Zero Sources

Overview

Zero Sources is a monorepo that hosts various utilities and custom change source implementations designed to integrate with @rocicorp/zero. The primary goal is to provide building blocks and ready-to-use change sources for developers looking to extend or customize Zero's caching and synchronization features.

🚀 Featured: MongoDB Array Unwinding

The MongoDB change source now supports array unwinding in table mappings, enabling you to normalize MongoDB documents with embedded arrays into separate Zero table rows using aggregation pipeline stages.

• ~200x Performance Improvement: Identity-based array diffing generates minimal change events.
• Discriminated Union Architecture: Type-safe pipeline with compile-time checking.
• Fluent Builder API: Readable, chainable pipeline construction.

import { pipelineBuilder } from '@cbnsndwch/zero-contracts';

const mapping = pipelineBuilder<Member>('accounts')
    .match({ bundle: 'ENTERPRISE' })
    .unwind('$members')
    .addFields({
        accountId: '$_id',
        userId: '$members.id',
        role: '$members.role'
    })
    .build();

🏗️ Repository Structure

We use pnpm Workspaces and Turborepo to manage multiple packages effectively:

• apps/zrocket: Unified ZRocket demo showcasing discriminated union tables with MongoDB.
• apps/source-mongodb-server: General-purpose MongoDB change source server.
• libs/zero-contracts: TypeScript contracts and utilities for Zero.
• libs/zero-source-mongodb: MongoDB change source with discriminated unions.

🏗️ Look Inside the ZRocket Demo

The ZRocket demo showcases how multiple Zero tables can be derived from a single MongoDB collection using filter-based discrimination:

• chatsTable: rooms collection with filter { t: 'd' } (direct messages).
• channelsTable: rooms collection with filter { t: 'c' } (public channels).
• systemMessages: messages collection with filter { t: { $exists: true } }.

🛣️ Roadmap & Future Plans

• Stripe Integration: API-based initial sync with webhook support.
• GoHighLevel Integration: Webhook-based change source.
• Deno + Bun Support: Expanding beyond the current Node.js v22+ baseline.

For full details, check out the Repository README.