🏅Hacker's Getting Started Resources

Quick-start resource if you are hacking and need to integrate with Cronos.

Overview of Cronos chain

Cronos (cronos.org) is the leading Ethereum-compatible layer 1 blockchain network built on the Cosmos SDK, supported by Crypto.com, Crypto.org and more than 500 app developers and partners. Today, the #CROfam ecosystem represents an addressable user base of more than 80 million people worldwide. Our mission is to make it easy and safe for the next billion crypto users to adopt Web3, with a focus on DeFi and GameFi.

Getting Started

How to stand out and win in a Web3 hackathon 🥇

Check out our blog post.

Hack with Cronos 🥚

Developing Dapps on Cronos is as easy as developing them on any of the major EVM-compatible chains: write and test solidity with Hardhat, deploy your contract, connect your frontend or your backend with ethers.js, and connect your wallet with MetaMask or Crypto.com Onchain Wallet.

The native cryptocurrency of Cronos mainnet is CRO, while the testnet uses TCRO.

Cronos overview & key links for developers

Cronos docs: https://docs.cronos.org
Cronos Play (for game developers): https://cronos.org/play
Why build on Cronos
Cronos overview by Eat The Blocks: https://www.youtube.com/watch?v=NqeeKEJiPZU

MetaMask end-user configuration

The cronos.org website has a little orange button at the top of the page, that you can click to add Cronos mainnet to your MetaMask wallet.
For more details, see Metamask configuration

JSON-RPC endpoint configuration

For most use cases you can use the free endpoints that are provided by Cronos Labs. Most developers use a configuration file that looks like this:

For Hardhat:

{
"cronos_mainnet": {
      "chainId": 25,
      "url": "https://evm.cronos.org/",
      "gasPrice": 5000000000000,
      "blockExplorer": "https://explorer.cronos.org/",
      "blockExplorerPrefix": "https://explorer.cronos.org/tx/"
    },
"cronos_testnet": {
      "chainId": 338,
      "url": "https://evm-t3.cronos.org/",
      "gasPrice": 5000000000000,
      "blockExplorer": "https://explorer.cronos.org/testnet/",
      "blockExplorerPrefix": "https://explorer.cronos.org/testnet/tx/"
    },
}

or, using EIP1559 in a Node.js backend:

{
"cronos_mainnet": {
      "id": 25,
      "url": "https://evm.cronos.org/",
      "maxPriorityFeePerGas": 5000000000,
      "maxFeePerGas": 6000000000000,
      "blockExplorer": "https://explorer.cronos.org/",
      "blockExplorerPrefix": "https://explorer.cronos.org/tx/"
    },
"cronos_testnet": {
      "id": 338,
      "url": "https://evm-t3.cronos.org/",
      "maxPriorityFeePerGas": 5000000000,
      "maxFeePerGas": 6000000000000,
      "blockExplorer": "https://explorer.cronos.org/",
      "blockExplorerPrefix": "https://explorer.cronos.org/tx/"
    },
}