mcpbeat

Better Auth Best Practices

better-auth/better-auth-best-practices

Configure Better Auth server and client, set up database adapters, manage sessions, add plugins, and handle environment variables. Use when users mention Better Auth, betterauth, auth.ts, or need to set up TypeScript authentication with email/password, OAuth, or plugin configuration.

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Install

one command, takes just this skill from the repository
npx skills add https://github.com/better-auth/skills --skill better-auth-best-practices

The instruction itself

18 sections, as written by the author

Better Auth Integration Guide

Always consult better-auth.com/docs for code examples and latest API.


Setup Workflow

  • Install: npm install better-auth
  • Set env vars: BETTER_AUTH_SECRET and BETTER_AUTH_URL
  • Create auth.ts with database + config
  • Create route handler for your framework
  • Run migrations:
  • Built-in adapter: npx @better-auth/cli@latest migrate
  • Drizzle: npx @better-auth/cli@latest generate --output src/db/auth-schema.ts then npx drizzle-kit push (dev) or npx drizzle-kit generate && npx drizzle-kit migrate (prod)
  • Prisma: npx @better-auth/cli@latest generate --output prisma/schema.prisma then npx prisma migrate dev
  • Verify: call GET /api/auth/ok — should return { status: "ok" }

Quick Reference

Environment Variables

  • BETTER_AUTH_SECRET - Encryption secret (min 32 chars). Generate: openssl rand -base64 32
  • BETTER_AUTH_URL - Base URL (e.g., https://example.com)

Only define baseURL/secret in config if env vars are NOT set.

File Location

CLI looks for auth.ts in: ./, ./lib, ./utils, or under ./src. Use --config for custom path.

CLI Commands

  • npx @better-auth/cli@latest migrate - Apply schema (built-in adapter)
  • npx @better-auth/cli@latest generate - Generate schema for Prisma/Drizzle
  • npx @better-auth/cli mcp --cursor - Add MCP to AI tools

Re-run after adding/changing plugins.


Core Config Options

| Option | Notes |

|--------|-------|

| appName | Optional display name |

| baseURL | Only if BETTER_AUTH_URL not set |

| basePath | Default /api/auth. Set / for root. |

| secret | Only if BETTER_AUTH_SECRET not set |

| database | Required for most features. See adapters docs. |

| secondaryStorage | Redis/KV for sessions & rate limits |

| emailAndPassword | { enabled: true } to activate |

| socialProviders | { google: { clientId, clientSecret }, ... } |

| plugins | Array of plugins |

| trustedOrigins | CSRF whitelist |


Database

Direct connections: Pass pg.Pool, mysql2 pool, better-sqlite3, or bun:sqlite instance. For Postgres, also supports postgres (postgres.js) and @neondatabase/serverless.

ORM adapters: Import from better-auth/adapters/drizzle, better-auth/adapters/prisma, better-auth/adapters/mongodb.

Drizzle provider values: "pg" (PostgreSQL), "mysql" (MySQL), "sqlite" (SQLite). Must match the driver used.

Critical: Better Auth uses adapter model names, NOT underlying table names. If Prisma model is User mapping to table users, use modelName: "user" (Prisma reference), not "users".


Session Management

Storage priority:

  • If secondaryStorage defined → sessions go there (not DB)
  • Set session.storeSessionInDatabase: true to also persist to DB
  • No database + cookieCache → fully stateless mode

Cookie cache strategies:

  • compact (default) - Base64url + HMAC. Smallest.
  • jwt - Standard JWT. Readable but signed.
  • jwe - Encrypted. Maximum security.

Key options: session.expiresIn (default 7 days), session.updateAge (refresh interval), session.cookieCache.maxAge, session.cookieCache.version (change to invalidate all sessions).


User & Account Config

User: user.modelName, user.fields (column mapping), user.additionalFields, user.changeEmail.enabled (disabled by default), user.deleteUser.enabled (disabled by default).

Account: account.modelName, account.accountLinking.enabled, account.storeAccountCookie (for stateless OAuth).

Required for registration: email and name fields.


Email Flows

  • emailVerification.sendVerificationEmail - Must be defined for verification to work
  • emailVerification.sendOnSignUp / sendOnSignIn - Auto-send triggers
  • emailAndPassword.sendResetPassword - Password reset email handler

Security

In advanced:

  • useSecureCookies - Force HTTPS cookies
  • disableCSRFCheck - ⚠️ Security risk
  • disableOriginCheck - ⚠️ Security risk
  • crossSubDomainCookies.enabled - Share cookies across subdomains
  • ipAddress.ipAddressHeaders - Custom IP headers for proxies
  • database.generateId - Custom ID generation or "serial"/"uuid"/false

Rate limiting: rateLimit.enabled, rateLimit.window, rateLimit.max, rateLimit.storage ("memory" | "database" | "secondary-storage").


Hooks

Endpoint hooks: hooks.before / hooks.after - Array of { matcher, handler }. Use createAuthMiddleware. Access ctx.path, ctx.context.returned (after), ctx.context.session.

Database hooks: databaseHooks.user.create.before/after, same for session, account. Useful for adding default values or post-creation actions.

Hook context (ctx.context): session, secret, authCookies, password.hash()/verify(), adapter, internalAdapter, generateId(), tables, baseURL.


Plugins

Import from dedicated paths for tree-shaking:

import { twoFactor } from "better-auth/plugins/two-factor"

NOT from "better-auth/plugins".

Popular plugins: twoFactor, organization, passkey, magicLink, emailOtp, username, phoneNumber, admin, apiKey, bearer, jwt, multiSession, sso, oauthProvider, oidcProvider, openAPI, genericOAuth.

Client plugins go in createAuthClient({ plugins: [...] }).


Client

Import from: better-auth/client (vanilla), better-auth/react, better-auth/vue, better-auth/svelte, better-auth/solid.

Key methods: signUp.email(), signIn.email(), signIn.social(), signOut(), useSession(), getSession(), revokeSession(), revokeSessions().


Type Safety

Infer types: typeof auth.$Infer.Session, typeof auth.$Infer.Session.user.

For separate client/server projects: createAuthClient<typeof auth>().


Common Gotchas

  • Model vs table name - Config uses ORM model name, not DB table name
  • Plugin schema - Re-run CLI after adding plugins
  • Secondary storage - Sessions go there by default, not DB
  • Cookie cache - Custom session fields NOT cached, always re-fetched
  • Stateless mode - No DB = session in cookie only, logout on cache expiry
  • Change email flow - Sends to current email first, then new email
  • Drizzle: db not initialized - drizzleAdapter(db, ...) requires a db instance from drizzle(). See create-auth skill for setup examples (node-postgres, postgres.js, Neon).
  • Drizzle: missing drizzle.config.ts - drizzle-kit commands require a drizzle.config.ts pointing to the generated schema file and DB credentials.

Resources

How to use it

Copy the folder

Take better-auth/better-auth-best-practices from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.

Install what it needs

The instructions reference npm, npx. Without those the skill loads but fails at the first command.