Quickstart

Create a free Bootnode account at dashboard.bootnode.dev. After signing up, navigate to Settings → API Keys and create a new key. Copy it -- you will need it for every request.

bn_live_a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6

Use curl to call eth_blockNumber on Ethereum mainnet. This returns the latest block number in hexadecimal.

curl -X POST https://api.bootnode.dev/v1/rpc/ethereum/mainnet \
  -H "Content-Type: application/json" \
  -H "X-API-Key: YOUR_API_KEY" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "eth_blockNumber",
    "params": []
  }'

Response:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x13a5e7f"
}

For TypeScript and JavaScript projects, install the official SDK:

npm install @bootnode/sdk

Or with other package managers:

# yarn
yarn add @bootnode/sdk

# pnpm
pnpm add @bootnode/sdk

# bun
bun add @bootnode/sdk

Here is a complete TypeScript example that fetches the latest block number, gets an ETH balance, and retrieves ERC-20 token balances for a wallet.

import { Bootnode } from "@bootnode/sdk";

const client = new Bootnode({
  apiKey: process.env.BOOTNODE_API_KEY!,
});

// 1. Get the latest block number via JSON-RPC
async function getBlockNumber(): Promise<string> {
  const response = await client.rpc("ethereum", "mainnet", {
    jsonrpc: "2.0",
    id: 1,
    method: "eth_blockNumber",
    params: [],
  });
  return response.result; // e.g. "0x13a5e7f"
}

// 2. Get ETH balance using JSON-RPC
async function getBalance(address: string): Promise<string> {
  const response = await client.rpc("ethereum", "mainnet", {
    jsonrpc: "2.0",
    id: 1,
    method: "eth_getBalance",
    params: [address, "latest"],
  });
  return response.result; // wei in hex, e.g. "0x6f05b59d3b20000"
}

// 3. Get ERC-20 token balances via Token API
async function getTokenBalances(address: string) {
  const balances = await client.tokens.getBalances("ethereum", address);
  return balances;
  // Returns: [{ contract: "0xa0b8...", symbol: "USDC", balance: "1500.00", ... }]
}

async function main() {
  const blockNumber = await getBlockNumber();
  console.log("Latest block:", parseInt(blockNumber, 16));

  const address = "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045";
  const balance = await getBalance(address);
  console.log("ETH balance (wei):", BigInt(balance).toString());

  const tokens = await getTokenBalances(address);
  console.log("Token balances:", tokens);
}

main();

You do not need the SDK. Every Bootnode API is a standard REST or JSON-RPC endpoint. Here is a plain fetch example:

const API_KEY = process.env.BOOTNODE_API_KEY;
const BASE_URL = "https://api.bootnode.dev/v1";

// JSON-RPC call
async function ethBlockNumber(): Promise<number> {
  const res = await fetch(`${BASE_URL}/rpc/ethereum/mainnet`, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      "X-API-Key": API_KEY!,
    },
    body: JSON.stringify({
      jsonrpc: "2.0",
      id: 1,
      method: "eth_blockNumber",
      params: [],
    }),
  });

  if (!res.ok) {
    throw new Error(`HTTP ${res.status}: ${await res.text()}`);
  }

  const data = await res.json();
  return parseInt(data.result, 16);
}

// REST API call - get token balances
async function getTokenBalances(address: string) {
  const res = await fetch(
    `${BASE_URL}/tokens/ethereum/balances/${address}`,
    {
      headers: { "X-API-Key": API_KEY! },
    }
  );

  if (!res.ok) {
    throw new Error(`HTTP ${res.status}: ${await res.text()}`);
  }

  return res.json();
}

// Usage
const blockNum = await ethBlockNumber();
console.log("Block:", blockNum);

const tokens = await getTokenBalances(
  "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"
);
console.log("Tokens:", tokens);

Next Steps