Database

Better Auth uses your existing database — no proprietary backend required. It supports PostgreSQL, MySQL, SQLite, and MongoDB through built-in adapters.

Supported Databases

Database	Adapter	ORM Support
PostgreSQL	`postgresql`	Prisma, Drizzle, raw SQL
MySQL	`mysql`	Prisma, Drizzle, raw SQL
SQLite	`sqlite`	Prisma, Drizzle, better-sqlite3
MongoDB	`mongodb`	Mongoose

Configuration

Direct Connection

export const auth = betterAuth({
  database: {
    provider: "postgresql",
    url: process.env.DATABASE_URL,
  },
});

With Prisma

import { PrismaClient } from "@prisma/client";
import { prismaAdapter } from "better-auth/adapters/prisma";

const prisma = new PrismaClient();

export const auth = betterAuth({
  database: prismaAdapter(prisma),
});

With Drizzle

import { drizzle } from "drizzle-orm/node-postgres";
import { drizzleAdapter } from "better-auth/adapters/drizzle";

const db = drizzle(process.env.DATABASE_URL);

export const auth = betterAuth({
  database: drizzleAdapter(db),
});

Schema

Better Auth creates and manages these tables automatically:

`user`

Column	Type	Description
`id`	`string`	Primary key
`name`	`string`	User's display name
`email`	`string`	Unique email address
`emailVerified`	`boolean`	Whether email is verified
`image`	`string?`	Profile image URL
`createdAt`	`datetime`	Account creation timestamp
`updatedAt`	`datetime`	Last update timestamp

`session`

Column	Type	Description
`id`	`string`	Primary key
`userId`	`string`	Foreign key → user
`token`	`string`	Session token (hashed)
`expiresAt`	`datetime`	When the session expires
`ipAddress`	`string?`	Client IP address
`userAgent`	`string?`	Client user agent

`account`

Column	Type	Description
`id`	`string`	Primary key
`userId`	`string`	Foreign key → user
`providerId`	`string`	Auth provider (e.g., "google")
`accountId`	`string`	Provider-specific user ID
`accessToken`	`string?`	OAuth access token
`refreshToken`	`string?`	OAuth refresh token

`verification`

Column	Type	Description
`id`	`string`	Primary key
`identifier`	`string`	What's being verified (email)
`value`	`string`	Verification token
`expiresAt`	`datetime`	Token expiry

Migrations

Automatic Migrations

Better Auth can automatically create and update tables:

npx @better-auth/cli migrate

Generate Migration Files

If you prefer to review migrations before applying:

npx @better-auth/cli generate

This creates SQL files you can review and apply manually.

When using Prisma, run npx @better-auth/cli generate --prisma to generate Prisma schema additions instead of raw SQL.

Custom Fields

You can extend the default schema with custom fields:

export const auth = betterAuth({
  user: {
    additionalFields: {
      role: {
        type: "string",
        defaultValue: "user",
      },
      bio: {
        type: "string",
        required: false,
      },
    },
  },
});

These fields are automatically added to the user table and included in the session user object.

Edit on GitHubllms.txt llms-full.txt