@eternasuno/better-auth-acebase

AceBase adapter for better-auth. This package lets you use AceBase as the database for your better-auth instance.

Install

pnpm add @eternasuno/better-auth-acebase acebase

Usage

import { AceBase } from 'acebase';
import { acebaseAdapter } from '@eternasuno/better-auth-acebase';

const db = new AceBase('app', { storage: { path: './data' } });
await db.ready();

export const auth = betterAuth({
  database: acebaseAdapter({ db, usePlural: false }),
  // ... rest of better-auth config
});

Config

| Option | Type | Default | Description | |---------------|-----------|---------|------------------------------------| | db | AceBase | — | The AceBase database instance | | usePlural | boolean | false | Use plural table names | | debugLogs | boolean | false | Enable adapter debug logs |

Development

pnpm install
pnpm build  # tsc -> dist/ (compiled ESM + types)
pnpm test   # runs better-auth adapter test suite
pnpm check      # tsc --noEmit + biome check
pnpm check:fix  # applies Biome fixes

Known limitations

• Null handling: AceBase drops raw null values, so the adapter encodes field-level nulls as the sentinel string __acebase_null__:v2:1fc8c21f5a3f015e455c7379d0c42e6c on write and decodes them back on read. JSON and array fields are declared unsupported so Better Auth serializes them before adapter transforms run, preserving their nested nulls. The random-looking suffix is fixed on purpose, so accidental collisions with real data are practically impossible. The encoding is deliberately idempotent: better-auth's factory applies customTransformInput to where-clause values unconditionally, and stacked adapter factories apply it again — so a value may be encoded more than once. That rules out collision-proof escaping schemes: a stored string exactly equal to the sentinel reads back as null (theoretical risk, accepted and documented).
• Query strategy: filters are translated into AceBase queries. Single OR-group queries push sorting and pagination down to AceBase, while counts use its native count operation. Multiple OR groups run as parallel queries over their complete matching sets, then merge, deduplicate, sort, and paginate in memory. Queries use an explicit TAKE_ALL = Number.MAX_SAFE_INTEGER where needed to avoid AceBase's implicit 100-row limit.
• Case sensitivity: indexes are created with caseSensitive: true, so eq/in/not_in behave case-sensitively by default; better-auth's insensitive mode is implemented via case-insensitive regex matches instead.
• Join limits: join results are capped by better-auth itself — the adapter factory always injects a numeric limit into every join config (defaultFindManyLimit ?? 100, or 1 for one-to-one), regardless of adapter behavior.

License

MIT