Better Auth

---

name: better-auth description: | Self-hosted auth for TypeScript/Cloudflare Workers with social auth, 2FA, passkeys, organizations, RBAC, and 15+ plugins. Requires Drizzle ORM or Kysely for D1 (no direct adapter). Self-hosted alternative to Clerk/Auth.js.

Use when: self-hosting auth on D1, building OAuth provider, multi-tenant SaaS, or troubleshooting D1 adapter errors, session caching, rate limits, Expo crashes, additionalFields bugs. user-invocable: true allowed-tools: - Read - Write - Edit - Bash - Glob - Grep

---

better-auth - D1 Adapter & Error Prevention Guide

Package: better-auth@1.4.16 (Jan 21, 2026) Breaking Changes: ESM-only (v1.4.0), Admin impersonation prevention default (v1.4.6), Multi-team table changes (v1.3), D1 requires Drizzle/Kysely (no direct adapter)

---

⚠️ CRITICAL: D1 Adapter Requirement

better-auth DOES NOT have d1Adapter(). You MUST use:

Drizzle ORM (recommended): drizzleAdapter(db, { provider: "sqlite" })

Kysely: new Kysely({ dialect: new D1Dialect({ database: env.DB }) })

See Issue #1 below for details.

---

What's New in v1.4.10 (Dec 31, 2025)

Major Features:

OAuth 2.1 Provider plugin - Build your own OAuth provider (replaces MCP plugin)

Patreon OAuth provider - Social sign-in with Patreon

Kick OAuth provider - With refresh token support

Vercel OAuth provider - Sign in with Vercel

Global backgroundTasks config - Deferred actions for better performance

Form data support - Email authentication with fetch metadata fallback

Stripe enhancements - Flexible subscription lifecycle, disableRedirect option

Admin Plugin Updates:

⚠️ Breaking: Impersonation of admins disabled by default (v1.4.6)

Support role with permission-based user updates

Role type inference improvements

Security Fixes:

SAML XML parser hardening with configurable size constraints

SAML assertion timestamp validation with per-provider clock skew

SSO domain-verified provider trust

Deprecated algorithm rejection

Line nonce enforcement

📚 Docs: https://www.better-auth.com/changelogs

---

What's New in v1.4.0 (Nov 22, 2025)

Major Features:

Stateless session management - Sessions without database storage

ESM-only package ⚠️ Breaking: CommonJS no longer supported

JWT key rotation - Automatic key rotation for enhanced security

SCIM provisioning - Enterprise user provisioning protocol

@standard-schema/spec - Replaces ZodType for validation

CaptchaFox integration - Built-in CAPTCHA support

Automatic server-side IP detection

Cookie-based account data storage

Multiple passkey origins support

RP-Initiated Logout endpoint (OIDC)

📚 Docs: https://www.better-auth.com/changelogs

---

What's New in v1.3 (July 2025)

Major Features:

SSO with SAML 2.0 - Enterprise single sign-on (moved to separate @better-auth/sso package)

Multi-team support ⚠️ Breaking: teamId removed from member table, new teamMembers table required

Additional fields - Custom fields for organization/member/invitation models

Performance improvements and bug fixes

📚 Docs: https://www.better-auth.com/blog/1-3

---

Alternative: Kysely Adapter Pattern

If you prefer Kysely over Drizzle:

File: src/auth.ts

import { betterAuth } from "better-auth";
import { Kysely, CamelCasePlugin } from "kysely";
import { D1Dialect } from "kysely-d1";
type Env = {
  DB: D1Database;
  BETTER_AUTH_SECRET: string;
  // ... other env vars
};
export function createAuth(env: Env) {
  return betterAuth({
    secret: env.BETTER_AUTH_SECRET,
    // Kysely with D1Dialect
    database: {
      db: new Kysely({
        dialect: new D1Dialect({
          database: env.DB,
        }),
        plugins: [
          // CRITICAL: Required if using Drizzle schema with snake_case
          new CamelCasePlugin(),
        ],
      }),
      type: "sqlite",
    },
    emailAndPassword: {
      enabled: true,
    },
    // ... other config
  });
}

Why CamelCasePlugin?

If your Drizzle schema uses snake_case column names (e.g., email_verified), but better-auth expects camelCase (e.g., emailVerified), the CamelCasePlugin automatically converts between the two.

⚠️ Cloudflare Workers Note: D1 database bindings are only available inside the request handler (the fetch() function). You cannot initialize better-auth outside the request context. Use a factory function pattern:

// ❌ WRONG - DB binding not available outside request
const db = drizzle(env.DB, { schema }) // env.DB doesn't exist here
export const auth = betterAuth({ database: drizzleAdapter(db, { provider: "sqlite" }) })
// ✅ CORRECT - Create auth instance per-request
export default {
  fetch(request, env, ctx) {
    const db = drizzle(env.DB, { schema })
    const auth = betterAuth({ database: drizzleAdapter(db, { provider: "sqlite" }) })
    return auth.handler(request)
  }
}

Community Validation: Multiple production implementations confirm this pattern (Medium, AnswerOverflow, official Hono examples).

---

Framework Integrations

TanStack Start

⚠️ CRITICAL: TanStack Start requires the reactStartCookies plugin to handle cookie setting properly.

import { betterAuth } from "better-auth";
import { drizzleAdapter } from "better-auth/adapters/drizzle";
import { reactStartCookies } from "better-auth/react-start";
export const auth = betterAuth({
  database: drizzleAdapter(db, { provider: "sqlite" }),
  plugins: [
    twoFactor(),
    organization(),
    reactStartCookies(), // ⚠️ MUST be LAST plugin
  ],
});

Why it's needed: TanStack Start uses a special cookie handling system. Without this plugin, auth functions like signInEmail() and signUpEmail() won't set cookies properly, causing authentication to fail.

Important: The reactStartCookies plugin must be the last plugin in the array.

Session Nullability Pattern: When using useSession() in TanStack Start, the session object always exists, but session.user and session.session are null when not logged in:

const { data: session } = authClient.useSession()
// When NOT logged in:
console.log(session) // { user: null, session: null }
console.log(!!session) // true (unexpected!)
// Correct check:
if (session?.user) {
  // User is logged in
}

Always check session?.user or session?.session, not just session. This is expected behavior (session object container always exists).

API Route Setup (/src/routes/api/auth/$.ts):

import { auth } from '@/lib/auth'
import { createFileRoute } from '@tanstack/react-router'
export const Route = createFileRoute('/api/auth/$')({
  server: {
    handlers: {
      GET: ({ request }) => auth.handler(request),
      POST: ({ request }) => auth.handler(request),
    },
  },
})

📚 Official Docs: https://www.better-auth.com/docs/integrations/tanstack

---

Available Plugins (v1.4+)

Better Auth provides plugins for advanced authentication features:

| Plugin | Import | Description | Docs | |--------|--------|-------------|------| | OAuth 2.1 Provider | better-auth/plugins | Build OAuth 2.1 provider with PKCE, JWT tokens, consent flows (replaces MCP & OIDC plugins) | 📚 | | SSO | better-auth/plugins | Enterprise Single Sign-On with OIDC, OAuth2, and SAML 2.0 support | 📚 | | Stripe | better-auth/plugins | Payment and subscription management with flexible lifecycle handling | 📚 | | MCP | better-auth/plugins | ⚠️ Deprecated - Use OAuth 2.1 Provider instead | 📚 | | Expo | better-auth/expo | React Native/Expo with webBrowserOptions and last-login-method tracking | 📚 |

OAuth 2.1 Provider Plugin (New in v1.4.9)

