Ably

Ably is a real-time data streaming platform. Channels are named streams; presence tracks who is connected; push devices receive notifications.

Data Model

• Channels are named message streams. Channel names from the list work as channel_id for single-channel operations.
• Messages are stored per channel. Retrievable with direction and limit. Ephemeral by default — persistence depends on channel config.
• Presence tracks connected clients. Current members and historical presence are separate.
• Push devices and subscriptions link devices to channels for notifications.
• Stats for usage metrics; Time for server timestamp sync.

Gotchas

• Channel ID: Names from the all-channels list are the channel_id for single-channel fetches.
• Message retention: Ephemeral by default. Check channel rules for persistence.