DAI, or any token - via balanceOf (eth_call) on OneSource live Ethereum RPC
ENS resolve - turn a .eth name into an address, or an address into its primary .eth name, via eth_call on OneSource live Ethereum RPC
Live wallet balance - native ETH plus up to 20 caller-supplied ERC20 tokens in one bounded RPC batch
Full Ethereum transaction details by hash via eth_getTransactionByHash - from, to, value, calldata, block
Fetch an Ethereum block header and transaction hashes by number, tag, or hex via eth_getBlockByNumber
Uptime and compliance: x402-list.com (CC BY 4.0). Safety scores: x402.direct. Call and payer counts: x402.new. AMNT indexes this endpoint and does not host, operate or vouch for it.