Optimism

MetaMask

On the node access page, click Add to MetaMask.

Truffle

Configure Truffle Suite to deploy contracts to your Optimism nodes.

Install Truffle Suite, HD Wallet-enabled Web3 provider, and create a project.

Create a new environment in truffle-config.js, add your mnemonic phrase generated by a wallet and the Optimism endpoint instead of YOUR_CHAINSTACK_ENDPOINT:

const HDWalletProvider = require("@truffle/hdwallet-provider");
const mnemonic = 'pattern enroll upgrade ...';
...
module.exports = {
 networks: {
    chainstack: {
        provider: () => new HDWalletProvider(mnemonic, "YOUR_CHAINSTACK_ENDPOINT"),
        network_id: "*"
    },
   }
  }
};

Hardhat

Configure Hardhat to deploy contracts and interact through your Optimism nodes.

Install Hardhat and create a project.
Create a new environment in hardhat.config.js:
```
require("@nomiclabs/hardhat-waffle");
...
module.exports = {
  solidity: "0.7.3",
  networks: {
    chainstack: {
        url: "YOUR_CHAINSTACK_ENDPOINT",
        accounts: ["YOUR_PRIVATE_KEY"]
    },
  }
};
```
where
- YOUR_CHAINSTACK_ENDPOINT — your node HTTPS or WSS endpoint protected either with the key or password. See node access details.
- YOUR_PRIVATE_KEY — the private key of the account that you use to deploy the contract
Run npx hardhat run scripts/deploy.js --network chainstack and Hardhat will deploy using Chainstack.

Remix IDE

To make Remix IDE interact with the network through a Chainstack node:

Get MetaMask and set it to interact through a Chainstack node. See Interacting through MetaMask.
In Remix IDE, navigate to the Deploy tab. Select Injected Provider - MetaMask in Environment.

This will engage MetaMask and make Remix IDE interact with the network through a Chainstack node.

web3.js

Build DApps using web3.js and Polygon nodes deployed with Chainstack.

Install web3.js.
Connect over HTTP or WebSocket.

HTTP

Use the HttpProvider object to connect to your node HTTPS endpoint and get the latest block number:

const Web3 = require('web3');

const web3 = new Web3(new Web3.providers.HttpProvider('YOUR_CHAINSTACK_ENDPOINT'));

web3.eth.getBlockNumber().then(console.log);

where YOUR_CHAINSTACK_ENDPOINT is your node HTTPS endpoint protected either with the key or password.

WebSocket

Use the WebsocketProvider object to connect to your node WSS endpoint and get the latest block number:

const Web3 = require('web3');

const web3 = new Web3(new Web3.providers.WebsocketProvider('YOUR_CHAINSTACK_ENDPOINT'));

web3.eth.getBlockNumber().then(console.log);

where YOUR_CHAINSTACK_ENDPOINT is your node WSS endpoint protected either with the key or password.

web3.py

Build DApps using web3.py and Optimism nodes deployed with Chainstack.

Install web3.py.
Connect over HTTP or WebSocket. See also EVM node connection: HTTP vs WebSocket.

HTTP

Use the HTTPProvider to connect to your node endpoint and get the latest block number.

from web3 import Web3

web3 = Web3(Web3.HTTPProvider('YOUR_CHAINSTACK_ENDPOINT'))
print(web3.eth.blockNumber)

from web3 import Web3

web3 = Web3(Web3.HTTPProvider('https://%s:%s@%s'% ("USERNAME", "PASSWORD", "HOSTNAME")))
print(web3.eth.blockNumber)

where

YOUR_CHAINSTACK_ENDPOINT — your node HTTPS endpoint protected either with the key or password
HOSTNAME — your node HTTPS endpoint hostname
USERNAME — your node access username (for password-protected endpoints)
PASSWORD — your node access password (for password-protected endpoints)

WebSocket

Use the WebsocketProvider object to connect to your node WSS endpoint and get the latest block number.