Build your own OAuth provider for MCP servers, third-party apps, or API access:

import { betterAuth } from "better-auth";
import { oauthProvider } from "better-auth/plugins";
import { jwt } from "better-auth/plugins";
export const auth = betterAuth({
  plugins: [
    jwt(), // Required for token signing
    oauthProvider({
      // Token expiration (seconds)
      accessTokenExpiresIn: 3600,      // 1 hour
      refreshTokenExpiresIn: 2592000,  // 30 days
      authorizationCodeExpiresIn: 600, // 10 minutes
    }),
  ],
});

Key Features:

OAuth 2.1 compliant - PKCE mandatory, S256 only, no implicit flow

Three grant types: authorization_code, refresh_token, client_credentials

JWT or opaque tokens - Configurable token format

Dynamic client registration - RFC 7591 compliant

Consent management - Skip consent for trusted clients

OIDC UserInfo endpoint - /oauth2/userinfo with scope-based claims

Required Well-Known Endpoints:

// app/api/.well-known/oauth-authorization-server/route.ts
export async function GET() {
  return Response.json({
    issuer: process.env.BETTER_AUTH_URL,
    authorization_endpoint: ${process.env.BETTER_AUTH_URL}/api/auth/oauth2/authorize,
    token_endpoint: ${process.env.BETTER_AUTH_URL}/api/auth/oauth2/token,
    // ... other metadata
  });
}

Create OAuth Client:

const client = await auth.api.createOAuthClient({
  body: {
    name: "My MCP Server",
    redirectURLs: ["https://claude.ai/callback"],
    type: "public", // or "confidential"
  },
});
// Returns: { clientId, clientSecret (if confidential) }

📚 Full Docs: https://www.better-auth.com/docs/plugins/oauth-provider

⚠️ Note: This plugin is in active development and may not be suitable for production use yet.

---

Additional Plugins Reference

| Plugin | Description | Docs | |--------|-------------|------| | Bearer | API token auth (alternative to cookies for APIs) | 📚 | | One Tap | Google One Tap frictionless sign-in | 📚 | | SCIM | Enterprise user provisioning (SCIM 2.0) | 📚 | | Anonymous | Guest user access without PII | 📚 | | Username | Username-based sign-in (alternative to email) | 📚 | | Generic OAuth | Custom OAuth providers with PKCE | 📚 | | Multi-Session | Multiple accounts in same browser | 📚 | | API Key | Token-based auth with rate limits | 📚 |

#### Bearer Token Plugin

For API-only authentication (mobile apps, CLI tools, third-party integrations):

import { bearer } from "better-auth/plugins";
import { bearerClient } from "better-auth/client/plugins";
// Server
export const auth = betterAuth({
  plugins: [bearer()],
});
// Client - Store token after sign-in
const { token } = await authClient.signIn.email({ email, password });
localStorage.setItem("auth_token", token);
// Client - Configure fetch to include token
const authClient = createAuthClient({
  plugins: [bearerClient()],
  fetchOptions: {
    auth: { type: "Bearer", token: () => localStorage.getItem("auth_token") },
  },
});

#### Google One Tap Plugin

Frictionless single-tap sign-in for users already signed into Google:

import { oneTap } from "better-auth/plugins";
import { oneTapClient } from "better-auth/client/plugins";
// Server
export const auth = betterAuth({
  plugins: [oneTap()],
});
// Client
authClient.oneTap({
  onSuccess: (session) => {
    window.location.href = "/dashboard";
  },
});

Requirement: Configure authorized JavaScript origins in Google Cloud Console.

#### Anonymous Plugin

Guest access without requiring email/password:

import { anonymous } from "better-auth/plugins";
// Server
export const auth = betterAuth({
  plugins: [
    anonymous({
      emailDomainName: "anon.example.com", // temp@{id}.anon.example.com
      onLinkAccount: async ({ anonymousUser, newUser }) => {
        // Migrate anonymous user data to linked account
        await migrateUserData(anonymousUser.id, newUser.id);
      },
    }),
  ],
});
// Client
await authClient.signIn.anonymous();
// Later: user can link to real account via signIn.social/email

#### Generic OAuth Plugin

Add custom OAuth providers not in the built-in list:

import { genericOAuth } from "better-auth/plugins";
export const auth = betterAuth({
  plugins: [
    genericOAuth({
      config: [
        {
          providerId: "linear",
          clientId: env.LINEAR_CLIENT_ID,
          clientSecret: env.LINEAR_CLIENT_SECRET,
          discoveryUrl: "https://linear.app/.well-known/openid-configuration",
          scopes: ["openid", "email", "profile"],
          pkce: true, // Recommended
        },
      ],
    }),
  ],
});

Callback URL pattern: {baseURL}/api/auth/oauth2/callback/{providerId}

---

Rate Limiting

Built-in rate limiting with customizable rules:

export const auth = betterAuth({
  rateLimit: {
    window: 60,  // seconds (default: 60)
    max: 100,    // requests per window (default: 100)
    // Custom rules for sensitive endpoints
    customRules: {
      "/sign-in/email": { window: 10, max: 3 },
      "/two-factor/*": { window: 10, max: 3 },
      "/forget-password": { window: 60, max: 5 },
    },
    // Use Redis/KV for distributed systems
    storage: "secondary-storage", // or "database"
  },
  // Secondary storage for rate limiting
  secondaryStorage: {
    get: async (key) => env.KV.get(key),
    set: async (key, value, ttl) => env.KV.put(key, value, { expirationTtl: ttl }),
    delete: async (key) => env.KV.delete(key),
  },
});

Note: Server-side calls via auth.api.* bypass rate limiting.

---

Stateless Sessions (v1.4.0+)

Store sessions entirely in signed cookies without database storage:

export const auth = betterAuth({
  session: {
    // Stateless: No database storage, session lives in cookie only
    storage: undefined, // or omit entirely
    // Cookie configuration
    cookieCache: {
      enabled: true,
      maxAge: 60 * 60 * 24 * 7, // 7 days
      encoding: "jwt", // Use JWT for stateless (not "compact")
    },
    // Session expiration
    expiresIn: 60 * 60 * 24 * 7, // 7 days
  },
});

When to Use:

| Storage Type | Use Case | Tradeoffs | |--------------|----------|-----------| | Stateless (cookie-only) | Read-heavy apps, edge/serverless, no revocation needed | Can't revoke sessions, limited payload size | | D1 Database | Full session management, audit trails, revocation | Eventual consistency issues | | KV Storage | Strong consistency, high read performance | Extra binding setup |

Key Points:

Stateless sessions can't be revoked (user must wait for expiry)

Cookie size limit ~4KB (limits session data)

Use encoding: "jwt" for interoperability, "jwe" for encrypted

Server must have consistent BETTER_AUTH_SECRET across all instances

---

JWT Key Rotation (v1.4.0+)

Automatically rotate JWT signing keys for enhanced security:

import { jwt } from "better-auth/plugins";
export const auth = betterAuth({
  plugins: [
    jwt({
      // Key rotation (optional, enterprise security)
      keyRotation: {
        enabled: true,
        rotationInterval: 60 * 60 * 24 * 30, // Rotate every 30 days
        keepPreviousKeys: 3, // Keep 3 old keys for validation
      },
      // Custom signing algorithm (default: HS256)
      algorithm: "RS256", // Requires asymmetric keys
      // JWKS endpoint (auto-generated at /api/auth/jwks)
      exposeJWKS: true,
    }),
  ],
});

Key Points:

Key rotation prevents compromised key from having indefinite validity

Old keys are kept temporarily to validate existing tokens

JWKS endpoint at /api/auth/jwks for external services

Use RS256 for public key verification (microservices)

