# Better Auth

Implement authentication and authorization with Better Auth - a framework-agnostic...

- Repository: https://github.com/mrgoonie/claudekit-skills (2229 stars)
- Category: Data and ML
- License: MIT
- Last updated: 2026-04-03
- Runs scripts: yes, review before use

## Install

Claude Code: `npx skills add mrgoonie/claudekit-skills --skill better-auth -g -a claude-code -y`
Codex: `npx skills add mrgoonie/claudekit-skills --skill better-auth -g -a codex -y`
Cursor: `npx skills add mrgoonie/claudekit-skills --skill better-auth -g -a cursor -y`
Gemini CLI: `npx skills add mrgoonie/claudekit-skills --skill better-auth -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add mrgoonie/claudekit-skills`

## Description

Implement authentication and authorization with Better Auth - a framework-agnostic TypeScript authentication framework. Features include email/password authentication with verification, OAuth providers (Google, GitHub, Discord, etc.), two-factor authentication (TOTP, SMS), passkeys/WebAuthn support, session management, role-based access control (RBAC), rate limiting, and database adapters. Use when adding authentication to applications, implementing OAuth flows, setting up 2FA/MFA, managing user sessions, configuring authorization rules, or building secure authentication systems for web applications.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Better Auth Skill

Better Auth is comprehensive, framework-agnostic authentication/authorization framework for TypeScript with built-in email/password, social OAuth, and powerful plugin ecosystem for advanced features.

## When to Use

- Implementing auth in TypeScript/JavaScript applications
- Adding email/password or social OAuth authentication
- Setting up 2FA, passkeys, magic links, advanced auth features
- Building multi-tenant apps with organization support
- Managing sessions and user lifecycle
- Working with any framework (Next.js, Nuxt, SvelteKit, Remix, Astro, Hono, Express, etc.)

## Quick Start

### Installation

```bash
npm install better-auth
# or pnpm/yarn/bun add better-auth
```

### Environment Setup

Create `.env`:
```env
BETTER_AUTH_SECRET=<generated-secret-32-chars-min>
BETTER_AUTH_URL=http://localhost:3000
```

### Basic Server Setup

Create `auth.ts` (root, lib/, utils/, or under src/app/server/):

```ts
import { betterAuth } from "better-auth";

export const auth = betterAuth({
  database: {
    // See references/database-integration.md
  },
  emailAndPassword: {
    enabled: true,
    autoSignIn: true
  },
  socialProviders: {
    github: {
      clientId: process.env.GITHUB_CLIENT_ID!,
      clientSecret: process.env.GITHUB_CLIENT_SECRET!,
    }
  }
});
```

### Database Schema

```bash
npx @better-auth/cli generate  # Generate schema/migrations
npx @better-auth/cli migrate   # Apply migrations (Kysely only)
```

### Mount API Handler

**Next.js App Router:**
```ts
// app/api/auth/[...all]/route.ts
import { auth } from "@/lib/auth";
import { toNextJsHandler } from "better-auth/next-js";

export const { POST, GET } = toNextJsHandler(auth);
```

**Other frameworks:** See references/email-password-auth.md#framework-setup

### Client Setup

Create `auth-client.ts`:

```ts
import { createAuthClient } from "better-auth/client";

The rest: https://github.com/mrgoonie/claudekit-skills/blob/HEAD/.claude/skills/better-auth/SKILL.md