@remelondb/core

@remelondb/core

The platform-independent whole of remelonDB: an offline-first data layer with multi-device sync — reactive SQLite, typed schemas inferred from one definition, and a model-checked sync protocol — rebuilt from WatermelonDB's best ideas on one engine: SQLite everywhere.

This package contains everything except the platform driver: the Q query DSL and its SQL compiler, schema and migrations, the Database/Collection/ Model layer, reactive observation, and the sync engine. It talks to SQLite through a ~7-method SqliteDriver interface; pick the driver for your platform:

Because every driver is real SQLite and passes the same conformance suite (@remelondb/core/conformance), code written against core behaves identically on all of them.

Companions: the @remelondb/core/zod subpath derives tables and sync wire validators from shared Zod schemas; @remelondb/server implements the sync backend over a storage seam, proven by its @remelondb/server/conformance suite.

Example

import {
  appSchema, column as c, table, Database, ModelFor, Q, synchronize,
} from '@remelondb/core'
import { NodeSqliteDriver } from '@remelondb/driver-node'

const tasks = table('tasks', {
  name: c.string(),
  position: c.number().indexed(),
  is_done: c.boolean(),
})

const schema = appSchema({ version: 1, tables: [tasks] })

class Task extends ModelFor(tasks) {
  // no field declarations: name/position/is_done are typed from the
  // table definition; accessors are schema-generated
}

const db = await Database.open({
  driver: new NodeSqliteDriver(),
  schema,
  modelClasses: [Task],
  name: 'app.db',
})

const task = await db.write(() =>
  db.get(Task).create({ name: 'try it', position: 1 }),
)
await db.write(() => task.update(() => { task.is_done = true }))

const unsubscribe = db
  .get(Task)
  .query(Q.where('is_done', false), Q.sortBy('position'))
  .observe((open) => console.log('open tasks:', open.length))

await synchronize({ database: db, pullChanges, pushChanges }) // your backend

Documentation

• Tutorial: a flashcard app's data layer, end to end
• Reference: database & observation · models · queries · sync · schema & migrations · records · the driver contract
• Design: architecture layers · queries as data, one engine · sync protocol

License and credits

MIT. The design owes its best ideas (queries as data, reactive observation, the offline-first sync protocol) to WatermelonDB by Nozbe and contributors (MIT); the code is written from scratch.