Integration of MetaMask wallet in React application

Paulina Lewandowska

19 Dec 2022
Integration of MetaMask wallet in React application

Introduction

In decentralized applications, users typically need a crypto wallet to interact with the blockchain. To enable this, developers working on the frontend layer must integrate their application with users' wallet applications. This article is intended for developers using the React library who want to create user interfaces with the popular browser plugin, MetaMask. Here is a step-by-step guide on how to integrate a React application with MetaMask.

A basic application in React

The source code of the application written for this tutarial can be found at this link. I used the following libraries to create the application:

To work with this tutorial, you can use the application provided at the link above, or you can configure the application yourself in React with the help of, for example, create-react-app or vite.

Once our application is configured, you need to make sure that we have all the necessary dependencies installed, to do this, run the command

npm install wagmi ethers

To prepare the application, I also used a component library called Material-ui, if you also want to use it, install the following packages with the command:

npm install @mui/material @emotion/react @emotion/styled

Once the configuration is complete and all the necessary dependencies are installed, we can move on to the next point.

Wagmi Library

To integrate with the MetaMask wallet application, we will use a dedicated library for React called wagmi that contains a sizable number of hooks and functions needed for daily blockchain interactions in frontend applications.

The first step will be to configure the library, to do this we need to wrap our application in a WagmiConfig component passing a client variable with our configuration:

import { WagmiConfig, createClient } from "wagmi";
import { getDefaultProvider } from "ethers";
 
import { Home } from "./pages";
import "./styles.css";
 
const client = createClient({
 autoConnect: true,
 provider: getDefaultProvider()
});
 
export default function App() {
 return (
   <WagmiConfig client={client}>
     <Home />
   </WagmiConfig>
 );
}

All available configuration options can be found at this link in the official wagmi documentation

Connecting the MetaMask wallet

Once we have completed the configuration of the wagmi library, we can move on to creating the component responsible for connecting to our wallet. The hooks available in the blibliothek will be helpful in the implementation.

To access the function that will allow us to make a request to connect the wallet, use the useConnect() hooka. To indicate that the wallet we want to connect to is MetaMask, pass the created instance of the InjectedConnector class in the configuration object to the hooka under the connecter key

import { useConnect } from "wagmi";
import { InjectedConnector } from "wagmi/dist/connectors/injected";
 
 ...
 
 const { connect } = useConnect({
   connector: new InjectedConnector()
 });
 
 ...

Hook returns us a connect function that we can call, for example, when the button is clicked.

 ...
 
<Button onClick={() => connect()}>Connect</Button>
 
 ...

To get information about the connected wallet or its connection status, you can use the useAccount() hookup, which returns us such information as:

  • the address of the connected wallet
  • whether the wallet connection action is in progress
  • whether the user's wallet is currently connected in the application
...
 
 const { address, isConnected, isConnecting } = useAccount();
 
 ...

If the user of our application managed to connect the wallet we should also allow him to disconnect it, for this we need to use the disconnect function, which we can access with the help of the hookup useDisconnect()

 ...
 
 const { disconnect } = useDisconnect();
 
 ...

With the help of these three simple hooks, we are able to handle wallet connection. The full source code of the component that handles the connection from the sample application:

import { useConnect, useDisconnect, useAccount } from "wagmi";
import { InjectedConnector } from "wagmi/dist/connectors/injected";
import { Card, Button, Heading } from "../../components";
import Typography from "@mui/material/Typography";
import { WalletInfo } from "./WalletInfo";
 
export const WalletConnect = () => {
 const { isConnected, isConnecting } = useAccount();
 
 const { connect } = useConnect({
   connector: new InjectedConnector()
 });
 
 const { disconnect } = useDisconnect();
 
 return (
   <Card>
     <Heading sx={{ mb: 2 }}>
       {isConnected ? "Your connected wallet:" : "Connect your MetaMask"}
     </Heading>
 
     {isConnecting && <Typography>Connecting...</Typography>}
 
     {isConnected ? (
       <>
         <WalletInfo />
         <Button sx={{ mt: 2 }} onClick={() => disconnect()}>
           Disconnect
         </Button>
       </>
     ) : (
       <Button
         disabled={isConnecting}
         sx={{ mt: 2 }}
         onClick={() => connect()}
       >
         Connect
       </Button>
     )}
   </Card>
 );
};

In the above example there is a <WalletInfo /> component, which we will use to display information about the connected wallet, we will deal with its creation in the next step.