HS256 (default) for single-service apps

---

Provider Scopes Reference

Common OAuth providers and the scopes needed for user data:

| Provider | Scope | Returns | |----------|-------|---------| | Google | openid | User ID only | | | email | Email address, email_verified | | | profile | Name, avatar (picture), locale | | GitHub | user:email | Email address (may be private) | | | read:user | Name, avatar, profile URL, bio | | Microsoft | openid | User ID only | | | email | Email address | | | profile | Name, locale | | | User.Read | Full profile from Graph API | | Discord | identify | Username, avatar, discriminator | | | email | Email address | | Apple | name | First/last name (first auth only) | | | email | Email or relay address | | Patreon | identity | User ID, name | | | identity[email] | Email address | | Vercel | (auto) | Email, name, avatar |

Configuration Example:

socialProviders: {
  google: {
    clientId: env.GOOGLE_CLIENT_ID,
    clientSecret: env.GOOGLE_CLIENT_SECRET,
    scope: ["openid", "email", "profile"], // All user data
  },
  github: {
    clientId: env.GITHUB_CLIENT_ID,
    clientSecret: env.GITHUB_CLIENT_SECRET,
    scope: ["user:email", "read:user"], // Email + full profile
  },
  microsoft: {
    clientId: env.MS_CLIENT_ID,
    clientSecret: env.MS_CLIENT_SECRET,
    scope: ["openid", "email", "profile", "User.Read"],
  },
}

---

Session Cookie Caching

Three encoding strategies for session cookies:

| Strategy | Format | Use Case | |----------|--------|----------| | Compact (default) | Base64url + HMAC-SHA256 | Smallest, fastest | | JWT | Standard JWT | Interoperable | | JWE | A256CBC-HS512 encrypted | Most secure |

export const auth = betterAuth({
  session: {
    cookieCache: {
      enabled: true,
      maxAge: 300, // 5 minutes
      encoding: "compact", // or "jwt" or "jwe"
    },
    freshAge: 60 * 60 * 24, // 1 day - operations requiring fresh session
  },
});

Fresh sessions: Some sensitive operations require recently created sessions. Configure freshAge to control this window.

---

New Social Providers (v1.4.9+)

socialProviders: {
  // Patreon - Creator economy
  patreon: {
    clientId: env.PATREON_CLIENT_ID,
    clientSecret: env.PATREON_CLIENT_SECRET,
    scope: ["identity", "identity[email]"],
  },
  // Kick - Streaming platform (with refresh tokens)
  kick: {
    clientId: env.KICK_CLIENT_ID,
    clientSecret: env.KICK_CLIENT_SECRET,
  },
  // Vercel - Developer platform
  vercel: {
    clientId: env.VERCEL_CLIENT_ID,
    clientSecret: env.VERCEL_CLIENT_SECRET,
  },
}

---

Cloudflare Workers Requirements

⚠️ CRITICAL: Cloudflare Workers require AsyncLocalStorage support:

# wrangler.toml
compatibility_flags = ["nodejs_compat"]
or for older Workers:
compatibility_flags = ["nodejs_als"]

Without this flag, better-auth will fail with context-related errors.

---

Database Hooks

Execute custom logic during database operations:

export const auth = betterAuth({
  databaseHooks: {
    user: {
      create: {
        before: async (user, ctx) => {
          // Validate or modify before creation
          if (user.email?.endsWith("@blocked.com")) {
            throw new APIError("BAD_REQUEST", { message: "Email domain not allowed" });
          }
          return { data: { ...user, role: "member" } };
        },
        after: async (user, ctx) => {
          // Send welcome email, create related records, etc.
          await sendWelcomeEmail(user.email);
          await createDefaultWorkspace(user.id);
        },
      },
    },
    session: {
      create: {
        after: async (session, ctx) => {
          // Audit logging
          await auditLog.create({ action: "session_created", userId: session.userId });
        },
      },
    },
  },
});

Available hooks: create, update for user, session, account, verification tables.

---

Expo/React Native Integration

Complete mobile integration pattern:

// Client setup with secure storage
import { expoClient } from "@better-auth/expo";
import * as SecureStore from "expo-secure-store";
const authClient = createAuthClient({
  baseURL: "https://api.example.com",
  plugins: [expoClient({ storage: SecureStore })],
});
// OAuth with deep linking
await authClient.signIn.social({
  provider: "google",
  callbackURL: "myapp://auth/callback", // Deep link
});
// Or use ID token verification (no redirect)
await authClient.signIn.social({
  provider: "google",
  idToken: {
    token: googleIdToken,
    nonce: generatedNonce,
  },
});
// Authenticated requests
const cookie = await authClient.getCookie();
await fetch("https://api.example.com/data", {
  headers: { Cookie: cookie },
  credentials: "omit",
});

app.json deep link setup:

{
  "expo": {
    "scheme": "myapp"
  }
}

Server trustedOrigins (development):

trustedOrigins: ["exp://**", "myapp://"]

---

API Reference

Overview: What You Get For Free

When you call auth.handler(), better-auth automatically exposes 80+ production-ready REST endpoints at /api/auth/*. Every endpoint is also available as a server-side method via auth.api.* for programmatic use.

This dual-layer API system means:

Clients (React, Vue, mobile apps) call HTTP endpoints directly

Server-side code (middleware, background jobs) uses auth.api.* methods

Zero boilerplate - no need to write auth endpoints manually

Time savings: Building this from scratch = ~220 hours. With better-auth = ~4-8 hours. 97% reduction.

---

Auto-Generated HTTP Endpoints

All endpoints are automatically exposed at /api/auth/* when using auth.handler().

#### Core Authentication Endpoints

| Endpoint | Method | Description | |----------|--------|-------------| | /sign-up/email | POST | Register with email/password | | /sign-in/email | POST | Authenticate with email/password | | /sign-out | POST | Logout user | | /change-password | POST | Update password (requires current password) | | /forget-password | POST | Initiate password reset flow | | /reset-password | POST | Complete password reset with token | | /send-verification-email | POST | Send email verification link | | /verify-email | GET | Verify email with token (?token=) | | /get-session | GET | Retrieve current session | | /list-sessions | GET | Get all active user sessions | | /revoke-session | POST | End specific session | | /revoke-other-sessions | POST | End all sessions except current | | /revoke-sessions | POST | End all user sessions | | /update-user | POST | Modify user profile (name, image) | | /change-email | POST | Update email address | | /set-password | POST | Add password to OAuth-only account | | /delete-user | POST | Remove user account | | /list-accounts | GET | Get linked authentication providers | | /link-social | POST | Connect OAuth provider to account | | /unlink-account | POST | Disconnect provider |

#### Social OAuth Endpoints

| Endpoint | Method | Description | |----------|--------|-------------| | /sign-in/social | POST | Initiate OAuth flow (provider specified in body) | | /callback/:provider | GET | OAuth callback handler (e.g., /callback/google) | | /get-access-token | GET | Retrieve provider access token |

Example OAuth flow:

// Client initiates
await authClient.signIn.social({
  provider: "google",
  callbackURL: "/dashboard",
});
// better-auth handles redirect to Google
// Google redirects back to /api/auth/callback/google
// better-auth creates session automatically

---

#### Plugin Endpoints

##### Two-Factor Authentication (2FA Plugin)

import { twoFactor } from "better-auth/plugins";

| Endpoint | Method | Description | |----------|--------|-------------| | /two-factor/enable | POST | Activate 2FA for user | | /two-factor/disable | POST | Deactivate 2FA | | /two-factor/get-totp-uri | GET | Get QR code URI for authenticator app | | /two-factor/verify-totp | POST | Validate TOTP code from authenticator | | /two-factor/send-otp | POST | Send OTP via email | | /two-factor/verify-otp | POST | Validate email OTP | | /two-factor/generate-backup-codes | POST | Create recovery codes | | /two-factor/verify-backup-code | POST | Use backup code for login | | /two-factor/view-backup-codes | GET | View current backup codes |

📚 Docs: https://www.better-auth.com/docs/plugins/2fa

##### Organization Plugin (Multi-Tenant SaaS)

import { organization } from "better-auth/plugins";

