Nitro Integration

Better Auth can be integrated with your Nitro Application(an open source framework to build web servers).

This guide aims to help you integrate Better Auth with your Nitro application in a few simple steps.

Create a new Nitro Application

Start by scaffolding a new Nitro application using the following command:

npx giget@latest nitro nitro-app --install

This will create the nitro-app directory and install all the dependencies. You can now open the nitro-app directory in your code editor.

Prisma Adapter Setup

For this guide, we will be using the Prisma adapter. You can install prisma client by running the following command:

npm install @prisma/client

prisma can be installed as a dev dependency using the following command:

npm install -D prisma

Generate a schema.prisma file in the prisma directory by running the following command:

npx prisma init

You can now replace the contents of the schema.prisma file with the following:

generator client {
  provider = "prisma-client-js"
}
 
datasource db {
  provider = "sqlite"
  url      = env("DATABASE_URL")
}
 
// Will be deleted. Just need it to generate the prisma client
model Test {
  id   Int    @id @default(autoincrement())
  name String
}

Ensure that you update the DATABASE_URL in your .env file to point to the location of your database.

DATABASE_URL="file:./dev.db"

Run the following command to generate the Prisma client & sync the database:

npx prisma db push

Install & Configure Better Auth

Follow steps 1 & 2 from the installation guide to install Better Auth in your Nitro application & set up the environment variables.

Once that is done, create your better auth instance within the server/utils/auth.ts file.

import { betterAuth } from "better-auth";
import { prismaAdapter } from "better-auth/adapters/prisma";
import { PrismaClient } from "@prisma/client";
 
const prisma = new PrismaClient();
export const auth = betterAuth({
  database: prismaAdapter(prisma, { provider: "sqlite" }),
  emailAndPassword: { enabled: true },
});

Update Prisma Schema

Use the Better Auth CLI to update your Prisma schema with the required models by running the following command:

npx @better-auth/cli generate --config server/utils/auth.ts

Head over to the prisma/schema.prisma file & save the file to trigger the format on save.

After saving the file, you can run the npx prisma db push command to update the database schema.

Mount The Handler

You can now mount the Better Auth handler in your Nitro application. You can do this by adding the following code to your server/routes/api/auth/[...all].ts file:

export default defineEventHandler((event) => {
  return auth.handler(toWebRequest(event));
});

Cors

You can configure CORS for your Nitro app by creating a plugin.

Start by installing the cors package:

npm install cors

You can now create a new file server/plugins/cors.ts and add the following code:

import cors from "cors";
export default defineNitroPlugin((plugin) => {
  plugin.h3App.use(
    fromNodeMiddleware(
      cors({
        origin: "*",
      }),
    ),
  );
});

Auth Guard/Middleware

You can add an auth guard to your Nitro application to protect routes that require authentication. You can do this by creating a new file server/utils/require-auth.ts and adding the following code:

import { EventHandler, H3Event } from "h3";
import { fromNodeHeaders } from "better-auth/node";
 
/**
 * Middleware used to require authentication for a route.
 *
 * Can be extended to check for specific roles or permissions.
 */
export const requireAuth: EventHandler = async (event: H3Event) => {
  const headers = getRequestHeaders(event);
 
  const session = await auth.api.getSession({
    headers: fromNodeHeaders(headers),
  });
  if (!session)
    throw createError({
      statusCode: 401,
      statusMessage: "Unauthorized",
    });
  // You can save the session to the event context for later use
  event.context.auth = session;
};

You can now use this event handler/middleware in your routes to protect them:

// Object syntax of the route handler
export default defineEventHandler({
  // The user has to be logged in to access this route
  onRequest: [requireAuth],
  handler: async (event) => {
    setResponseStatus(event, 201, "Secret data");
    return { message: "Secret data" };
  },
});

Example

You can find an example of a Nitro application integrated with Better Auth & Prisma here.