Environment Setup

Intro

In this step-by-step guide we'll walk through setting up a Hardhat development environment you can use to build the examples in the Guides section, or to start your own Algebra Integral integration.

You have two options: Quick Start — clone the boilerplate and jump straight to writing contracts, or Start from Scratch — build everything from the ground up.

Quick Start

The Algebra boilerplate repo provides a Hardhat environment with the required Algebra packages already installed. Clone it and install the dependencies:

git clone https://github.com/cryptoalgebra/boilerplate
cd boilerplate
npm install

Then go to the Local Node with a Polygon Fork section below to complete setup and start building.

Start from Scratch

Prerequisites

Node.js v22 or later and NPM are required. If you haven't installed them yet:

Install Node.js and NPM

Once installed, create a new directory and initialize a project:

mkdir my-algebra-project
cd my-algebra-project
npm init -y
npm pkg set type=module

Install Hardhat

Hardhat is the Ethereum development toolset used for compiling, testing, and deploying contracts:

npm add --save-dev hardhat

Initialize a Hardhat project:

npx hardhat --init

When prompted, choose the JavaScript project template and accept the defaults.

This creates the standard folder structure: ./contracts for Solidity contracts, ./test for tests, and ./scripts for deployment scripts.

Install Algebra Packages

Add the Algebra Integral contracts as dependencies:

npm add @cryptoalgebra/integral-periphery @cryptoalgebra/integral-core

Install Hardhat Toolbox

Install the recommended Hardhat 3 bundle for Ethers.js and Mocha:

npm add --save-dev @nomicfoundation/hardhat-toolbox-mocha-ethers

Update your hardhat.config.js to use the plugin:

import { defineConfig } from "hardhat/config";
import hardhatToolboxMochaEthers from "@nomicfoundation/hardhat-toolbox-mocha-ethers";

export default defineConfig({
  plugins: [hardhatToolboxMochaEthers],
  solidity: {
    version: "0.8.20",
  },
});

Verify the Setup

To make sure the environment is set up correctly, try compiling a basic swap contract. Create ./contracts/Swap.sol and paste in the following:

// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity =0.8.20;

import '@cryptoalgebra/integral-periphery/contracts/interfaces/ISwapRouter.sol';
import '@cryptoalgebra/integral-periphery/contracts/libraries/TransferHelper.sol';

contract SimpleSwap {
    ISwapRouter public immutable swapRouter;
    address public constant DAI = 0x8f3Cf7ad23Cd3CaDbD9735AFf958023239c6A063;
    address public constant WMATIC = 0x0d500B1d8E8eF31E21C99d1Db9A6444d3ADf1270;

    constructor(ISwapRouter _swapRouter) {
        swapRouter = _swapRouter;
    }

    function swapMATICForDAI(uint256 amountIn) external returns (uint256 amountOut) {
        TransferHelper.safeTransferFrom(WMATIC, msg.sender, address(this), amountIn);
        TransferHelper.safeApprove(WMATIC, address(swapRouter), amountIn);

        ISwapRouter.ExactInputSingleParams memory params =
            ISwapRouter.ExactInputSingleParams({
                tokenIn: WMATIC,
                tokenOut: DAI,
                deployer: address(0),
                recipient: msg.sender,
                deadline: block.timestamp,
                amountIn: amountIn,
                amountOutMinimum: 0,
                sqrtPriceLimitX96: 0
            });
        amountOut = swapRouter.exactInputSingle(params);
    }
}

Build it:

npx hardhat build

If successful you'll see:

Compilation finished successfully

Local Node with a Polygon Fork

Testing against live on-chain liquidity is critical but expensive. Hardhat lets you run a local Polygon fork for free.

As a prerequisite, you'll need an RPC that supports forking. Alchemy includes this on its free tier.

Start the local fork node:

npx hardhat node --fork https://polygon-mainnet.g.alchemy.com/v2/{YOUR_API_KEY}

With the node running, use the --network localhost flag to run tests against it:

npx hardhat test --network localhost

Next Steps

With your environment set up, head into the other guides to start building:

• Swaps

• Providing Liquidity

• Flashloans

• Custom Plugins