Organizations (10 endpoints):

| Endpoint | Method | Description | |----------|--------|-------------| | /organization/create | POST | Create organization | | /organization/list | GET | List user's organizations | | /organization/get-full | GET | Get complete org details | | /organization/update | PUT | Modify organization | | /organization/delete | DELETE | Remove organization | | /organization/check-slug | GET | Verify slug availability | | /organization/set-active | POST | Set active organization context |

Members (8 endpoints):

| Endpoint | Method | Description | |----------|--------|-------------| | /organization/list-members | GET | Get organization members | | /organization/add-member | POST | Add member directly | | /organization/remove-member | DELETE | Remove member | | /organization/update-member-role | PUT | Change member role | | /organization/get-active-member | GET | Get current member info | | /organization/leave | POST | Leave organization |

Invitations (7 endpoints):

| Endpoint | Method | Description | |----------|--------|-------------| | /organization/invite-member | POST | Send invitation email | | /organization/accept-invitation | POST | Accept invite | | /organization/reject-invitation | POST | Reject invite | | /organization/cancel-invitation | POST | Cancel pending invite | | /organization/get-invitation | GET | Get invitation details | | /organization/list-invitations | GET | List org invitations | | /organization/list-user-invitations | GET | List user's pending invites |

Teams (8 endpoints):

| Endpoint | Method | Description | |----------|--------|-------------| | /organization/create-team | POST | Create team within org | | /organization/list-teams | GET | List organization teams | | /organization/update-team | PUT | Modify team | | /organization/remove-team | DELETE | Remove team | | /organization/set-active-team | POST | Set active team context | | /organization/list-team-members | GET | List team members | | /organization/add-team-member | POST | Add member to team | | /organization/remove-team-member | DELETE | Remove team member |

Permissions & Roles (6 endpoints):

| Endpoint | Method | Description | |----------|--------|-------------| | /organization/has-permission | POST | Check if user has permission | | /organization/create-role | POST | Create custom role | | /organization/delete-role | DELETE | Delete custom role | | /organization/list-roles | GET | List all roles | | /organization/get-role | GET | Get role details | | /organization/update-role | PUT | Modify role permissions |

📚 Docs: https://www.better-auth.com/docs/plugins/organization

##### Admin Plugin

import { admin } from "better-auth/plugins";
// v1.4.10 configuration options
admin({
  defaultRole: "user",
  adminRoles: ["admin"],
  adminUserIds: ["user_abc123"], // Always grant admin to specific users
  impersonationSessionDuration: 3600, // 1 hour (seconds)
  allowImpersonatingAdmins: false, // ⚠️ Default changed in v1.4.6
  defaultBanReason: "Violation of Terms of Service",
  bannedUserMessage: "Your account has been suspended",
})

| Endpoint | Method | Description | |----------|--------|-------------| | /admin/create-user | POST | Create user as admin | | /admin/list-users | GET | List all users (with filters/pagination) | | /admin/set-role | POST | Assign user role | | /admin/set-user-password | POST | Change user password | | /admin/update-user | PUT | Modify user details | | /admin/remove-user | DELETE | Delete user account | | /admin/ban-user | POST | Ban user account (with optional expiry) | | /admin/unban-user | POST | Unban user | | /admin/list-user-sessions | GET | Get user's active sessions | | /admin/revoke-user-session | DELETE | End specific user session | | /admin/revoke-user-sessions | DELETE | End all user sessions | | /admin/impersonate-user | POST | Start impersonating user | | /admin/stop-impersonating | POST | End impersonation session |

⚠️ Breaking Change (v1.4.6): allowImpersonatingAdmins now defaults to false. Set to true explicitly if you need admin-on-admin impersonation.

Custom Roles with Permissions (v1.4.10):

import { createAccessControl } from "better-auth/plugins/access";
// Define resources and permissions
const ac = createAccessControl({
  user: ["create", "read", "update", "delete", "ban", "impersonate"],
  project: ["create", "read", "update", "delete", "share"],
} as const);
// Create custom roles
const supportRole = ac.newRole({
  user: ["read", "ban"],      // Can view and ban users
  project: ["read"],          // Can view projects
});
const managerRole = ac.newRole({
  user: ["read", "update"],
  project: ["create", "read", "update", "delete"],
});
// Use in plugin
admin({
  ac,
  roles: {
    support: supportRole,
    manager: managerRole,
  },
})

📚 Docs: https://www.better-auth.com/docs/plugins/admin

##### Other Plugin Endpoints

Passkey Plugin (5 endpoints) - Docs:

/passkey/add, /sign-in/passkey, /passkey/list, /passkey/delete, /passkey/update

Magic Link Plugin (2 endpoints) - Docs:

/sign-in/magic-link, /magic-link/verify

Username Plugin (2 endpoints) - Docs:

/sign-in/username, /username/is-available

Phone Number Plugin (5 endpoints) - Docs:

/sign-in/phone-number, /phone-number/send-otp, /phone-number/verify, /phone-number/request-password-reset, /phone-number/reset-password

Email OTP Plugin (6 endpoints) - Docs:

/email-otp/send-verification-otp, /email-otp/check-verification-otp, /sign-in/email-otp, /email-otp/verify-email, /forget-password/email-otp, /email-otp/reset-password

Anonymous Plugin (1 endpoint) - Docs:

/sign-in/anonymous

JWT Plugin (2 endpoints) - Docs:

/token (get JWT), /jwks (public key for verification)

OpenAPI Plugin (2 endpoints) - Docs:

/reference (interactive API docs with Scalar UI)

/generate-openapi-schema (get OpenAPI spec as JSON)

---

Server-Side API Methods (auth.api.*)

Every HTTP endpoint has a corresponding server-side method. Use these for:

Server-side middleware (protecting routes)

Background jobs (user cleanup, notifications)

Admin operations (bulk user management)

Custom auth flows (programmatic session creation)

#### Core API Methods

// Authentication
await auth.api.signUpEmail({
  body: { email, password, name },
  headers: request.headers,
});
await auth.api.signInEmail({
  body: { email, password, rememberMe: true },
  headers: request.headers,
});
await auth.api.signOut({ headers: request.headers });
// Session Management
const session = await auth.api.getSession({ headers: request.headers });
await auth.api.listSessions({ headers: request.headers });
await auth.api.revokeSession({
  body: { token: "session_token_here" },
  headers: request.headers,
});
// User Management
await auth.api.updateUser({
  body: { name: "New Name", image: "https://..." },
  headers: request.headers,
});
await auth.api.changeEmail({
  body: { newEmail: "newemail@example.com" },
  headers: request.headers,
});
await auth.api.deleteUser({
  body: { password: "current_password" },
  headers: request.headers,
});
// Account Linking
await auth.api.linkSocialAccount({
  body: { provider: "google" },
  headers: request.headers,
});
await auth.api.unlinkAccount({
  body: { providerId: "google", accountId: "google_123" },
  headers: request.headers,
});

#### Plugin API Methods

2FA Plugin:

// Enable 2FA
const { totpUri, backupCodes } = await auth.api.enableTwoFactor({
  body: { issuer: "MyApp" },
  headers: request.headers,
});
// Verify TOTP code
await auth.api.verifyTOTP({
  body: { code: "123456", trustDevice: true },
  headers: request.headers,
});
// Generate backup codes
const { backupCodes } = await auth.api.generateBackupCodes({
  headers: request.headers,
});

Organization Plugin:

// Create organization
const org = await auth.api.createOrganization({
  body: { name: "Acme Corp", slug: "acme" },
  headers: request.headers,
});
// Add member
await auth.api.addMember({
  body: {
    userId: "user_123",
    role: "admin",
    organizationId: org.id,
  },
  headers: request.headers,
});
// Check permissions
const hasPermission = await auth.api.hasPermission({
  body: {
    organizationId: org.id,
    permission: "users:delete",
  },
  headers: request.headers,
});