Displaying information about the connected wallet

The next step will display to the user information about the connected wallet such as:

  • Wallet address
  • The current ETH balance of the wallet

To do this, we will prepare two simple components <WalletAddress/> and <WalletBalance/> and , which we will then put into the <WalletInfo/> component:

The address of the currently connected wallet

import { WalletAddress } from "./WalletAddress";
import { WalletBalance } from "./WalletBalance";
 
export const WalletInfo = () => {
 return (
   <div>
     <WalletAddress />
     <WalletBalance />
   </div>
 );
};
import { useAccount } from "wagmi";
import Typography from "@mui/material/Typography";
 
export const WalletAddress = () => {
 const { address } = useAccount();
 return (
   <Typography>
     <strong>Address: </strong>
     {address}
   </Typography>
 );
};

In order to display the connected wallet, we will use the previously mentioned useAccount() hookup, which returns us the address variable. The implementation of a simple component to display the address looks like this:

import { useAccount } from "wagmi";
import Typography from "@mui/material/Typography";
 
export const WalletAddress = () => {
 const { address } = useAccount();
 return (
   <Typography>
     <strong>Address: </strong>
     {address}
   </Typography>
 );
};

Balance of the currently connected wallet

The wagmi library also has a useBalance() hook, which will make the process of retrieving the current wallet balance much easier for us. The process of fetching this value from the blockchain is asynchronous, so this hook returns on, among other things, such information in variables as:

  • isLoading - whether the balance download is in progress
  • isFetched - whether the wallet's balance has been downloaded
  • isError - whether an error occurred while downloading the data
  • data - object containing such fields as:
    • value - user balance in WEI units
    • formatted - user's balance formatted to ETH units
    • symbol - Symbol of the asset for which the balance was downloaded
    • decimals - the number of decimal places that the number describing the quantity of the asset can have

For a better understanding of what a WEI, ETH unit or decimals parameter is, I encourage you to read these articles:

To indicate for which wallet we want to retrieve the balance of funds, we need to pass the address of this wallet as a parameter when calling the hookah as follows, to do this we can use the useAccount() hookah again from the previous step:

 ...
 
 const { address } = useAccount();
 const { isLoading, isFetched, isError, data } = useBalance({ address });
 
 ...

With this information, we are able to implement an entire component with support for the data loading process:

import { useAccount, useBalance } from "wagmi";
import Typography from "@mui/material/Typography";
import Skeleton from "@mui/material/Skeleton";
 
export const WalletBalance = () => {
 const { address } = useAccount();
 const { isLoading, isFetched, isError, data } = useBalance({ address });
 
 return (
   <Typography>
     {isLoading && <Skeleton width={200} />}
     {isFetched && (
       <>
         <strong>Balance: </strong>
         {data?.formatted} {data?.symbol}
       </>
     )}
     {isError && "Fetching balance failed!"}
   </Typography>
 );
};

Summary

The application presented here is just an example, in production applications developers often have to deal with integrating multiple wallet applications, supporting connectivity on multiple blockchain networks, and interactions of connected wallets with smart contracts. All of these functionalities and much more are supported by the wagmi library presented in this turorial. Therefore, I encourage you to study the documentation of this library to see what capabilities it offers.

Tagi

Most viewed


Never miss a story

Stay updated about Nextrope news as it happens.

You are subscribed

AI-Driven Frontend Automation: Elevating Developer Productivity to New Heights

Gracjan Prusik

11 Mar 2025
AI-Driven Frontend Automation: Elevating Developer Productivity to New Heights

AI Revolution in the Frontend Developer's Workshop

In today's world, programming without AI support means giving up a powerful tool that radically increases a developer's productivity and efficiency. For the modern developer, AI in frontend automation is not just a curiosity, but a key tool that enhances productivity. From automatically generating components, to refactoring, and testing – AI tools are fundamentally changing our daily work, allowing us to focus on the creative aspects of programming instead of the tedious task of writing repetitive code. In this article, I will show how these tools are most commonly used to work faster, smarter, and with greater satisfaction.

This post kicks off a series dedicated to the use of AI in frontend automation, where we will analyze and discuss specific tools, techniques, and practical use cases of AI that help developers in their everyday tasks.

