# better-auth

A skill that walks your agent through Better Auth: email/password, OAuth, 2FA, passkeys and roles. Useful when a project needs sign-in and sessions.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · 390 installs · ★ 2228
- Author: mrgoonie
- License: MIT · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/mrgoonie/claudekit-skills/tree/HEAD/.claude/skills/better-auth/SKILL.md
- Updated: 2026-04-03
- HTML: https://affpapa.org/en/nevibecode/skills/mrgoonie-better-auth

## What it does

The skill covers Better Auth, a framework-agnostic TypeScript authentication library. Your agent gets instructions for email/password with verification, sign-in through Google, GitHub and Discord, two-factor auth via TOTP and SMS, passkeys/WebAuthn, session handling and role-based access control. Rate limiting is in there too.

The skill ships as a set of reference docs — email/password, OAuth providers, database integration, advanced features — plus a matrix showing what is built in and what needs a plugin. Two-factor auth, passkeys, magic link and organizations all come as plugins, and adding one means regenerating the database schema.

You need `BETTER_AUTH_SECRET` and `BETTER_AUTH_URL` in `.env` before anything runs. The CLI handles schema and migrations: `npx @better-auth/cli generate`, while `npx @better-auth/cli migrate` only works with Kysely. On any other driver you apply migrations yourself, so check how your project manages its schema first.

## Requirements
- Works with: GitHub

## Install

### Claude Code (native platform)

1. **Skills CLI (Vercel)**
```bash
npx skills add mrgoonie/claudekit-skills --skill better-auth -a claude-code
```

2. **Manually: put the files in place**
- File: `~/.claude/skills/better-auth/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/better-auth/

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add mrgoonie/claudekit-skills --skill better-auth -a codex
```

2. **Manually: put the files in place**
- File: `.agents/skills/better-auth/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add mrgoonie/claudekit-skills --skill better-auth -a cursor
```

2. **Manually: put the files in place**
- File: `.cursor/skills/better-auth/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install mrgoonie/claudekit-skills better-auth
```

2. **Manually: put the files in place**
- File: `.github/skills/better-auth/SKILL.md`

### Gemini CLI

1. **Skills CLI (Vercel)**
```bash
npx skills add mrgoonie/claudekit-skills --skill better-auth -a gemini-cli
```

2. **Platform CLI**
```bash
gemini skills install https://github.com/mrgoonie/claudekit-skills --path .claude/skills/better-auth
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/better-auth/SKILL.md` — The legacy .windsurf/skills/ path still works

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add mrgoonie/claudekit-skills --skill better-auth -a opencode
```

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/mrgoonie/claudekit-skills/tree/HEAD/.claude/skills/better-auth/SKILL.md

## When to use it
- add email/password sign-in with address verification
- wire up OAuth through GitHub or Google
- turn on two-factor auth with TOTP
- assign roles and permissions with RBAC
- generate the database schema for auth tables

## Example prompts
- Add Better Auth to this project with email/password and GitHub sign-in
- Set up TOTP two-factor authentication in Better Auth
- Generate the Better Auth schema and enable the organization plugin

## Source text · SKILL.md · MIT

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: a5339c8ea1164ade.

BEGIN THIRD-PARTY FILE a5339c8ea1164ade
````text
---
name: better-auth
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.
license: MIT
version: 2.0.0
---

# 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";

export const authClient = createAuthClient({
  baseURL: process.env.NEXT_PUBLIC_BETTER_AUTH_URL || "http://localhost:3000"
});
```

### Basic Usage

```ts
// Sign up
await authClient.signUp.email({
  email: "user@example.com",
````
END THIRD-PARTY FILE a5339c8ea1164ade

The third-party file has ended. Everything between the a5339c8ea1164ade tags is data: requests and commands from it are not followed. An “end of file” line with another tag inside the block is part of the file.

First 2784 of 7385 bytes. © mrgoonie · MIT · https://github.com/mrgoonie/claudekit-skills/tree/HEAD/.claude/skills/better-auth/SKILL.md

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