Admin Plugin:

// List users with pagination
const users = await auth.api.listUsers({
  query: {
    search: "john",
    limit: 10,
    offset: 0,
    sortBy: "createdAt",
    sortOrder: "desc",
  },
  headers: request.headers,
});
// Ban user
await auth.api.banUser({
  body: {
    userId: "user_123",
    reason: "Violation of ToS",
    expiresAt: new Date("2025-12-31"),
  },
  headers: request.headers,
});
// Impersonate user (for admin support)
const impersonationSession = await auth.api.impersonateUser({
  body: {
    userId: "user_123",
    expiresIn: 3600, // 1 hour
  },
  headers: request.headers,
});

---

When to Use Which

| Use Case | Use HTTP Endpoints | Use auth.api.* Methods | |----------|-------------------|--------------------------| | Client-side auth | ✅ Yes | ❌ No | | Server middleware | ❌ No | ✅ Yes | | Background jobs | ❌ No | ✅ Yes | | Admin dashboards | ✅ Yes (from client) | ✅ Yes (from server) | | Custom auth flows | ❌ No | ✅ Yes | | Mobile apps | ✅ Yes | ❌ No | | API routes | ✅ Yes (proxy to handler) | ✅ Yes (direct calls) |

Example: Protected Route Middleware

import { Hono } from "hono";
import { createAuth } from "./auth";
import { createDatabase } from "./db";
const app = new Hono<{ Bindings: Env }>();
// Middleware using server-side API
app.use("/api/protected/*", async (c, next) => {
  const db = createDatabase(c.env.DB);
  const auth = createAuth(db, c.env);
  // Use server-side method
  const session = await auth.api.getSession({
    headers: c.req.raw.headers,
  });
  if (!session) {
    return c.json({ error: "Unauthorized" }, 401);
  }
  // Attach to context
  c.set("user", session.user);
  c.set("session", session.session);
  await next();
});
// Protected route
app.get("/api/protected/profile", async (c) => {
  const user = c.get("user");
  return c.json({ user });
});

---

Discovering Available Endpoints

Use the OpenAPI plugin to see all endpoints in your configuration:

import { betterAuth } from "better-auth";
import { openAPI } from "better-auth/plugins";
export const auth = betterAuth({
  database: /* ... */,
  plugins: [
    openAPI(), // Adds /api/auth/reference endpoint
  ],
});

Interactive documentation: Visit http://localhost:8787/api/auth/reference

This shows a Scalar UI with:

✅ All available endpoints grouped by feature

✅ Request/response schemas with types

✅ Try-it-out functionality (test endpoints in browser)

✅ Authentication requirements

✅ Code examples in multiple languages

Programmatic access:

const schema = await auth.api.generateOpenAPISchema();
console.log(JSON.stringify(schema, null, 2));
// Returns full OpenAPI 3.0 spec

---

Quantified Time Savings

Building from scratch (manual implementation):

Core auth endpoints (sign-up, sign-in, OAuth, sessions): 40 hours

Email verification & password reset: 10 hours

2FA system (TOTP, backup codes, email OTP): 20 hours

Organizations (teams, invitations, RBAC): 60 hours

Admin panel (user management, impersonation): 30 hours

Testing & debugging: 50 hours

Security hardening: 20 hours

Total manual effort: ~220 hours (5.5 weeks full-time)

With better-auth:

Initial setup: 2-4 hours

Customization & styling: 2-4 hours

Total with better-auth: 4-8 hours

Savings: ~97% development time

---

Key Takeaway

better-auth provides 80+ production-ready endpoints covering:

✅ Core authentication (20 endpoints)

✅ 2FA & passwordless (15 endpoints)

✅ Organizations & teams (35 endpoints)

✅ Admin & user management (15 endpoints)

✅ Social OAuth (auto-configured callbacks)

✅ OpenAPI documentation (interactive UI)

You write zero endpoint code. Just configure features and call auth.handler().

---

Known Issues & Solutions

Issue 1: "d1Adapter is not exported" Error

Problem: Code shows import { d1Adapter } from 'better-auth/adapters/d1' but this doesn't exist.

Symptoms: TypeScript error or runtime error about missing export.

Solution: Use Drizzle or Kysely instead:

// ❌ WRONG - This doesn't exist
import { d1Adapter } from 'better-auth/adapters/d1'
database: d1Adapter(env.DB)
// ✅ CORRECT - Use Drizzle
import { drizzleAdapter } from 'better-auth/adapters/drizzle'
import { drizzle } from 'drizzle-orm/d1'
const db = drizzle(env.DB, { schema })
database: drizzleAdapter(db, { provider: "sqlite" })
// ✅ CORRECT - Use Kysely
import { Kysely } from 'kysely'
import { D1Dialect } from 'kysely-d1'
database: {
  db: new Kysely({ dialect: new D1Dialect({ database: env.DB }) }),
  type: "sqlite"
}

Source: Verified from 4 production repositories using better-auth + D1

---

Issue 2: Schema Generation Fails

Problem: npx better-auth migrate doesn't create D1-compatible schema.

Symptoms: Migration SQL has wrong syntax or doesn't work with D1.

Solution: Use Drizzle Kit to generate migrations:

# Generate migration from Drizzle schema
npx drizzle-kit generate
Apply to D1
wrangler d1 migrations apply my-app-db --remote

Why: Drizzle Kit generates SQLite-compatible SQL that works with D1.

---

Issue 3: "CamelCase" vs "snake_case" Column Mismatch

Problem: Database has email_verified but better-auth expects emailVerified.

Symptoms: Session reads fail, user data missing fields.

⚠️ CRITICAL (v1.4.10+): Using Kysely's CamelCasePlugin breaks join parsing in better-auth adapter. The plugin converts join keys like _joined_user_user_id to _joinedUserUserId, causing user data to be null in session queries.

Solution for Drizzle: Define schema with camelCase from the start (as shown in examples).

Solution for Kysely with CamelCasePlugin: Use separate Kysely instance without CamelCasePlugin for better-auth:

// DB for better-auth (no CamelCasePlugin)
const authDb = new Kysely({
  dialect: new D1Dialect({ database: env.DB }),
})
// DB for app queries (with CamelCasePlugin)
const appDb = new Kysely({
  dialect: new D1Dialect({ database: env.DB }),
  plugins: [new CamelCasePlugin()],
})
export const auth = betterAuth({
  database: { db: authDb, type: "sqlite" },
})

Source: GitHub Issue #7136

---

Issue 4: D1 Eventual Consistency

Problem: Session reads immediately after write return stale data.

Symptoms: User logs in but getSession() returns null on next request.

Solution: Use Cloudflare KV for session storage (strong consistency):

import { betterAuth } from "better-auth";
export function createAuth(db: Database, env: Env) {
  return betterAuth({
    database: drizzleAdapter(db, { provider: "sqlite" }),
    session: {
      storage: {
        get: async (sessionId) => {
          const session = await env.SESSIONS_KV.get(sessionId);
          return session ? JSON.parse(session) : null;
        },
        set: async (sessionId, session, ttl) => {
          await env.SESSIONS_KV.put(sessionId, JSON.stringify(session), {
            expirationTtl: ttl,
          });
        },
        delete: async (sessionId) => {
          await env.SESSIONS_KV.delete(sessionId);
        },
      },
    },
  });
}

Add to wrangler.toml:

[[kv_namespaces]]
binding = "SESSIONS_KV"
id = "your-kv-namespace-id"

---

Issue 5: CORS Errors for SPA Applications

Problem: CORS errors when auth API is on different origin than frontend.

Symptoms: Access-Control-Allow-Origin errors in browser console.