from web3 import Web3

web3 = Web3(Web3.WebsocketProvider('YOUR_CHAINSTACK_ENDPOINT'))
print(web3.eth.blockNumber)

from web3 import Web3

web3 = Web3(Web3.WebsocketProvider('wss://%s:%s@%s'% ("USERNAME", "PASSWORD", "HOSTNAME")))
print(web3.eth.blockNumber)

where

YOUR_CHAINSTACK_ENDPOINT — your node WSS endpoint protected either with the key or password
HOSTNAME — your node WSS endpoint hostname
USERNAME — your node access username (for password-protected endpoints)
PASSWORD — your node access password (for password-protected endpoints)

web3.php

Build DApps using web3.php and Optimism nodes deployed with Chainstack.

Install web3.php.

Connect over HTTP:

<?php

require_once "vendor/autoload.php";

use Web3\Web3;
use Web3\Providers\HttpProvider;
use Web3\RequestManagers\HttpRequestManager;

$web3 = new Web3(new HttpProvider(new HttpRequestManager("YOUR_CHAINSTACK_ENDPOINT", 5)));
?>

where YOUR_CHAINSTACK_ENDPOINT is your node HTTPS endpoint protected either with the key or password

Use JSON-RPC methods to interact with the node.

Example to get the latest block number:

<?php

require_once "vendor/autoload.php";

use Web3\Web3;
use Web3\Providers\HttpProvider;
use Web3\RequestManagers\HttpRequestManager;

$web3 = new Web3(new HttpProvider(new HttpRequestManager("YOUR_CHAINSTACK_ENDPOINT", 5)));

$eth = $web3->eth;

$eth->blockNumber(function ($err, $data) {
     print "$data \n";
});
?>

web3j

Build DApps using web3j and Optimism nodes deployed with Chainstack.

Use the HttpService object to connect to your node endpoint.

Example to get the latest block number:

package getLatestBlock;

import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.web3j.protocol.Web3j;
import org.web3j.protocol.core.DefaultBlockParameterName;
import org.web3j.protocol.core.methods.response.EthBlock;
import org.web3j.protocol.exceptions.ClientConnectionException;
import org.web3j.protocol.http.HttpService;

import okhttp3.Authenticator;
import okhttp3.Credentials;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import okhttp3.Route;

public final class App {

  private static final String USERNAME = "USERNAME";
  private static final String PASSWORD = "PASSWORD";
  private static final String ENDPOINT = "ENDPOINT";

  public static void main(String[] args) {
    try {

      OkHttpClient.Builder clientBuilder = new OkHttpClient.Builder();
      clientBuilder.authenticator(new Authenticator() {
          @Override public Request authenticate(Route route, Response response) throws IOException {
              String credential = Credentials.basic(USERNAME, PASSWORD);
              return response.request().newBuilder().header("Authorization", credential).build();
          }
      });

      HttpService service = new HttpService(RPC_ENDPOINT, clientBuilder.build(), false);
      Web3j web3 = Web3j.build(service);


      EthBlock.Block latestBlock = web3.ethGetBlockByNumber(DefaultBlockParameterName.LATEST, false).send().getBlock();


      System.out.println("Latest Block: #" + latestBlock.getNumber());

    } catch (IOException | ClientConnectionException ex) {

      Logger.getLogger(App.class.getName()).log(Level.SEVERE, null, ex);
    }
  }

}

where

ENDPOINT — your node HTTPS endpoint
USERNAME — your node access username
PASSWORD — your node access password

ethers.js

Build DApps using ethers.js and Optimism nodes deployed with Chainstack.

Install ethers.js.
Connect over HTTP or WebSocket. See also EVM node connection: HTTP vs WebSocket.

