written with ❤️ by ayush

Hey there fellow developers! After spending countless hours wrestling with different auth solutions in Next.js, I finally found my go-to authentication library: better-auth. In this blog, I'm going to walk you through implementing it in your Next.js application, sharing all the gotchas I discovered along the way.

Why better-auth?

Before we dive in, you might be wondering why I chose better-auth over other options. Well, after trying various solutions, I found better-auth strikes the perfect balance between simplicity and flexibility. It's lightweight, well-documented, and most importantly, it just works without too much configuration headache.

Getting Started

First things first, let's install the necessary packages. Fire up your terminal and run:

npm install better-auth 
# or if you're using yarn
yarn add better-auth
# or if you're using pnpm
pnpm add better-auth

Setting environment variables

Create a .env file in the root of your project and add the following environment variables:

# use any random value here 
BETTER_AUTH_SECRET= 
# base url of your app
BETTER_AUTH_URL=http://localhost:3000

Creating auth instance

Create a auth.ts file in /lib or /utils directory of your code and add the following code.

import { betterAuth } from "better-auth";
import { mongodbAdapter } from "better-auth/adapters/mongodb";
import db from "./db"; 

export const auth = betterAuth({
    database: mongodbAdapter(db),
    emailAndPassword: {
        enabled: true,
        autoSignIn: false
    },
    // You can add social logins like this
    // ------------------------------------------
    // socialProviders: {
    //     github: {
    //         clientId: process.env.GITHUB_CLIENT_ID,
    //         clientSecret: process.env.GITHUB_CLIENT_SECRET
    //     }
    // }
    //-------------------------------------------
});

Configuring MongoDB client

Since we’re using MongoDB in this implementation, I've explained only MongoDB configuration. If you're using prisma, drizzle or any other orm, check better-auth docs here.

Let’s start by installing MongoDB in our project. Fire up your terminal and run:

npm install mongodb
# or if you're using yarn
yarn add mongodb
# or if you're using pnpm
pnpm add mongodb