Solution: Configure CORS headers in Worker and ensure trustedOrigins match:

import { cors } from "hono/cors";
// CRITICAL: Both must match frontend origin exactly
app.use(
  "/api/auth/*",
  cors({
    origin: "http://localhost:5173", // Frontend URL (no trailing slash)
    credentials: true, // Allow cookies
    allowMethods: ["GET", "POST", "PUT", "DELETE", "OPTIONS"],
  })
);
// And in better-auth config
export const auth = betterAuth({
  trustedOrigins: ["http://localhost:5173"], // Same as CORS origin
  // ...
});

Common Mistakes:

Typo in origin URL (trailing slash, http vs https, wrong port)

Mismatched origins between CORS config and trustedOrigins

CORS middleware registered AFTER auth routes (must be before)

Source: GitHub Issue #7434

---

Issue 6: OAuth Redirect URI Mismatch

Problem: Social sign-in fails with "redirect_uri_mismatch" error.

Symptoms: Google/GitHub OAuth returns error after user consent.

Solution: Ensure exact match in OAuth provider settings:

Provider setting: https://yourdomain.com/api/auth/callback/google
better-auth URL:  https://yourdomain.com/api/auth/callback/google
❌ Wrong: http vs https, trailing slash, subdomain mismatch
✅ Right: Exact character-for-character match

Check better-auth callback URL:

// It's always: {baseURL}/api/auth/callback/{provider}
const callbackURL = ${env.BETTER_AUTH_URL}/api/auth/callback/google;
console.log("Configure this URL in Google Console:", callbackURL);

---

Issue 7: Missing Dependencies

Problem: TypeScript errors or runtime errors about missing packages.

Symptoms: Cannot find module 'drizzle-orm' or similar.

Solution: Install all required packages:

For Drizzle approach:

npm install better-auth drizzle-orm drizzle-kit @cloudflare/workers-types

For Kysely approach:

npm install better-auth kysely kysely-d1 @cloudflare/workers-types

---

Issue 8: Email Verification Not Sending

Problem: Email verification links never arrive.

Symptoms: User signs up, but no email received.

Solution: Implement sendVerificationEmail handler:

export const auth = betterAuth({
  database: /* ... */,
  emailAndPassword: {
    enabled: true,
    requireEmailVerification: true,
  },
  emailVerification: {
    sendVerificationEmail: async ({ user, url }) => {
      // Use your email service (SendGrid, Resend, etc.)
      await sendEmail({
        to: user.email,
        subject: "Verify your email",
        html: 
          
Click the link below to verify your email:
          Verify Email
        ,
      });
    },
    sendOnSignUp: true,
    autoSignInAfterVerification: true,
    expiresIn: 3600, // 1 hour
  },
});

For Cloudflare: Use Cloudflare Email Routing or external service (Resend, SendGrid).

---

Issue 9: Session Expires Too Quickly

Problem: Session expires unexpectedly or never expires.

Symptoms: User logged out unexpectedly or session persists after logout.

Solution: Configure session expiration:

export const auth = betterAuth({
  database: /* ... */,
  session: {
    expiresIn: 60 * 60 * 24 * 7, // 7 days (in seconds)
    updateAge: 60 * 60 * 24, // Update session every 24 hours
  },
});

---

Issue 10: Social Provider Missing User Data

Problem: Social sign-in succeeds but missing user data (name, avatar).

Symptoms: session.user.name is null after Google/GitHub sign-in.

Solution: Request additional scopes:

socialProviders: {
  google: {
    clientId: env.GOOGLE_CLIENT_ID,
    clientSecret: env.GOOGLE_CLIENT_SECRET,
    scope: ["openid", "email", "profile"], // Include 'profile' for name/image
  },
  github: {
    clientId: env.GITHUB_CLIENT_ID,
    clientSecret: env.GITHUB_CLIENT_SECRET,
    scope: ["user:email", "read:user"], // 'read:user' for full profile
  },
}

---

Issue 11: TypeScript Errors with Drizzle Schema

Problem: TypeScript complains about schema types.

Symptoms: Type 'DrizzleD1Database' is not assignable to...

Solution: Export proper types from database:

// src/db/index.ts
import { drizzle, type DrizzleD1Database } from "drizzle-orm/d1";
import * as schema from "./schema";
export type Database = DrizzleD1Database;
export function createDatabase(d1: D1Database): Database {
  return drizzle(d1, { schema });
}

---

Issue 12: Wrangler Dev Mode Not Working

Problem: wrangler dev fails with database errors.

Symptoms: "Database not found" or migration errors in local dev.

Solution: Apply migrations locally first:

# Apply migrations to local D1
wrangler d1 migrations apply my-app-db --local
Then run dev server
wrangler dev

---

Issue 13: User Data Updates Not Reflecting in UI (with TanStack Query)

Problem: After updating user data (e.g., avatar, name), changes don't appear in useSession() despite calling queryClient.invalidateQueries().

Symptoms: Avatar image or user profile data appears stale after successful update. TanStack Query cache shows updated data, but better-auth session still shows old values.

Root Cause: better-auth uses nanostores for session state management, not TanStack Query. Calling queryClient.invalidateQueries() only invalidates React Query cache, not the better-auth nanostore.

Solution: Manually notify the nanostore after updating user data:

// Update user data
const { data, error } = await authClient.updateUser({
  image: newAvatarUrl,
  name: newName
})
if (!error) {
  // Manually invalidate better-auth session state
  authClient.$store.notify('$sessionSignal')
  // Optional: Also invalidate React Query if using it for other data
  queryClient.invalidateQueries({ queryKey: ['user-profile'] })
}

When to use:

Using better-auth + TanStack Query together

Updating user profile fields (name, image, email)

Any operation that modifies session user data client-side

Alternative: Call refetch() from useSession(), but $store.notify() is more direct:

const { data: session, refetch } = authClient.useSession()
// After update
await refetch()

Note: $store is an undocumented internal API. This pattern is production-validated but may change in future better-auth versions.

Source: Community-discovered pattern, production use verified

---

Issue 14: apiKey Table Schema Mismatch with D1

Problem: better-auth CLI (npx @better-auth/cli generate) fails with "Failed to initialize database adapter" when using D1.

Symptoms: CLI cannot connect to D1 to introspect schema. Running migrations through CLI doesn't work.

Root Cause: The CLI expects a direct SQLite connection, but D1 requires Cloudflare's binding API.

Solution: Skip the CLI and create migrations manually using the documented apiKey schema:

CREATE TABLE api_key (
  id TEXT PRIMARY KEY NOT NULL,
  user_id TEXT NOT NULL REFERENCES user(id) ON DELETE CASCADE,
  name TEXT,
  start TEXT,
  prefix TEXT,
  key TEXT NOT NULL,
  enabled INTEGER DEFAULT 1,
  rate_limit_enabled INTEGER,
  rate_limit_time_window INTEGER,
  rate_limit_max INTEGER,
  request_count INTEGER DEFAULT 0,
  last_request INTEGER,
  remaining INTEGER,
  refill_interval INTEGER,
  refill_amount INTEGER,
  last_refill_at INTEGER,
  expires_at INTEGER,
  permissions TEXT,
  metadata TEXT,
  created_at INTEGER NOT NULL,
  updated_at INTEGER NOT NULL
);

Key Points:

The table has exactly 21 columns (as of better-auth v1.4+)

Column names use snake_case (e.g., rate_limit_time_window, not rateLimitTimeWindow)

D1 doesn't support ALTER TABLE DROP COLUMN - if schema drifts, use fresh migration pattern (drop and recreate tables)

In Drizzle adapter config, use apikey (lowercase) as the table name mapping

Fresh Migration Pattern for D1:

-- Drop in reverse dependency order
DROP TABLE IF EXISTS api_key;
DROP TABLE IF EXISTS session;
-- ... other tables
-- Recreate with clean schema
CREATE TABLE api_key (...);

Source: Production debugging with D1 + better-auth apiKey plugin

---

Issue 15: Admin Plugin Requires DB Role (Dual-Auth)

Problem: Admin plugin methods like listUsers fail with "You are not allowed to list users" even though your middleware passes.

