@kardoe/better-auth-combo-auth

Combo authentication utility for Better Auth - sends both magic link AND OTP code in a single email.

Installation

npm install @kardoe/better-auth-combo-auth @kardoe/better-auth-aws-ses
# or
pnpm add @kardoe/better-auth-combo-auth @kardoe/better-auth-aws-ses

Usage

This package provides a sendVerificationOTP callback that wraps Better Auth's emailOTP plugin to send combo auth emails (magic link + OTP).

import { betterAuth } from "better-auth";
import { emailOTP } from "better-auth/plugins";
import { awsSESPlugin } from "@kardoe/better-auth-aws-ses";
import { createComboAuthSendVerificationOTP } from "@kardoe/better-auth-combo-auth";

const sesConfig = {
  region: process.env.AWS_SES_REGION!,
  accessKeyId: process.env.AWS_ACCESS_KEY_ID!,
  secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY!,
  fromEmail: process.env.EMAIL_FROM!,
  fromName: process.env.EMAIL_FROM_NAME!,
  appName: "My App",
  appUrl: "https://myapp.com",
  useComboAuthEmail: true,
};

export const auth = betterAuth({
  // ... your config
  plugins: [
    awsSESPlugin(sesConfig),
    emailOTP({
      sendVerificationOTP: createComboAuthSendVerificationOTP({
        sesConfig,
        baseUrl: "https://myapp.com",
        defaultCallback: "/dashboard",
        welcomeRoute: "/welcome",
        emailOTPRoute: "/verify",
      }),
    }),
  ],
});

How It Works

When a user requests an OTP (for sign-in or email verification), instead of just sending an OTP code, this utility sends an email containing:

1. Magic Link - A clickable link that auto-submits the OTP
2. OTP Code - The code that can be manually entered

The magic link encodes the OTP, email, and callback URL in a base64 payload, allowing the frontend to auto-verify the user when they click the link.

Options

| Option | Type | Default | Description | |--------|------|---------|-------------| | sesConfig | SESConfig | required | AWS SES configuration | | baseUrl | string | required | Base URL of your application | | defaultCallback | string | "/profile" | URL to redirect after authentication | | welcomeRoute | string | "/welcome" | Route for signup/welcome flow | | emailOTPRoute | string | "/email-otp" | Route for email OTP verification |

License

MIT