Debugging with Ably CLI

The Ably CLI (@ably/cli, install via npm install -g @ably/cli) lets you observe, test, and simulate Ably operations from the terminal — faster than console.log or browser DevTools.

Discovering commands: Run ably --help for command groups, ably <command> --help for subcommands, flags, and examples. The CLI is self-documenting. This skill teaches what's possible and when to use it.

1. Diagnostic Decision Tree

Messages not arriving
├── Is anyone on the channel?        → list channels with a prefix filter
├── Was anything published?          → check channel history (2 min only without persistence)
├── Can I see messages live?         → subscribe to the channel
├── Test round-trip                  → subscribe in background, publish from main terminal
└── Check channel lifecycle          → subscribe to channel lifecycle logs, or inspect the channel in the dashboard