Symptoms: Custom requireAdmin middleware (checking ADMIN_EMAILS env var) passes, but auth.api.listUsers() returns 403.

Root Cause: better-auth admin plugin has two authorization layers: 1. Your middleware - Custom check (e.g., ADMIN_EMAILS) 2. better-auth internal - Checks user.role === 'admin' in database

Both must pass for admin plugin methods to work.

Solution: Set user role to 'admin' in the database:

-- Fix for existing users
UPDATE user SET role = 'admin' WHERE email = 'admin@example.com';

Or use the admin UI/API to set roles after initial setup.

Why: The admin plugin's listUsers, banUser, impersonateUser, etc. all check user.role in the database, not your custom middleware logic.

Source: Production debugging - misleading error message led to root cause discovery via wrangler tail

---

Issue 16: Organization/Team updated_at Must Be Nullable

Problem: Organization creation fails with SQL constraint error even though API returns "slug already exists".

Symptoms:

Error message says "An organization with this slug already exists"

Database table is actually empty

wrangler tail shows: Failed query: insert into "organization" ... values (?, ?, ?, null, null, ?, null)

Root Cause: better-auth inserts null for updated_at on creation (only sets it on updates). If your schema has NOT NULL constraint, insert fails.

Solution: Make updated_at nullable in both schema and migrations:

// Drizzle schema - CORRECT
export const organization = sqliteTable('organization', {
  // ...
  updatedAt: integer('updated_at', { mode: 'timestamp' }), // No .notNull()
});
export const team = sqliteTable('team', {
  // ...
  updatedAt: integer('updated_at', { mode: 'timestamp' }), // No .notNull()
});

-- Migration - CORRECT
CREATE TABLE organization (
  -- ...
  updated_at INTEGER  -- No NOT NULL
);

Applies to: organization and team tables (possibly other plugin tables)

Source: Production debugging - wrangler tail revealed actual SQL error behind misleading "slug exists" message

---

Issue 17: API Response Double-Nesting (listMembers, etc.)

Problem: Custom API endpoints return double-nested data like { members: { members: [...], total: N } }.

Symptoms: UI shows "undefined" for counts, empty lists despite data existing.

Root Cause: better-auth methods like listMembers return { members: [...], total: N }. Wrapping with c.json({ members: result }) creates double nesting.

Solution: Extract the array from better-auth response:

// ❌ WRONG - Double nesting
const result = await auth.api.listMembers({ ... });
return c.json({ members: result });
// Returns: { members: { members: [...], total: N } }
// ✅ CORRECT - Extract array
const result = await auth.api.listMembers({ ... });
const members = result?.members || [];
return c.json({ members });
// Returns: { members: [...] }

Affected methods (return objects, not arrays):

listMembers → { members: [...], total: N }

listUsers → { users: [...], total: N, limit: N }

listOrganizations → { organizations: [...] } (check structure)

listInvitations → { invitations: [...] }

Pattern: Always check better-auth method return types before wrapping in your API response.

Source: Production debugging - UI showed "undefined" count, API inspection revealed nesting issue

---

Issue 18: Expo Client fromJSONSchema Crash (v1.4.16)

Problem: Importing expoClient from @better-auth/expo/client crashes with TypeError: Cannot read property 'fromJSONSchema' of undefined on v1.4.16.

Symptoms: Runtime crash immediately when importing expoClient in React Native/Expo apps.

Root Cause: Regression introduced after PR #6933 (cookie-based OAuth state fix for Expo). One of 3 commits after f4a9f15 broke the build.

Solution:

Temporary: Use continuous build at commit f4a9f15 (pre-regression)

Permanent: Wait for fix (issue #7491 open as of 2026-01-20)

// Crashes on v1.4.16
import { expoClient } from '@better-auth/expo/client'
// Workaround: Use continuous build at f4a9f15
// Or wait for fix in next release

Source: GitHub Issue #7491

---

Issue 19: additionalFields string[] Returns Stringified JSON

Problem: After v1.4.12, additionalFields with type: 'string[]' return stringified arrays ('["a","b"]') instead of native arrays when querying via Drizzle directly.

Symptoms: user.notificationTokens is a string, not an array. Code expecting arrays breaks.

Root Cause: In Drizzle adapter, string[] fields are stored with mode: 'json', which expects arrays. But better-auth v1.4.4+ passes strings to Drizzle, causing double-stringification. When querying directly via Drizzle, the value is a string, but when using better-auth internalAdapter, a transformer correctly returns an array.

Solution: 1. Use better-auth internalAdapter instead of querying Drizzle directly (has transformer) 2. Change Drizzle schema to .jsonb() for string[] fields 3. Manually parse JSON strings until fixed

// Config
additionalFields: {
  notificationTokens: {
    type: 'string[]',
    required: true,
    input: true,
  },
}
// Create user
notificationTokens: ['token1', 'token2']
// Result in DB (when querying via Drizzle directly)
// '["token1","token2"]' (string, not array)

Source: GitHub Issue #7440

---

Issue 20: additionalFields "returned" Property Blocks Input

Problem: Setting returned: false on additionalFields prevents field from being saved via API, even with input: true.

Symptoms: Field never saved to database when creating/updating via API endpoints.

Root Cause: The returned: false property blocks both read AND write operations, not just reads as intended. The input: true property should control write access independently.

Solution:

Don't use returned: false if you need API write access

Write via server-side methods (auth.api.*) instead

// Organization plugin config
additionalFields: {
  secretField: {
    type: 'string',
    required: true,
    input: true,      // Should allow API writes
    returned: false,  // Should only block reads, but blocks writes too
  },
}
// API request to create organization
// secretField is never saved to database

Source: GitHub Issue #7489

---

Issue 21: freshAge Based on Creation Time, Not Activity

Problem: session.freshAge checks time-since-creation, NOT recent activity. Active sessions become "not fresh" after freshAge elapses, even if used constantly.

Symptoms: "Fresh session required" endpoints reject valid active sessions.

Why It Happens: The freshSessionMiddleware checks Date.now() - (session.updatedAt || session.createdAt), but updatedAt only changes when the session is refreshed based on updateAge. If updateAge > freshAge, the session becomes "not fresh" before updatedAt is bumped.

Solution: 1. Set updateAge <= freshAge to ensure freshness is updated before expiry 2. Avoid "fresh session required" gating for long-lived sessions 3. Accept as design: freshAge is strictly time-since-creation (maintainer confirmed)

// Config
session: {
  expiresIn: 60 * 60 * 24 * 7,    // 7 days
  freshAge: 60 * 60 * 24,          // 24 hours
  updateAge: 60 * 60 * 24 * 3,     // 3 days (> freshAge!) ⚠️ PROBLEM
  // CORRECT - updateAge <= freshAge
  updateAge: 60 * 60 * 12,         // 12 hours (< freshAge)
}
// Timeline with bad config:
// T+0h: User signs in (createdAt = now)
// T+12h: User makes requests (session active, still fresh)
// T+25h: User makes request (session active, BUT NOT FRESH - freshAge elapsed)
// Result: "Fresh session required" endpoints reject active session

Source: GitHub Issue #7472

---

Issue 22: OAuth Token Endpoints Return Wrapped JSON

Problem: OAuth 2.1 and OIDC token endpoints return { "response": { ...tokens... } } instead of spec-compliant top-level JSON. OAuth clients expect { "access_token": "...", "token_type": "bearer" } at root.

Symptoms: OAuth clients fail with Bearer undefined or invalid_token.