AI in Frontend Automation – How It Helps with Code Refactoring

One of the most common uses of AI is improving code quality and finding errors. These tools can analyze code and suggest optimizations. As a result, we will be able to write code much faster and significantly reduce the risk of human error.

How AI Saves Us from Frustrating Bugs

Imagine this situation: you spend hours debugging an application, not understanding why data isn't being fetched. Everything seems correct, the syntax is fine, yet something isn't working. Often, the problem lies in small details that are hard to catch when reviewing the code.

Let’s take a look at an example:

function fetchData() {
    fetch("htts://jsonplaceholder.typicode.com/posts")
      .then((response) => response.json())
      .then((data) => console.log(data))
      .catch((error) => console.error(error));
}

At first glance, the code looks correct. However, upon running it, no data is retrieved. Why? There’s a typo in the URL – "htts" instead of "https." This is a classic example of an error that could cost a developer hours of frustrating debugging.

When we ask AI to refactor this code, not only will we receive a more readable version using newer patterns (async/await), but also – and most importantly – AI will automatically detect and fix the typo in the URL:

async function fetchPosts() {
    try {
      const response = await fetch(
        "https://jsonplaceholder.typicode.com/posts"
      );
      const data = await response.json();
      console.log(data);
    } catch (error) {
      console.error(error);
    }
}

How AI in Frontend Automation Speeds Up UI Creation

One of the most obvious applications of AI in frontend development is generating UI components. Tools like GitHub Copilot, ChatGPT, or Claude can generate component code based on a short description or an image provided to them.

With these tools, we can create complex user interfaces in just a few seconds. Generating a complete, functional UI component often takes less than a minute. Furthermore, the generated code is typically error-free, includes appropriate animations, and is fully responsive, adapting to different screen sizes. It is important to describe exactly what we expect.

Here’s a view generated by Claude after entering the request: “Based on the loaded data, display posts. The page should be responsive. The main colors are: #CCFF89, #151515, and #E4E4E4.”

Generated posts view

AI in Code Analysis and Understanding

AI can analyze existing code and help understand it, which is particularly useful in large, complex projects or code written by someone else.

Example: Generating a summary of a function's behavior

Let’s assume we have a function for processing user data, the workings of which we don’t understand at first glance. AI can analyze the code and generate a readable explanation:

function processUserData(users) {
  return users
    .filter(user => user.isActive) // Checks the `isActive` value for each user and keeps only the objects where `isActive` is true
    .map(user => ({ 
      id: user.id, // Retrieves the `id` value from each user object
      name: `${user.firstName} ${user.lastName}`, // Creates a new string by combining `firstName` and `lastName`
      email: user.email.toLowerCase(), // Converts the email address to lowercase
    }));
}

In this case, AI not only summarizes the code's functionality but also breaks down individual operations into easier-to-understand segments.

AI in Frontend Automation – Translations and Error Detection

Every frontend developer knows that programming isn’t just about creatively building interfaces—it also involves many repetitive, tedious tasks. One of these is implementing translations for multilingual applications (i18n). Adding translations for each key in JSON files and then verifying them can be time-consuming and error-prone.

However, AI can significantly speed up this process. Using ChatGPT, DeepSeek, or Claude allows for automatic generation of translations for the user interface, as well as detecting linguistic and stylistic errors.

Example:

We have a translation file in JSON format:

{
  "welcome_message": "Welcome to our application!",
  "logout_button": "Log out",
  "error_message": "Something went wrong. Please try again later."
}

AI can automatically generate its Polish version:

{
  "welcome_message": "Witaj w naszej aplikacji!",
  "logout_button": "Wyloguj się",
  "error_message": "Coś poszło nie tak. Spróbuj ponownie później."
}

Moreover, AI can detect spelling errors or inconsistencies in translations. For example, if one part of the application uses "Log out" and another says "Exit," AI can suggest unifying the terminology.

This type of automation not only saves time but also minimizes the risk of human errors. And this is just one example – AI also assists in generating documentation, writing tests, and optimizing performance, which we will discuss in upcoming articles.

Summary

Artificial intelligence is transforming the way frontend developers work daily. From generating components and refactoring code to detecting errors, automating testing, and documentation—AI significantly accelerates and streamlines the development process. Without these tools, we would lose a lot of valuable time, which we certainly want to avoid.

In the next parts of this series, we will cover topics such as:

Stay tuned to keep up with the latest insights!

