payloadAdapter
The Better Auth database adapter that stores auth data in Payload collections. Options, ID and database detection, and custom model names.
payloadAdapter(config) creates a Better Auth database adapter that reads and writes Payload collections through the Local API. It is built on Better Auth's createAdapterFactory, so schema-aware transformations (field renames, ID coercion, plugin models) come from Better Auth itself.
import { payloadAdapter } from '@delmaredigital/payload-better-auth'
betterAuth({
database: payloadAdapter({
payloadClient: payload,
adapterConfig: {
enableDebugLogs: false,
atomicWrites: 'auto',
},
}),
})Options
Prop
Type
Detection
- Database. A Payload database adapter whose name contains
mongoormongooseis MongoDB,sqliteis SQLite, and anything else is treated as Postgres. - ID type. MongoDB is always
'text'. Otherwise an explicitidTypewins; then a Better Authadvanced.database.generateIdother than'serial'means'text'; otherwise'number'.
With number IDs, set advanced.database.generateId: 'serial' in Better Auth. Without it, Better Auth's factory doesn't coerce relationship values to numbers, and Payload rejects writes such as user: '1'. The adapter warns when this is missing.
detectDbType(payload) and resolveIdType(dbType, options, explicitIdType?) are exported if you need the same answers elsewhere.
Custom collection names
The adapter uses the standard collection names by default. Set Better Auth's modelName only to change them:
betterAuth({
database: payloadAdapter({ payloadClient: payload }),
user: { modelName: 'member' }, // 'users' → 'members'
session: { modelName: 'auth_session' }, // 'sessions' → 'auth_sessions'
})The adapter runs Better Auth's factory with usePlural: true, matching the default slugs betterAuthCollections() generates.
Atomic operations
Better Auth 1.7 requires consumeOne and incrementOne on every adapter. How this adapter implements them, and the atomicWrites policy, are covered in Atomic operations.