How to Use IPFS with Ethereum

IPFS (InterPlanetary File System)

It is a decentralized Storage Solution. The powerful decentralized technology, when combined with a blockchain platform like Ethereum, offers an enhanced storage solution for blockchain applications.

Below are the steps to store/retrieve data from IPFS and add the IPFS key to Ethereum smart contract.

Step 1: - Install and Set Up IPFS

Start by installing IPFS on your local machine or use a public IPFS gateway. Follow the official IPFS documentation for installation instructions and configure your IPFS node accordingly. Ensure that your IPFS node is running and accessible.

Link: https://docs.ipfs.tech/install/ipfs-desktop/

Step 2: -Develop Smart Contracts:

Create your Ethereum smart contracts using Solidity, a popular language for Ethereum smart contract development. Define the necessary functions and data structures required for interacting with IPFS. Here's an example smart contract:

pragma solidity ^0.8.0;

contract IPFSSample {
mapping(uint256 => string) private ipfsData;

function storeData(uint256 key, string memory cid) public {
ipfsData[key] = cid;
}

function retrieveData(uint256 key) public view returns (string memory) {
return ipfsData[key];
}
}

Step 3: Store Data on IPFS:

To store data on IPFS, you can use the ipfs-http-client library in Node.js. Install it using npm with the following command:

npm install ipfs-http-client

Code snippet for storing data using NodeJs

const IPFS = require('ipfs-http-client');
const ipfs = IPFS.create();

async function storeDataOnIPFS(data) {
const { cid } = await ipfs.add(data);
return cid.toString();
}

const data = 'Hello, IPFS!';
storeDataOnIPFS(data)
.then(cid => {
console.log('Data stored on IPFS with CID:', cid);
})
.catch(error => {
console.error('Error storing data on IPFS:', error);
});

Step 4: Deploy Smart Contracts to Ethereum:

Compile your smart contracts using the Solidity compiler and deploy them onto the Ethereum network of your choice. You can use tools like Truffle or Hardhat for contract compilation and deployment. Once deployed, note down the contract address for future interactions.

You may also like to explore | A Definitive Guide to Smart Contract Development Tools