The Ultimate Web3 Backend Guide: Supercharge dApps with APIs

Tomasz Dybowski

04 Mar 2025
The Ultimate Web3 Backend Guide: Supercharge dApps with APIs

Introduction

Web3 backend development is essential for building scalable, efficient and decentralized applications (dApps) on EVM-compatible blockchains like Ethereum, Polygon, and Base. A robust Web3 backend enables off-chain computations, efficient data management and better security, ensuring seamless interaction between smart contracts, databases and frontend applications.

Unlike traditional Web2 applications that rely entirely on centralized servers, Web3 applications aim to minimize reliance on centralized entities. However, full decentralization isn't always possible or practical, especially when it comes to high-performance requirements, user authentication or storing large datasets. A well-structured backend in Web3 ensures that these limitations are addressed, allowing for a seamless user experience while maintaining decentralization where it matters most.

Furthermore, dApps require efficient backend solutions to handle real-time data processing, reduce latency, and provide smooth user interactions. Without a well-integrated backend, users may experience delays in transactions, inconsistencies in data retrieval, and inefficiencies in accessing decentralized services. Consequently, Web3 backend development is a crucial component in ensuring a balance between decentralization, security, and functionality.

This article explores:

  • When and why Web3 dApps need a backend
  • Why not all applications should be fully on-chain
  • Architecture examples of hybrid dApps
  • A comparison between APIs and blockchain-based logic

This post kicks off a Web3 backend development series, where we focus on the technical aspects of implementing Web3 backend solutions for decentralized applications.

Why Do Some Web3 Projects Need a Backend?

Web3 applications seek to achieve decentralization, but real-world constraints often necessitate hybrid architectures that include both on-chain and off-chain components. While decentralized smart contracts provide trustless execution, they come with significant limitations, such as high gas fees, slow transaction finality, and the inability to store large amounts of data. A backend helps address these challenges by handling logic and data management more efficiently while still ensuring that core transactions remain secure and verifiable on-chain.

Moreover, Web3 applications must consider user experience. Fully decentralized applications often struggle with slow transaction speeds, which can negatively impact usability. A hybrid backend allows for pre-processing operations off-chain while committing final results to the blockchain. This ensures that users experience fast and responsive interactions without compromising security and transparency.

While decentralization is a core principle of blockchain technology, many dApps still rely on a Web2-style backend for practical reasons:

1. Performance & Scalability in Web3 Backend Development

  • Smart contracts are expensive to execute and require gas fees for every interaction.
  • Offloading non-essential computations to a backend reduces costs and improves performance.
  • Caching and load balancing mechanisms in traditional backends ensure smooth dApp performance and improve response times for dApp users.
  • Event-driven architectures using tools like Redis or Kafka can help manage asynchronous data processing efficiently.

2. Web3 APIs for Data Storage and Off-Chain Access

  • Storing large amounts of data on-chain is impractical due to high costs.
  • APIs allow dApps to store & fetch off-chain data (e.g. user profiles, transaction history).
  • Decentralized storage solutions like IPFS, Arweave and Filecoin can be used for storing immutable data (e.g. NFT metadata), but a Web2 backend helps with indexing and querying structured data efficiently.

3. Advanced Logic & Data Aggregation in Web3 Backend

  • Some dApps need complex business logic that is inefficient or impossible to implement in a smart contract.
  • Backend APIs allow for data aggregation from multiple sources, including oracles (e.g. Chainlink) and off-chain databases.
  • Middleware solutions like The Graph help in indexing blockchain data efficiently, reducing the need for on-chain computation.

4. User Authentication & Role Management in Web3 dApps

  • Many applications require user logins, permissions or KYC compliance.
  • Blockchain does not natively support session-based authentication, requiring a backend for handling this logic.
  • Tools like Firebase Auth, Auth0 or Web3Auth can be used to integrate seamless authentication for Web3 applications.

5. Cost Optimization with Web3 APIs

  • Every change in a smart contract requires a new audit, costing tens of thousands of dollars.
  • By handling logic off-chain where possible, projects can minimize expensive redeployments.
  • Using layer 2 solutions like Optimism, Arbitrum and zkSync can significantly reduce gas costs.

Web3 Backend Development: Tools and Technologies

A modern Web3 backend integrates multiple tools to handle smart contract interactions, data storage, and security. Understanding these tools is crucial to developing a scalable and efficient backend for dApps. Without the right stack, developers may face inefficiencies, security risks, and scaling challenges that limit the adoption of their Web3 applications.

