Migrating from older cac

Update your workflow from the old command structure.

If you used cac before the environment manager update, here’s what changed.

Command mapping

Old command	New command	Notes
cac setup	—	No longer needed. Auto-initializes on first use.
cac add us1 proxy	cac env create us1 -p proxy	Proxy is now a -p flag, not a positional arg.
cac us1	cac us1	Unchanged — shortcut for cac env activate us1.
cac ls	cac ls	Unchanged — shortcut for cac env ls.
cac check	cac env check	Moved under env subcommand.
cac stop	cac env deactivate	Renamed. Deactivates the environment entirely.
cac -c	cac env activate <name>	Re-activate by name instead.
cac relay on/off	—	Relay is now automatic (TUN auto-detected).
cac delete	cac self delete	Moved under self subcommand.

Deprecation warnings

All old commands still work but print a warning with the new equivalent:

$ cac add us1 proxy
warning: 'cac add' → 'cac env create <name> -p <proxy>'

$ cac stop
warning: 'cac stop' → 'cac env deactivate'

New capabilities

Feature	Command
Install Claude Code versions	cac claude install latest
Pin environment to a version	cac claude pin 2.1.81
Create env without proxy	cac env create personal
Auto-install versions	cac env create work -c 2.1.81
Update cac	cac self update

Existing environments

Your existing ~/.cac/envs/ environments continue to work. They will show claude: system in cac ls since they don’t have a pinned version. You can pin them:

cac us1                      # activate old env
cac claude pin 2.1.81        # pin to a managed version

The .claude isolation directory (~/.cac/envs/<name>/.claude/) is created automatically on next activation if it doesn’t exist yet.