Auto-Migrating Claude Code with a Throwaway launchd Job — a Script That Deletes Itself When Its Work Is Done

Lily

Posted on Jul 18

• Originally published at dev.to

This continues my "Claude Code environment" series that started with showing rate limits live in the status line. This time it's a one-shot model-migration job — the "throwaway job" pattern, where the job removes its own plist with launchctl unload once it's finished.

Fable 5 shuts down on 2026-07-07. If your Claude Code settings.json has model: fable-5, it will keep pointing at that stale ID from that day onward. You could just run jq by hand, but missing the shutdown moment, or being mid-task and forgetting, is almost guaranteed to happen. So I handed it off to launchd.