better_auth-mongo-adapter

MongoDB database adapter package for Better Auth Ruby.

Installation

Add the gem and require the package before configuring auth:

gem "better_auth-mongo-adapter"

require "mongo"
require "better_auth/mongo_adapter"

mongo_client = Mongo::Client.new(ENV.fetch("BETTER_AUTH_MONGODB_URL"))

auth = BetterAuth.auth(
  secret: ENV.fetch("BETTER_AUTH_SECRET"),
  database: BetterAuth::Adapters::MongoDB.new(
    database: mongo_client.database,
    client: mongo_client,
    transaction: false
  )
)

Notes

This package depends on the official mongo gem. Keeping MongoDB support outside better_auth avoids installing MongoDB client dependencies for applications that only use SQL, Rails, Hanami, or in-memory storage.

The adapter stores Better Auth models in singular MongoDB collections by default, maps logical id values to Mongo _id, converts ObjectId-compatible ids through the Mongo driver, and supports the shared Better Auth database adapter contract.