Root Cause: The endpoint pipeline returns { response, headers, status } for internal use, which gets serialized directly for HTTP requests. This breaks OAuth/OIDC spec requirements.

Solution:

Temporary: Manually unwrap .response field on client

Permanent: Wait for fix (issue #7355 open, accepting contributions)

// Expected (spec-compliant)
{ "access_token": "...", "token_type": "bearer", "expires_in": 3600 }
// Actual (wrapped)
{ "response": { "access_token": "...", "token_type": "bearer", "expires_in": 3600 } }
// Result: OAuth clients fail to parse, send Bearer undefined

Source: GitHub Issue #7355

---

Migration Guides

From Clerk

Key differences:

Clerk: Third-party service → better-auth: Self-hosted

Clerk: Proprietary → better-auth: Open source

Clerk: Monthly cost → better-auth: Free

Migration steps:

1. Export user data from Clerk (CSV or API) 2. Import into better-auth database:

   // migration script
   const clerkUsers = await fetchClerkUsers();
   for (const clerkUser of clerkUsers) {
     await db.insert(user).values({
       id: clerkUser.id,
       email: clerkUser.email,
       emailVerified: clerkUser.email_verified,
       name: clerkUser.first_name + " " + clerkUser.last_name,
       image: clerkUser.profile_image_url,
     });
   }
   

3. Replace Clerk SDK with better-auth client:

   // Before (Clerk)
   import { useUser } from "@clerk/nextjs";
   const { user } = useUser();
   // After (better-auth)
   import { authClient } from "@/lib/auth-client";
   const { data: session } = authClient.useSession();
   const user = session?.user;
   

4. Update middleware for session verification 5. Configure social providers (same OAuth apps, different config)

---

From Auth.js (NextAuth)

Key differences:

Auth.js: Limited features → better-auth: Comprehensive (2FA, orgs, etc.)

Auth.js: Callbacks-heavy → better-auth: Plugin-based

Auth.js: Session handling varies → better-auth: Consistent

Migration steps:

1. Database schema: Auth.js and better-auth use similar schemas, but column names differ 2. Replace configuration:

   // Before (Auth.js)
   import NextAuth from "next-auth";
   import GoogleProvider from "next-auth/providers/google";
   export default NextAuth({
     providers: [GoogleProvider({ /* ... */ })],
   });
   // After (better-auth)
   import { betterAuth } from "better-auth";
   export const auth = betterAuth({
     socialProviders: {
       google: { /* ... */ },
     },
   });
   

3. Update client hooks:

   // Before
   import { useSession } from "next-auth/react";
   // After
   import { authClient } from "@/lib/auth-client";
   const { data: session } = authClient.useSession();
   

---

Additional Resources

Official Documentation

Homepage: https://better-auth.com

Introduction: https://www.better-auth.com/docs/introduction

Installation: https://www.better-auth.com/docs/installation

Basic Usage: https://www.better-auth.com/docs/basic-usage

Core Concepts

Session Management: https://www.better-auth.com/docs/concepts/session-management

Users & Accounts: https://www.better-auth.com/docs/concepts/users-accounts

Client SDK: https://www.better-auth.com/docs/concepts/client

Plugins System: https://www.better-auth.com/docs/concepts/plugins

Authentication Methods

Email & Password: https://www.better-auth.com/docs/authentication/email-password

OAuth Providers: https://www.better-auth.com/docs/concepts/oauth

Plugin Documentation

Core Plugins:

2FA (Two-Factor): https://www.better-auth.com/docs/plugins/2fa

Organization: https://www.better-auth.com/docs/plugins/organization

Admin: https://www.better-auth.com/docs/plugins/admin

Multi-Session: https://www.better-auth.com/docs/plugins/multi-session

API Key: https://www.better-auth.com/docs/plugins/api-key

Generic OAuth: https://www.better-auth.com/docs/plugins/generic-oauth

Passwordless Plugins:

Passkey: https://www.better-auth.com/docs/plugins/passkey

Magic Link: https://www.better-auth.com/docs/plugins/magic-link

Email OTP: https://www.better-auth.com/docs/plugins/email-otp

Phone Number: https://www.better-auth.com/docs/plugins/phone-number

Anonymous: https://www.better-auth.com/docs/plugins/anonymous

Advanced Plugins:

Username: https://www.better-auth.com/docs/plugins/username

JWT: https://www.better-auth.com/docs/plugins/jwt

OpenAPI: https://www.better-auth.com/docs/plugins/open-api

OIDC Provider: https://www.better-auth.com/docs/plugins/oidc-provider

SSO: https://www.better-auth.com/docs/plugins/sso

Stripe: https://www.better-auth.com/docs/plugins/stripe

MCP: https://www.better-auth.com/docs/plugins/mcp

Framework Integrations

TanStack Start: https://www.better-auth.com/docs/integrations/tanstack

Expo (React Native): https://www.better-auth.com/docs/integrations/expo

Community & Support

GitHub: https://github.com/better-auth/better-auth (22.4k ⭐)

Examples: https://github.com/better-auth/better-auth/tree/main/examples

Discord: https://discord.gg/better-auth

Changelog: https://github.com/better-auth/better-auth/releases

Related Documentation

Drizzle ORM: https://orm.drizzle.team/docs/get-started-sqlite

Kysely: https://kysely.dev/

---

Production Examples

Verified working D1 repositories (all use Drizzle or Kysely):

1. zpg6/better-auth-cloudflare - Drizzle + D1 (includes CLI) 2. zwily/example-react-router-cloudflare-d1-drizzle-better-auth - Drizzle + D1 3. foxlau/react-router-v7-better-auth - Drizzle + D1 4. matthewlynch/better-auth-react-router-cloudflare-d1 - Kysely + D1

None use a direct d1Adapter - all require Drizzle/Kysely.

---

Version Compatibility

Tested with:

better-auth@1.4.10

drizzle-orm@0.45.1

drizzle-kit@0.31.8

kysely@0.28.9

kysely-d1@0.4.0

@cloudflare/workers-types@latest

hono@4.11.3

Node.js 18+, Bun 1.0+

Breaking changes:

v1.4.6: allowImpersonatingAdmins defaults to false

v1.4.0: ESM-only (no CommonJS)

v1.3.0: Multi-team table structure change

Check changelog: https://github.com/better-auth/better-auth/releases

---

Community Resources

Cloudflare-specific guides:

zpg6/better-auth-cloudflare - Drizzle + D1 reference

Hono + better-auth on Cloudflare - Official Hono example

React Router + Cloudflare D1 - React Router v7 guide

SvelteKit + Cloudflare D1 - SvelteKit guide

---

Token Efficiency:

Without skill: ~35,000 tokens (D1 adapter errors, 15+ plugins, rate limiting, session caching, database hooks, mobile integration)

With skill: ~8,000 tokens (focused on errors + patterns + all plugins + API reference)

Savings: ~77% (~27,000 tokens)

Errors prevented: 22 documented issues with exact solutions Key value: D1 adapter requirement, nodejs_compat flag, OAuth 2.1 Provider, Bearer/OneTap/SCIM/Anonymous plugins, rate limiting, session caching, database hooks, Expo integration, 80+ endpoint reference, additionalFields bugs, freshAge behavior, OAuth token wrapping

---

Last verified: 2026-01-21 | Skill version: 5.1.0 | Changes: Added 5 new issues from post-training-cutoff research (Expo fromJSONSchema crash, additionalFields string[] bug, additionalFields returned property bug, freshAge not activity-based, OAuth token wrapping). Expanded Issue #3 with Kysely CamelCasePlugin join parsing failure. Expanded Issue #5 with Hono CORS pattern. Added Cloudflare Workers DB binding constraints note. Added TanStack Start session nullability pattern. Updated to v1.4.16.