A high-performance, event-driven in-memory database designed specifically for frontend applications. OIMDB provides reactive collections, intelligent indexing, and configurable event processing for building fast, predictable state management solutions.

OIMDB is now organized as a monorepo with separate packages:

The foundational reactive collections, indexing, and event processing library.

npm install @oimdb/core

Key Features:

• Reactive collections/objects/indexes with key-scoped subscriptions
• Intelligent event coalescing and reentrancy-safe delivery for optimal performance
• Configurable schedulers (microtask, timeout, animationFrame, immediate)
• Effects & Computed scheduled via OIMComputeRuntime (single draining queue.flush() boundary)
• Type-safe operations with full TypeScript support
• O(1) lookups and efficient indexing

📖 See @oimdb/core documentation

React hooks for seamless integration with OIMDB reactive collections.

npm install @oimdb/react @oimdb/core

Key Features:

• Direct integration with OIMReactiveCollection and collection-bound indexes
• Automatic subscriptions using useSyncExternalStore
• React Context support for centralized collection management
• Key-specific subscriptions for efficient re-renders

📖 See @oimdb/react documentation

Production-ready Redux adapter for gradual migration from Redux to OIMDB or hybrid usage.

npm install @oimdb/redux-adapter @oimdb/core redux

Key Features:

• 🔄 Two-Way Synchronization: Automatic sync between OIMDB and Redux in both directions
• ⚡ Automatic Flushing: Built-in middleware automatically processes events after Redux actions
• 📦 Production Ready: Battle-tested, optimized for large datasets
• 🔄 Gradual Migration: Integrate OIMDB into existing Redux projects without breaking changes
• 🎯 Flexible State Mapping: Custom mappers for any Redux state structure
• ⚡ Performance Optimized: Efficient diffing algorithms and batched updates

Perfect for:

• Migrating from Redux to OIMDB incrementally
• Using OIMDB for complex relational data alongside Redux
• Replacing Redux entirely while maintaining compatibility

📖 See @oimdb/redux-adapter documentation

import { OIMReactiveCollection, OIMEventQueue, OIMEventQueueSchedulerFactory } from '@oimdb/core';

interface User {
  id: string;
  name: string;
  email: string;
}

// Create reactive collection
const queue = new OIMEventQueue({
  scheduler: OIMEventQueueSchedulerFactory.createMicrotask()
});

const users = new OIMReactiveCollection<User, string>(queue, {
  selectPk: (user) => user.id
});

// Subscribe to changes
users.updateEventEmitter.subscribeOnKey('user1', () => {
  console.log('User1 updated!');
});

// Insert and update data. Writes return canonical slots, which can be reused by indexes.
const userSlot = users.upsertOne({
  id: 'user1',
  name: 'John',
  email: 'john@example.com'
});
const updatedUserSlot = users.upsertOne({
  id: 'user1',
  name: 'John Doe',
  email: 'john@example.com'
});
console.log(userSlot === updatedUserSlot); // true
// Only one notification fires due to intelligent coalescing

• 🚀 Performance First: Map-based storage with O(1) lookups
• 📡 Reactive Architecture: Automatic change notifications with intelligent coalescing
• 🔧 Type Safety: Full TypeScript support with advanced generics
• ⚡ Configurable: Multiple scheduler options for different use cases
• 🏗️ Modular: Use only what you need, extend what you want

For detailed documentation and API reference, visit the individual package READMEs:

• @oimdb/core - Complete core library documentation
• @oimdb/react - React integration guide
• @oimdb/redux-adapter - Redux migration and integration guide

# Install dependencies
npm install

# Run tests
npm test

# Run benchmarks
npm run bench

# Build packages
npm run build

Full documentation is published at oimdb.org.

Source docs live in website/docs/.

Contributions are welcome! OIMDB is designed to be modular and extensible.

MIT License - see LICENSE file for details.

• Issues: GitHub Issues

OIMDB - High-performance, reactive in-memory database for frontend applications. 🚀