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Fuse is an EVM-compatible blockchain with 5-second block times and ~10 GWei gas. This guide covers the network details you need, how to deploy a Solidity contract using Hardhat, and how to connect to the FuseBox SDK once your contract is live.

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Network details

Fuse MainnetFuse Testnet (Sparknet)
Chain ID122123
RPChttps://rpc.fuse.iohttps://rpc.fusespark.io
SymbolFUSEFUSE
Explorerhttps://explorer.fuse.iohttps://explorer.fusespark.io
WebSocketwss://explorer-node.fuse.io/wswss://explorernode.fusespark.io/ws
Healthhttps://health.fuse.iohttps://health.fusespark.io
Block size20,000,00020,000,000
Block speed5 seconds5 seconds
Gas price10 GWei10 GWei
FaucetStakelyChainDrop, Stakely

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Core network contracts

The following contracts govern consensus, block rewards, and on-chain governance on Fuse Mainnet.
ContractAddress
Core Consensus0x3014ca10b91cb3D0AD85fEf7A3Cb95BCAc9c0f79
BlockReward0x63D4efeD2e3dA070247bea3073BCaB896dFF6C9B
Voting0x4c889f137232E827c00710752E86840805A70484

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Deploy a smart contract with Hardhat

Fuse is EVM-compatible, so any Solidity contract compiles and deploys without modification. The steps below use Hardhat’s Ignition deployment system to deploy an ERC-20 token to Fuse.
1

Create and initialise the project

Open a terminal and scaffold a new Hardhat project:
mkdir hardhat-fuse-guide && cd hardhat-fuse-guide
npm init -y
npx hardhat init
When prompted, accept the sample project defaults and install dependencies including hardhat and @nomicfoundation/hardhat-toolbox.
npm install --save-dev hardhat
npm install --save-dev @nomicfoundation/hardhat-toolbox
2

Write the contract

Inside the contracts/ folder, delete the default Lock.sol and create Token.sol with the following content:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@openzeppelin/contracts@4.0.0/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts@4.0.0/token/ERC20/extensions/ERC20Burnable.sol";
import "@openzeppelin/contracts@4.0.0/access/Ownable.sol";

contract MyToken is ERC20, ERC20Burnable, Ownable {
    constructor(address initialOwner)
        ERC20("MyToken", "MTK")
        Ownable()
    {}

    function mint(address to, uint256 amount) public onlyOwner {
        _mint(to, amount);
    }
}
3

Compile

npx hardhat compile
A successful compile returns:
Compiling...
Compiled 1 contract successfully
4

Create the Ignition deployment module

Create ignition/modules/deploy.js and paste the following:
const { buildModule } = require("@nomicfoundation/hardhat-ignition/modules");

const Token = buildModule("Token", (m) => {
  const contract = m.contract("Token");
  return { contract };
});

module.exports = Token;
5

Configure Fuse networks in Hardhat

Open hardhat.config.js and add the networks block:
module.exports = {
  // ...
  networks: {
    fuse: {
      url: "https://rpc.fuse.io/",
      accounts: [`0xPRIVATE_KEY`], // deployer private key
    },
    spark: {
      url: "https://rpc.fusespark.io/",
      accounts: [`0xPRIVATE_KEY`], // deployer private key
    },
  },
  // ...
};
Never commit private keys to source control. Use environment variables or a secrets manager instead. The EOA that owns the key must hold FUSE tokens to cover the deployment gas fee.
6

Deploy to Fuse

Deploy to Fuse Mainnet:
npx hardhat ignition deploy ./ignition/modules/deploy.js --network fuse
Or to Sparknet testnet:
npx hardhat ignition deploy ./ignition/modules/deploy.js --network spark
After deployment, paste the contract address into the Mainnet Explorer or Testnet Explorer to verify the transaction.

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Connect to FuseBox SDK after deployment

FuseBox is the recommended way to connect your deployed contract to a frontend. It provides ERC-4337 smart accounts, a Bundler, and a Paymaster for gasless transactions — no direct RPC calls required. Install the SDK and initialise it with your API key from console.fuse.io: 
npm install @fuseio/fusebox-web-sdk ethers

import { FuseSDK } from "@fuseio/fusebox-web-sdk";
import { ethers } from "ethers";

const apiKey = "YOUR_FUSEBOX_API_KEY";
const credentials = new ethers.Wallet(`0xPRIVATE_KEY`);

const fuseSDK = await FuseSDK.init(apiKey, credentials, {
  withPaymaster: true,
});

console.log(
  `Smart account address: https://explorer.fuse.io/address/${fuseSDK.wallet.getSender()}`
);
Setting withPaymaster: true sponsors gas fees for your users. Your Operator account’s Paymaster is pre-funded with 1 FUSE when you create it on the Console.
With the SDK initialised, you can call fuseSDK.transferToken(tokenAddress, recipient, amount) to move tokens, query balances, and carry out other on-chain operations without writing low-level transaction code. See the FuseBox SDK overview for the full API surface.

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