Node Quickstart

Get started with CDP Node in minutes. This guide shows you how to get your RPC endpoint and make your first blockchain request—both in the browser playground and programmatically in your code.

Prerequisites

• A free CDP account

That’s it! No complex setup, no infrastructure to manage.

1. Try it in the playground

2. Get your RPC endpoint

To use Node in your application, you need an RPC endpoint URL. This is the web address where you send blockchain requests—think of it like an API endpoint, but specifically for blockchain operations.

1. Navigate to Node

   Go to the Node page in CDP Portal.

2. Select your network

   Choose your target network from the dropdown:

   • Base Mainnet - For production applications
   • Base Sepolia - For development and testing

   
3. Copy your endpoint URL

   Copy the displayed RPC endpoint URL. It will look like:

   https://api.developer.coinbase.com/rpc/v1/base/YOUR_CLIENT_API_KEY
   

   The Client API key is automatically included in the URL for authentication.

About Client API Keys

Your RPC endpoint URL includes a Client API key, which is designed for client-side use and is safe to include in frontend code. For more details, see Client API Key.

3. Make your first request

Now let’s make your first blockchain request programmatically. We’ll query the current block number on Base.

cURL

curl https://api.developer.coinbase.com/rpc/v1/base/YOUR_CLIENT_API_KEY \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "eth_blockNumber"
  }'

Response:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x12a4b2c"
}

JavaScript (fetch)

const rpcUrl = "https://api.developer.coinbase.com/rpc/v1/base/YOUR_CLIENT_API_KEY";

const response = await fetch(rpcUrl, {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    jsonrpc: "2.0",
    id: 1,
    method: "eth_blockNumber",
  }),
});

const data = await response.json();
console.log("Current block:", parseInt(data.result, 16));

Python

import requests
import json

rpc_url = "https://api.developer.coinbase.com/rpc/v1/base/YOUR_CLIENT_API_KEY"

payload = {
    "jsonrpc": "2.0",
    "id": 1,
    "method": "eth_blockNumber"
}

response = requests.post(rpc_url, json=payload)
result = response.json()

# Convert hex to decimal
block_number = int(result["result"], 16)
print(f"Current block: {block_number}")

Node.js

const https = require("https");

const rpcUrl = "https://api.developer.coinbase.com/rpc/v1/base/YOUR_CLIENT_API_KEY";

const payload = JSON.stringify({
  jsonrpc: "2.0",
  id: 1,
  method: "eth_blockNumber",
});

const options = {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
  },
};

const req = https.request(rpcUrl, options, (res) => {
  let data = "";
  res.on("data", (chunk) => (data += chunk));
  res.on("end", () => {
    const result = JSON.parse(data);
    console.log("Current block:", parseInt(result.result, 16));
  });
});

req.write(payload);
req.end();

Using Ethereum libraries? Node works with any Ethereum-compatible library like ethers.js, viem, web3.js, or web3.py. Just use your RPC endpoint URL as the provider.

What to read next

• Core EVM Methods: Explore all available JSON-RPC methods
• Paymaster Methods: Learn how to sponsor gas fees for your users
• Wallet History Methods: Query historical wallet data
• Rate Limits: Understand your usage limits and request increases
• CDP Discord: Join #node for support and to request rate limit increases