low-json-db

A lightweight, zero-dependency, file-based document database for Node.js.

It stores each collection as a plain JSON file and offers a familiar MongoDB-style API, with indexes, transactions, async support, and more.

Features

• Simple MongoDB-like API (insert, find, update, delete, aggregation)
• Atomic writes for crash safety
• Optional indexes (stored in separate .idx.json files)
• Sync + Async methods
• Transactions
• Auto ID generation (auto-increment, UUID, or ObjectId-style)
• Nested field support
• Import & Backup
• EventEmitter support
• TypeScript declarations included
• Zero dependencies

Installation

npm i low-json-db

Or just copy db.js (and optionally db.d.ts) into your project.

Quick Start

const { JSONDB } = require('low-json-db');
// or
const { JSONDB } = require('./db');

const db = new JSONDB('./data');

const users = db.collection({
  name: 'users',
  autoId: true,
  indexes: ['email']
});

// Insert
const user = users.insert({
  name: 'Alice',
  email: '[email protected]',
  age: 28
});

// Find
const found = users.findOne({ email: '[email protected]' });

// Update
users.updateOne(
  { name: 'Alice' },
  { $set: { age: 29 }, $push: { tags: 'admin' } }
);

// Async example
await users.insertAsync({ name: 'Bob', email: '[email protected]' });

Documentation

Full documentation and examples:
https://amk2406.github.io/low-json-db

License

MIT

Contributing

Feel free to contribute! Open issues or pull requests on the repository.

Happy coding!