better-auth - D1 Adapter & Error Prevention Guide

Package: better-auth@1.4.0 (Nov 22, 2025) Breaking Changes: ESM-only (v1.4.0), 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 v1.4.0 (Nov 22, 2025)