How To Create Your Own Memecoin With Solidity and Uniswap

In this tutorial, you'll learn how to create a permissionless ERC20 memecoin using Solidity and deploy it with a Uniswap v3 liquidity pool, enabling users to trade it on decentralized exchanges.

Disclaimer: This guide is for educational purposes only. Avoid speculative investments in memecoins.

Solidity Memecoin Code Overview

Prerequisites

To follow along, ensure you have:

• Git
• Node.js
• Basic understanding of Ethereum smart contracts

Setup Instructions

Clone the repository and install dependencies:

git clone https://github.com/jamesbachini/Memecoin.git  
npm install hardhat  
npm install --save-dev "hardhat@^2.12.2" "@nomicfoundation/hardhat-toolbox@^2.0.0"  
npm install --save-dev dotenv  
npm install --save-dev @openzeppelin/contracts  
npx hardhat test  

Code Breakdown

The Meme contract combines ERC20 token functionality with Uniswap v3 liquidity pool deployment:

// SPDX-License-Identifier: MIT  
pragma solidity >=0.8.18;  
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";  

interface INonfungiblePositionManager {  
    struct MintParams {  
        address token0;  
        address token1;  
        uint24 fee;  
        int24 tickLower;  
        int24 tickUpper;  
        uint256 amount0Desired;  
        uint256 amount1Desired;  
        uint256 amount0Min;  
        uint256 amount1Min;  
        address recipient;  
        uint256 deadline;  
    }  
    function mint(MintParams calldata params) external payable returns (  
        uint256 tokenId,  
        uint128 liquidity,  
        uint256 amount0,  
        uint256 amount1  
    );  
    function createAndInitializePoolIfNecessary(  
        address token0,  
        address token1,  
        uint24 fee,  
        uint160 sqrtPriceX96  
    ) external payable returns (address pool);  
}  

contract Meme is ERC20 {  
    INonfungiblePositionManager posMan = INonfungiblePositionManager(0xC36442b4a4522E871399CD717aBDD847Ab11FE88);  
    address constant weth = 0x9c3C9283D3e44854697Cd22D3Faa240Cfb032889; // Polygon Mumbai testnet  
    uint supply = 1_000_000 * 10 ** decimals();  
    uint24 constant fee = 500;  
    uint160 constant sqrtPriceX96 = 79228162514264337593543950336; // ~1:1 price ratio  
    int24 minTick;  
    int24 maxTick;  
    address public pool;  
    address token0;  
    address token1;  
    uint amount0Desired;  
    uint amount1Desired;  

    constructor() ERC20("Meme Token", "MEME") {  
        _mint(address(this), supply);  
        fixOrdering();  
        pool = posMan.createAndInitializePoolIfNecessary(token0, token1, fee, sqrtPriceX96);  
    }  

    function addLiquidity() public {  
        IERC20(address(this)).approve(address(posMan), supply);  
        posMan.mint(INonfungiblePositionManager.MintParams({  
            token0: token0,  
            token1: token1,  
            fee: fee,  
            tickLower: minTick,  
            tickUpper: maxTick,  
            amount0Desired: amount0Desired,  
            amount1Desired: amount1Desired,  
            amount0Min: 0,  
            amount1Min: 0,  
            recipient: address(this),  
            deadline: block.timestamp + 1200  
        }));  
    }  

    function fixOrdering() private {  
        if (address(this) < weth) {  
            token0 = address(this);  
            token1 = weth;  
            amount0Desired = supply;  
            amount1Desired = 0;  
            minTick = 0;  
            maxTick = 887270;  
        } else {  
            token0 = weth;  
            token1 = address(this);  
            amount0Desired = 0;  
            amount1Desired = supply;  
            minTick = -887270;  
            maxTick = 0;  
        }  
    }  
}  

Key Features

1. Token Creation: Mints 1 million MEME tokens.
2. Liquidity Pool: Initializes a Uniswap v3 pool with a 1:1 price ratio.
3. Fair Launch: Tokens are locked in the contract, ensuring no pre-sale advantages.

Deployment Steps

1. Configure Environment

   • Update .env-sample with your Alchemy API key and wallet details.
   • Verify weth address for your target network (e.g., Uniswap’s deployment docs).

2. Deploy the Contract
   Run the following command (replace mumbai with your network):

   npx hardhat run ./scripts/deploy.js --network mumbai  

3. Add Liquidity
   Call addLiquidity() after deployment to finalize the pool.
4. Trade on Uniswap
   Users can swap tokens by entering the contract address in Uniswap’s interface.

👉 Explore Uniswap v3 liquidity strategies

FAQ

Q1: Can I deploy this on mainnet?
Yes, but use testnets like Mumbai or Goerli for practice first.

Q2: Why is addLiquidity() separate from the constructor?
Pool initialization and liquidity addition require sequential transactions due to contract interdependencies.

Q3: How do I update token metadata?
Modify the ERC20("Meme Token", "MEME") constructor arguments before deploying.

Q4: What’s the role of sqrtPriceX96?
It sets the initial token price (1:1 with ETH/MATIC in this case).

Q5: Is the liquidity pool permanent?
Yes—the LP NFT is held by the contract, preventing liquidity removal.

Final Notes

Creating a memecoin is technically simple, but success hinges on community engagement and meme culture. Always prioritize security and transparency.

👉 Learn advanced DeFi tokenomics

For further reading, refer to Uniswap’s official documentation.