​
MetaMask

On node access details, click Add to MetaMask.

​
Hardhat

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

1

Install Hardhat and create a project.

2

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
3

Run npx hardhat run scripts/deploy.js --network chainstack and Hardhat will deploy using Chainstack.

See also Forking EVM-compatible mainnet with Hardhat.

​
Remix IDE

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

1

Get MetaMask and set it to interact through a Chainstack node. See Interacting through MetaMask.

2

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 Cronos nodes deployed with Chainstack.

1

Install web3.js.

2

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 Cronos nodes deployed with Chainstack.

1

Install web3.py.

2

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)

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)

See also node access details.

​
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)

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)

See also WebSocket connection to an EVM node.

​
web3.php

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

1

Install web3.php.

2

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

3

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 Cronos 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

See also the full code on GitHub.

​
ethers.js

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

1

Install ethers.js.

2

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);

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 — Cronos network ID:

    • Mainnet: 25
    • Testnet: 338

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 WSS endpoint endpoint protected either with the key or password

  • NETWORK_ID — Cronos network ID:

    • Mainnet: 25
    • Testnet: 338

​
Brownie

1

Install Brownie.

2

Use the brownie networks add command with the node endpoint:

brownie networks add Cronos 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, chainstack-mainnet.

  • NETWORK_NAME — any name that you want to identify the network by in the list of networks. For example, Mainnet (Chainstack).

  • YOUR_CHAINSTACK_ENDPOINT — your node HTTPS or WSS endpoint protected either with the key or password

  • NETWORK_ID — Cronos network ID:

    • Mainnet: 25
    • Testnet: 338

Example to run the deployment script:

brownie run deploy.py --network chainstack-mainnet

​
Foundry

1

Install Foundry.

2

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