Batter Auth Complete Documentation

Complete Better Auth documentation in markdown format. Use when implementing authentication in TypeScript projects - covers OAuth providers (Google, GitHub, etc.), email/password, passkeys, 2FA, session management, database adapters (Prisma, Drizzle), and framework integrations (Next.js, SvelteKit, etc.).

Security Scan

This is an instruction-only documentation skill that contains Better Auth docs and the runtime instructions are coherent with that purpose (no credentials, no installs, no unexpected system access).

Purpose & Capability

The skill's name/description (Better Auth documentation) matches what is packaged: a large set of markdown/mdx reference files under references/. It does not request unrelated binaries, credentials, or config paths. (Minor nit: the top-level name includes the typo "Batter" but the SKILL.md and files are clearly for "better-auth".)

Instruction Scope

SKILL.md explicitly instructs the agent to read files under references/ and answer questions about authentication implementation. It does not instruct the agent to read other system files, access environment variables, or transmit data externally. The documentation does include examples that reference running npx/CLI commands and external URLs (e.g., GitHub, better-auth.com, an MCP URL), but those are parts of the docs and not instructions for the agent to exfiltrate data. Be aware that following those example commands as a user will perform network actions.

Install Mechanism

No install spec and no code files to execute — this is instruction-only, which is the lowest-risk install posture. Nothing is downloaded or written by the skill itself.

Credentials

The skill declares no required environment variables, no primary credential, and no config paths. The documented examples mention typical env vars used by Better Auth (e.g., GITHUB_CLIENT_ID) but those are part of the referenced documentation and not required by the skill itself.

Persistence & Privilege

The skill is not force-included (always:false) and does not request persistent privileges. Autonomous invocation (disable-model-invocation:false) is platform default and acceptable here; combined with the other factors there is no elevated privilege concern.

Assessment

This skill is a packaged copy of Better Auth documentation and is internally coherent. Before installing or using it, consider: 1) Source trust: the skill's source/homepage is unknown — if you need guarantees, prefer obtaining docs from the official project repo or website. 2) External commands/URLs in the docs: some examples call npx, CLI commands, or reference remote MCP/telemetry endpoints — do not run those commands or enable telemetry unless you trust the upstream project and understand the network interactions. 3) Telemetry: the docs describe an optional telemetry feature — ensure you do not enable telemetry or paste secrets when testing. If you require higher assurance, ask the publisher for the original upstream repository URL or a signed provenance record.

Better Auth Documentation

Complete Better Auth documentation embedded in markdown. Read from references/ to answer questions about authentication implementation, OAuth setup, database configuration, and framework integration.

Documentation Structure

All documentation is in references/ organized by topic:

Core Documentation

Getting Started

• references/introduction.mdx - What is Better Auth
• references/installation.mdx - Setup guide
• references/basic-usage.mdx - Authentication basics
• references/comparison.mdx - vs other auth libraries

Authentication Methods (references/authentication/)

OAuth providers and authentication strategies:

• google.mdx - Google OAuth
• github.mdx - GitHub OAuth
• microsoft.mdx - Microsoft/Azure AD
• apple.mdx - Apple Sign In
• discord.mdx, facebook.mdx, twitter.mdx, etc.
• email-password.mdx - Email & password auth
• magic-link.mdx - Passwordless magic links
• passkey.mdx - WebAuthn passkeys

Database Adapters (references/adapters/)

• prisma.mdx - Prisma ORM
• drizzle.mdx - Drizzle ORM
• kysely.mdx - Kysely
• mongodb.mdx - MongoDB
• pg.mdx - node-postgres

Concepts (references/concepts/)

Core authentication concepts:

• session.mdx - Session management
• oauth.mdx - OAuth flow
• database.mdx - Database schema
• rate-limit.mdx - Rate limiting
• middleware.mdx - Auth middleware
• cookies.mdx - Cookie handling

Plugins (references/plugins/)

Extension features:

• two-factor.mdx - 2FA/TOTP
• passkey.mdx - WebAuthn/passkeys
• email-verification.mdx - Email verification
• magic-link.mdx - Magic link auth
• organization.mdx - Organizations & teams
• multi-session.mdx - Multiple sessions
• anonymous.mdx - Anonymous users

Integrations (references/integrations/)

Framework-specific guides:

• next-js.mdx - Next.js integration
• sveltekit.mdx - SvelteKit
• astro.mdx - Astro
• solid-start.mdx - SolidStart

Examples (references/examples/)

Working examples:

• next-js.mdx - Complete Next.js example
• sveltekit.mdx - SvelteKit example

Guides (references/guides/)

How-to guides:

• custom-session.mdx - Custom session handling
• testing.mdx - Testing auth flows
• deployment.mdx - Production deployment

API Reference (references/reference/)

Complete API documentation.

Quick Reference

Common Tasks

Task	File to Read
Initial setup	references/installation.mdx
Email & password auth	references/authentication/email-password.mdx
Google OAuth	references/authentication/google.mdx
GitHub OAuth	references/authentication/github.mdx
Setup with Prisma	references/adapters/prisma.mdx
Setup with Drizzle	references/adapters/drizzle.mdx
Session management	references/concepts/session.mdx
Add 2FA	references/plugins/two-factor.mdx
Add passkeys	references/plugins/passkey.mdx
Next.js integration	references/integrations/next-js.mdx
Organizations/teams	references/plugins/organization.mdx
Rate limiting	references/concepts/rate-limit.mdx

When to Use This Skill

• Implementing authentication in a TypeScript project
• Setting up OAuth providers (Google, GitHub, Microsoft, etc.)
• Configuring database adapters (Prisma, Drizzle, etc.)
• Adding 2FA, passkeys, or magic links
• Managing sessions and cookies
• Integrating with Next.js, SvelteKit, or other frameworks
• Questions about auth patterns and best practices

How to Navigate

1. Start with references/introduction.mdx for overview
2. For setup: Read references/installation.mdx
3. For auth methods: Browse references/authentication/
4. For database: Check references/adapters/
5. For advanced features: See references/plugins/
6. For framework integration: Use references/integrations/

All files are .mdx (Markdown + JSX) but readable as plain markdown.