Agent skill · software engineering · steipete
vm-lab
Parallels macOS VM lab: GUI automation, Peekaboo, TCC, Ghostty.
Why this skill is useful
Adds specific commands and workflows for managing macOS VMs with Parallels that are not widely documented.
What it needs
Requires parallels installed locally. About 4k tokens when loaded. Last updated 2026-08-06. 6,510 stars on the source repository.
What this skill does
VM Lab Use this when the task needs a clean macOS VM to test GUI automation, TCC prompts, screenshot capture, clicking, typing, performance, or "two-way validation" of Peekaboo-like tools. Core idea: run the tool under test inside the guest, but verify it from outside the guest with Parallels screenshots and host-side observations. Do not close apps you do not own. Safety Rules Only task-owned clones are disposable. Preserve source/golden snapshots, recovery VMs, and other tasks' VMs; never reset, revert, or delete their snapshots. Never access inherited guest credentials or bypass login/startup security to bootstrap a clone. Never print secrets. If op is needed, follow the 1Password skill and run it only inside tmux. Prefer fresh app windows you create yourself: TextEdit, a local HTML test page, or a small test app. Limit host writes to task-owned temporary diagnostics and explicitly authorized clone recovery. Never change global Bash/Codex settings for a lab workaround. For git repos inside the VM, use HTTPS remotes and normal branch discipline. Bootstrap Preflight Before guest automation, confirm the exact task-owned VM UUID and snapshot provenance; the names below are examples, not permission to operate an existing VM. Apple-VZ clone fails to boot: verify the active raw disk's contents, not just clone success or logical size. A sparse linked child alone does not prove a broken chain; clone --unlink creates another clone, not an in-place repair. Packaging hangs before its first output: inspect the task-owned shell process and heredoc redirection before changing product code or build guards. A system-Bash retry must also pin PATH-resolved child shells, for that invocation only. Use Bootstrap diagnostics for read-only checks, evidence limits, and narrowly scoped recovery boundaries. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills steipete/vm-lab