HTTP

Use the JsonRpcProvider object to connect to your node endpoint and get the latest block number:

const { ethers } = require("ethers");

var urlInfo = {
    url: 'YOUR_CHAINSTACK_ENDPOINT'
};
var provider = new ethers.providers.JsonRpcProvider(urlInfo, NETWORK_ID);

provider.getBlockNumber().then(console.log);

const { ethers } = require("ethers");

var urlInfo = {
    url: 'YOUR_CHAINSTACK_ENDPOINT',
    user: 'USERNAME',
    password: 'PASSWORD'
};
var provider = new ethers.providers.JsonRpcProvider(urlInfo, NETWORK_ID);

provider.getBlockNumber().then(console.log);

where

YOUR_CHAINSTACK_ENDPOINT — your node HTTPS endpoint protected either with the key or password
USERNAME — your node access username (for password-protected endpoints)
PASSWORD — your node access password (for password-protected endpoints)
NETWORK_ID — Optimism network ID:
- Mainnet: 10
- Testnet: 420

See node access details.

WebSocket

Use the WebSocketProvider object to connect to your node WSS endpoint and get the latest block number:

const { ethers } = require("ethers");

const provider = new ethers.providers.WebSocketProvider('YOUR_CHAINSTACK_ENDPOINT', NETWORK_ID);

provider.getBlockNumber().then(console.log);

where

YOUR_CHAINSTACK_ENDPOINT — your node HTTPS endpoint protected either with the key or password
USERNAME — your node access username (for password-protected endpoints)
PASSWORD — your node access password (for password-protected endpoints)
NETWORK_ID — Optimism network ID:
- Mainnet: 10
- Testnet: 420

See node access details.

Brownie

Install Brownie.
Use the brownie networks add command with the node endpoint:

brownie networks add Optimism ID name="NETWORK_NAME" host= YOUR_CHAINSTACK_ENDPOINT chainid=NETWORK_ID

where

ID — any name that you will use as the network tag to run a deployment. For example, optimism-testnet.
NETWORK_NAME — any name that you want to identify the network by in the list of networks. For example, Testnet (Chainstack).
YOUR_CHAINSTACK_ENDPOINT — your node HTTPS or WSS endpoint
NETWORK_ID — Optimism network ID:
- Mainnet: 10
- Testnet: 420

Example to run the deployment script:

brownie run deploy.py --network chainstack-testnet

Foundry

Install Foundry.
Use --rpc-url to run the operation through your Chainstack node.

Forge

Use forge to develop, test, and deploy your smart contracts.

To deploy a contract:

forge create CONTRACT_NAME --contracts CONTRACT_PATH --private-key YOUR_PRIVATE_KEY --rpc-url YOUR_CHAINSTACK_ENDPOINT

where

CONTRACT_NAME — name of the contract in the Solidity source code
CONTRACT_PATH — path to your smart contract
YOUR_PRIVATE_KEY — the private key to your funded account that you will use to deploy the contract
YOUR_CHAINSTACK_ENDPOINT — your node HTTPS endpoint protected either with the key or password

Cast

Use cast to interact with the network and the deployed contracts.

To get the latest block number:

cast block-number --rpc-url YOUR_CHAINSTACK_ENDPOINT

where YOUR_CHAINSTACK_ENDPOINT is your node HTTPS endpoint protected either with the key or password

GraphQL

You can use GraphQL on a dedicated node on the Growth, Business, and Enterprise subscription plans.

UI

You can query data using the graphical interface.

On Chainstack, navigate to your dedicated Ethereum node. See node access details.
Hover over GraphQL IDE URL and click Open.
In the graphical interface that opens, run a GraphQL query.

Example to get the latest block number:

{ block { number } }

Node.js

You can build a web app to query data using node.js and axios:

const axios = require('axios');
const main = async () => {
  try {
    const result = await axios.post(
      'YOUR_CHAINSTACK_ENDPOINT',
      {
        query: `
          { block { number } }
        `
      }
    );
    console.log(result.data);
  } catch(error) {
    console.error(error);
  }
}
main();

where

YOUR_CHAINSTACK_ENDPOINT — your node GraphQL endpoint protected either with the key or password. See node access details.
query — your GraphQL query. In this case, to get the latest block number.