Create Auth Skill

Guide for adding authentication to TypeScript/JavaScript applications using Better Auth.

For code examples and syntax, see better-auth.com/docs.

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Phase 1: Planning (REQUIRED before implementation)

Before writing any code, gather requirements by scanning the project and asking the user structured questions. This ensures the implementation matches their needs.

Step 1: Scan the project

Analyze the codebase to auto-detect:

• Framework — Look for next.config, svelte.config, nuxt.config, astro.config, vite.config, or Express/Hono entry files.
• Database/ORM — Look for prisma/schema.prisma, drizzle.config, package.json deps (pg, mysql2, better-sqlite3, mongoose, mongodb).
• Existing auth — Look for existing auth libraries (next-auth, lucia, clerk, supabase/auth, firebase/auth) in package.json or imports.
• Package manager — Check for pnpm-lock.yaml, yarn.lock, bun.lockb, or package-lock.json.

Use what you find to pre-fill defaults and skip questions you can already answer.

Step 2: Ask planning questions

Use the AskQuestion tool to ask the user all applicable questions in a single call. Skip any question you already have a confident answer for from the scan. Group them under a title like "Auth Setup Planning".

Questions to ask:

1. Project type (skip if detected)

   • Prompt: "What type of project is this?"
   • Options: New project from scratch | Adding auth to existing project | Migrating from another auth library

2. Framework (skip if detected)

   • Prompt: "Which framework are you using?"
   • Options: Next.js (App Router) | Next.js (Pages Router) | SvelteKit | Nuxt | Astro | Express | Hono | SolidStart | Other

3. Database & ORM (skip if detected)

   • Prompt: "Which database setup will you use?"
   • Options: PostgreSQL (Prisma) | PostgreSQL (Drizzle) | PostgreSQL (pg driver) | MySQL (Prisma) | MySQL (Dri...