/better-auth

name: better-auth
description: Use when implementing Next.js authentication with Better Auth — OAuth, 2FA, magic links, SSO, Stripe billing, or session management.
versions:
  better-auth: 1.2
user-invocable: true
references: references/installation.md, references/basic-usage.md, references/comparison.md, references/server-config.md, references/client.md, references/session.md, references/middleware.md, references/server-actions.md, references/hooks.md, references/email.md, references/rate-limiting.md, references/cli.md, references/security.md, references/api.md, references/migrations.md, references/typescript.md, references/user-accounts.md, references/errors.md, references/telemetry.md, references/faq.md, references/concepts/sessions.md, references/concepts/database.md, references/concepts/plugins.md, references/concepts/users.md, references/concepts/oauth.md, references/concepts/security.md, references/concepts/cookies.md, references/adapters/prisma.md, references/adapters/drizzle.md, references/adapters/mongodb.md, references/adapters/sql-databases.md, references/adapters/community-adapters.md, references/providers/overview.md, references/providers/google.md, references/providers/github.md, references/providers/discord.md, references/providers/apple.md, references/providers/microsoft.md, references/providers/social-providers.md, references/providers/generic-oauth.md, references/providers/oauth-providers-all.md, references/plugins/overview.md, references/plugins/2fa.md, references/plugins/admin.md, references/plugins/organization.md, references/plugins/passkey.md, references/plugins/magic-link.md, references/plugins/email-otp.md, references/plugins/phone.md, references/plugins/anonymous.md, references/plugins/username.md, references/plugins/sso.md, references/plugins/jwt.md, references/plugins/bearer.md, references/plugins/multi-session.md, references/plugins/oidc-provider.md, references/plugins/api-key.md, references/plugins/captcha.md, references/plugins/stripe.md, references/plugins/polar.md, references/plugins/scim.md, references/plugins/siwe.md, references/plugins/device-auth.md, references/integrations/nextjs.md, references/integrations/other-frameworks.md, references/integrations/frameworks-all.md, references/examples/nextjs-app-router.md, references/examples/oauth-complete.md, references/examples/2fa-complete.md, references/examples/organization-complete.md, references/examples/passkey-complete.md, references/guides/performance.md, references/guides/plugin-development.md, references/guides/saml-okta.md, references/guides/database-adapter.md, references/guides/auth0-migration.md, references/guides/clerk-migration.md, references/guides/authjs-migration.md, references/guides/supabase-migration.md, references/guides/workos-migration.md, references/guides/browser-extension.md
related-skills: nextjs-16, prisma-7, solid-nextjs

<objective> Implements Better Auth, a TypeScript-first authentication library, in a Next.js 16 App Router project: server config, client (`createAuthClient`), session management, and the `app/api/auth/[...all]/route.ts` handler, plus `proxy.ts` for route protection (replacing middleware).

Covers the full surface — 40+ OAuth providers (Google, GitHub, Discord, Apple, Microsoft, and more), 20+ plugins (2FA, magic links, passkeys, organizations/multi-tenant, enterprise SSO/SAML, SCIM provisioning, Stripe/Polar billing, JWT/Bearer, API keys), and database adapters (Prisma, Drizzle, MongoDB, raw SQL). Also covers migration paths from Auth.js, Clerk, Auth0, Supabase, and WorkOS. While Better Auth itself is framework-agnostic, this skill's architecture guidance (proxy.ts, App Router API route) is Next.js-specific — for Prisma schema/query details see prisma-7. </objective>

Better Auth - Complete Authentication

TypeScript-first authentication library with 40+ OAuth providers and 20+ plugins.

Agent Workflow (MANDATORY)

Before ANY implementation, use `TeamCreate` to spawn 3 agents:

1. **fuse-ai-pilot:explore-codebase** - Analyze existing auth setup and patterns 2. **fuse-ai-pilot:research-expert** - Verify latest Better Auth docs via Context7/Exa 3. **mcp__context7__query-docs** - Check providers/plugins availability

After implementation, run **fuse-ai-pilot:sniper** for validation.

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Overview

When to Use

• Implementing authentication in TypeScript/JavaScript applications
• Need OAuth providers (Google, GitHub, Discord, Apple, Microsoft, etc.)
• Adding 2FA, magic links, passkeys, or phone authentication
• Enterprise SSO with SAML, SCIM provisioning, or organizations
• Integrating payments with Stripe or Polar subscriptions
• Web3 authentication with Sign-In with Ethereum (SIWE)
• Migrating from Auth.js, Clerk, Auth0, Supabase, or WorkOS

Why Better Auth

| Feature | Benefit | |---------|---------| | Framework agnostic | Next.js, SvelteKit, Nuxt, Remix, Astro, Expo, NestJS | | Plugin architecture | Add only the features you need (20+ plugins) | | Full TypeScript | End-to-end type safety, inference included | | Self-hosted | Your data stays on your infrastructure | | Database flexible | Prisma, Drizzle, MongoDB, PostgreSQL, MySQL, SQLite | | Enterprise ready | SSO, SCIM, organizations, audit logs |

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Coverage

OAuth Providers (40+)

Google, GitHub, Discord, Apple, Microsoft, Slack, Spotify, Twitter/X, Facebook, LinkedIn, GitLab, Bitbucket, Dropbox, Twitch, Reddit, TikTok, and 25+ more documented in [providers/](references/providers/).

Plugins (20+)

| Plugin | Purpose | |--------|---------| | 2FA | TOTP authenticator, backup codes | | Magic Link | Passwordless email login | | Passkey | WebAuthn biometric authentication | | Organization | Multi-tenant, roles, invitations | | SSO | Enterprise SAML/OIDC single sign-on | | SCIM | Directory sync, user provisioning | | Stripe | Subscription billing integration | | API Key | Machine-to-machine authentication | | JWT/Bearer | Token-based API authentication |

Database Adapt