itzaks/ably-realtime-skill

Overview

This skill is a professional guide to using Ably Realtime in React and TypeScript apps for building pub-sub messaging, presence-aware collaborative UI, shared state, full chat, and database synchronization. It summarizes feature choices, setup patterns, React hooks, and integration strategies to get production-ready realtime behavior with minimal friction. The guide focuses on concrete examples and patterns you can reuse in apps.

How this skill works

The guide explains how to create a single Realtime client, wrap React with Ably providers, and use Ably abstractions: Channels for pub-sub, Spaces for participant state, LiveObjects for conflict-free shared state, Chat SDK for messaging, and LiveSync for database-to-client sync. It shows common hooks (useChannel, usePresence, useMessages, useCursors, useTyping) and patterns like loading history before subscribing, optimistic updates, and the outbox pattern for transactional DB changes.

When to use it

• Use Channels for notifications, live updates, and custom event broadcasting.
• Use Spaces when building collaborative UIs with cursors, avatar stacks, or component locking.
• Use LiveObjects for synchronized shared state: counters, maps, game state, or CRDT-like updates.
• Use the Chat SDK for feature-rich messaging: rooms, typing indicators, reactions, and history.
• Use LiveSync to broadcast database changes from Postgres/Neon and implement the outbox pattern.

Best practices

• Create the Realtime client outside React components to avoid reconnect loops.
• Prefer token-based auth in production; use API keys only for local/testing.
• Load history before subscribing to avoid missing recent events.
• Use optimistic updates with mutation IDs and reconcile on confirmed events.
• Keep presence data minimal (profile id, avatar, status) and update sparingly.

Example use cases

• Real-time notification panel using a ChannelProvider and useChannel to publish/subscribe.
• Collaborative editor with Spaces for live cursors, member lists, and component locking.
• Multiplayer lobby using LiveObjects LiveCounter and LiveMap to sync scores and players.
• Support chat using Chat SDK: load previous messages, send, show typing indicators and reactions.
• Transactional DB sync with LiveSync: write to outbox inside a DB transaction and notify clients.