authjs

Use when implementing authentication with Auth.js (NextAuth.js) — OAuth providers, credentials, session management, or database adapters. Also use when upgrading from NextAuth v4 to Auth.js v5 or debugging auth callback issues.

Model	Source
sonnet	pack: auth

Full Reference

┏━ 🔧 authjs ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓ ┃ Use when implementing authentication with Auth… ┃ ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛

Auth.js (NextAuth.js v5)

Auth.js v5 (beta: next-auth@beta) is the universal auth library for Next.js, SvelteKit, and Express. It replaces the v4 getServerSession(authOptions) pattern with a single auth() function that works across Server Components, Route Handlers, Server Actions, and middleware. Requires Next.js 14+.

Quick Reference

Item	Value
Current Version	v5 (beta: next-auth@beta)
Install	npm install next-auth@beta
Docs	https://authjs.dev
Min Next.js	14.0+
Required env var	AUTH_SECRET (run openssl rand -base64 32)
Session strategy	JWT (default) or database
Provider env pattern	AUTH_GITHUB_ID / AUTH_GITHUB_SECRET (auto-detected)

Reference Index

I want to…	File
Set up Auth.js in Next.js, SvelteKit, or Express	reference/setup.md
Configure OAuth, credentials, and magic link providers	reference/providers.md
Access session server-side and client-side; use JWT vs database strategy; write callbacks	reference/session.md
Protect routes with middleware or handle edge runtime split config	reference/middleware.md
Set up Prisma, Drizzle, or Supabase adapter	reference/database-adapters.md
Extend TypeScript types for session and JWT	reference/typescript.md
Migrate from NextAuth v4 to Auth.js v5	reference/v4-migration.md

Usage: Read the reference file matching your current task from the index above. Each file is self-contained with code examples and inline gotchas.