Unlike traditional backend development, Web3 requires additional considerations, such as decentralized authentication, smart contract integration, and secure data management across both on-chain and off-chain environments.

Here’s an overview of the essential Web3 backend tech stack:

1. API Development for Web3 Backend Services

  • Node.js is the go-to backend runtime good for Web3 applications due to its asynchronous event-driven architecture.
  • NestJS is a framework built on top of Node.js, providing modular architecture and TypeScript support for structured backend development.

2. Smart Contract Interaction Libraries for Web3 Backend

  • Ethers.js and Web3.js are TypeScript/JavaScript libraries used for interacting with Ethereum-compatible blockchains.

3. Database Solutions for Web3 Backend

  • PostgreSQL: Structured database used for storing off-chain transactional data.
  • MongoDB: NoSQL database for flexible schema data storage.
  • Firebase: A set of tools used, among other things, for user authentication.
  • The Graph: Decentralized indexing protocol used to query blockchain data efficiently.

4. Cloud Services and Hosting for Web3 APIs

When It Doesn't Make Sense to Go Fully On-Chain

Decentralization is valuable, but it comes at a cost. Fully on-chain applications suffer from performance limitations, high costs and slow execution speeds. For many use cases, a hybrid Web3 architecture that utilizes a mix of blockchain-based and off-chain components provides a more scalable and cost-effective solution.

In some cases, forcing full decentralization is unnecessary and inefficient. A hybrid Web3 architecture balances decentralization and practicality by allowing non-essential logic and data storage to be handled off-chain while maintaining trustless and verifiable interactions on-chain.

The key challenge when designing a hybrid Web3 backend is ensuring that off-chain computations remain auditable and transparent. This can be achieved through cryptographic proofs, hash commitments and off-chain data attestations that anchor trust into the blockchain while improving efficiency.

For example, Optimistic Rollups and ZK-Rollups allow computations to happen off-chain while only submitting finalized data to Ethereum, reducing fees and increasing throughput. Similarly, state channels enable fast, low-cost transactions that only require occasional settlement on-chain.

A well-balanced Web3 backend architecture ensures that critical dApp functionalities remain decentralized while offloading resource-intensive tasks to off-chain systems. This makes applications cheaper, faster and more user-friendly while still adhering to blockchain's principles of transparency and security.

Example: NFT-based Game with Off-Chain Logic

Imagine a Web3 game where users buy, trade and battle NFT-based characters. While asset ownership should be on-chain, other elements like:

  • Game logic (e.g., matchmaking, leaderboard calculations)
  • User profiles & stats
  • Off-chain notifications

can be handled off-chain to improve speed and cost-effectiveness.

Architecture Diagram

Below is an example diagram showing how a hybrid Web3 application splits responsibilities between backend and blockchain components.

Hybrid Web3 Architecture

Comparing Web3 Backend APIs vs. Blockchain-Based Logic

FeatureWeb3 Backend (API)Blockchain (Smart Contracts)
Change ManagementCan be updated easilyEvery change requires a new contract deployment
CostTraditional hosting feesHigh gas fees + costly audits
Data StorageCan store large datasetsLimited and expensive storage
SecuritySecure but relies on centralized infrastructureFully decentralized & trustless
PerformanceFast response timesLimited by blockchain throughput

Reducing Web3 Costs with AI Smart Contract Audit

One of the biggest pain points in Web3 development is the cost of smart contract audits. Each change to the contract code requires a new audit, often costing tens of thousands of dollars.

To address this issue, Nextrope is developing an AI-powered smart contract auditing tool, which:

  • Reduces audit costs by automating code analysis.
  • Speeds up development cycles by catching vulnerabilities early.
  • Improves security by providing quick feedback.

This AI-powered solution will be a game-changer for the industry, making smart contract development more cost-effective and accessible.

Conclusion

Web3 backend development plays a crucial role in scalable and efficient dApps. While full decentralization is ideal in some cases, many projects benefit from a hybrid architecture, where off-chain components optimize performance, reduce costs and improve user experience.

In future posts in this Web3 backend series, we’ll explore specific implementation details, including:

  • How to design a Web3 API for dApps
  • Best practices for integrating backend services
  • Security challenges and solutions

Stay tuned for the next article in this series!