If you haven't been living under a rock you have probably heard of Web 3.0!

One of the most important parts of a full-stack is authentication. So let's see how to authorize users with their Metamask wallet in a Next.js app.

If you don't know what is metamask then check out their website

Setting up the app

Create a new next app

npx create-next-app next-metamask

Navigate into the app

cd next-metamask

Installing the required dependencies

npm i @walletconnect/web3-provider moralis react-moralis # npm

yarn add @walletconnect/web3-provider moralis react-moralis # yarn

Start the server

npm run dev # npm

yarn dev # yarn

Get Moralis Credentials

Go to moralis and signup/login. After that click on Create new Server and select TestNet Server

By selecting it you will see a popup. Fill in the details, and click the Add Instance button.

After the server is created click on view details

We are going to need the server URL and Application ID

Building out the authentication system

Adding the environment variables

Create a .env.local file in the root of your folder and add the env variables like this-

NEXT_PUBLIC_MORALIS_APP_ID=<app_id>
NEXT_PUBLIC_MORALIS_SERVER_ID=<server_id>

You need to replace the values of the variables with the credentials you got from Moralis.

Wrap the app in a MoralisProvider

Go to _app.js and wrap the <Component {...pageProps} /> with the Moralis Provider with the env variables like this-

<MoralisProvider
  appId={process.env.NEXT_PUBLIC_MORALIS_APP_ID}
  serverUrl={process.env.NEXT_PUBLIC_MORALIS_SERVER_ID}
>
  <Component {...pageProps} />
</MoralisProvider>

Now import MoralisProvider from react-moralis

import { MoralisProvider } from "react-moralis";

Creating the sign-in button
I am going to do create the login button on the home page, feel free to create it on any page you need.

Get the authenticate function from the useMoralis hook-

const { authenticate } = useMoralis();

You also need to import the hook from react-moralis

import { useMoralis } from "react-moralis";

Create a button like this-

<button
  onClick={() => {
    authenticate({ provider: "metamask" });
  }}
>
  Sign in with MetaMask
</button>

Now if we click on sign in, it will open the metamask extension for sign in.

%[https://www.loom.com/share/c2b1c9936ad44185810d9978ea5c2193]

Show signout button if the user is signed out

We need to get a few more things from the useMoralis hook like this-

const { authenticate, isAuthenticated, logout } = useMoralis();

Create a ternary operator to show the logout button, if the user is signed in otherwise show the sign-in button-

{isAuthenticated ? (
    <button
      onClick={logout}
    >
      Logout
    </button>
  ) : (
    <button
      onClick={() => {
        authenticate({ provider: "metamask" });
      }}
    >
      Sign in with MetaMask
    </button>
  );
}

Now our sign in and sign out is working 🥳🥳

Getting the user data
Let's see how to get some basic data like their eth address and username.

When the user is authenticated, you can add this fragment to show the userName and their address wallet-

<>
  <button onClick={logout}>Logout</button>
  <h2>Welcome {user.get("username")}</h2>
  <h2>Your wallet address is {user.get("ethAddress")}</h2>
</>

You need to get the user from the useMoralis hook as well-

const { authenticate, isAuthenticated, logout, user } = useMoralis();

The userName is very random 😂but it can help in some cases and the eth address can be used for transactions.

Signing off

It was this easy to implement authentication of metamask with moralis 🤯

Hope you found this tutorial useful and stay tuned for more of these web 3.0 tutorials ✌️

Useful links

GitHub repo

Moralis

Metamask

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