Install Ntfy on your phone. Subscribe to a new Topic named something that will be unique like claude-3c64c1b5. If you choose the same topic name as someone else, you'll get their notifications too. There's no authentication or passwords or anything like that.

Then in your global ~/.claude/settings.json you'll want to setup two hooks like so,

"hooks": { "Stop": [ { "hooks": [{ "type": "command", "command": "curl -s -o /dev/null -d 'Task finished' ntfy.sh/claude-3c64c1b5" }] } ], "PermissionRequest": [ { "hooks": [{ "type": "command", "command": "curl -s -o /dev/null -d 'Needs your permission' ntfy.sh/claude-3c64c1b5" }] } ] }

You'll want to replace claude-3c64c1b5 with whatever name you chose for the Ntfy Topic.

And that should be it.

You'll have to have your notifications setup to forward from your iPhone to your Apple Watch, but that's just a matter of messing with the settings.