VM Lab
SkillAI & modelsLets your agent run tests inside a disposable Parallels macOS virtual machine and verify GUI automation from outside it.
Then ask your AI: use the VM Lab skill
Details
Instructions available. Your AI can read the instructions. Execution depends on the setup they require.
Account requirements not reviewed. Check the skill instructions before use; Ahel provides instructions and does not run this skill.
No other account needed.
Add it as a step in a pipeline you build on Ahel, or connect Ahel to Claude, ChatGPT, Cursor, Claude Code or Codex and ask your AI to use it.
About this skill
Parallels macOS VM lab: GUI automation, Peekaboo, TCC, Ghostty.
What this skill tells your AI
The instructions your AI receives, as published by steipete/agent-scripts in skills/vm-lab/SKILL.md and read by Ahel’s review.
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
opis needed, follow the 1Password skill and run it only insidetmux. - 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 --unlinkcreates 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.
VM Discovery
List VMs:
prlctl list --all
Get VM status/IP:
prlctl list --info "macOS Tahoe"
Run guest commands as Peter:
prlctl exec "macOS Tahoe" \
'sudo -u steipete -H /bin/zsh -lc '\''source ~/.zprofile 2>/dev/null || true; uname -a'\'''
Capture an independent host-side screenshot:
prlctl capture "macOS Tahoe" --file /tmp/vm-reference.png
sips -g pixelWidth -g pixelHeight /tmp/vm-reference.png
TCC / GUI Attribution
For macOS Screen Recording and Accessibility, the responsible process matters.
prlctl execis headless and can fail to produce useful Screen Recording attribution.- Launch the test command from a visible terminal app in the guest when Screen Recording is involved.
- Ghostty works as a GUI terminal if installed.
- After a first failed capture, check
System Settings > Privacy & Security > Screen & System Audio Recording. permissions statusrun throughprlctl execmay still report Screen Recording false after Ghostty is allowed; validate Screen Recording by rerunning the capture from Ghostty.
Open the Screen Recording pane:
prlctl exec "macOS Tahoe" \
'sudo -u steipete -H open "x-apple.systempreferences:com.apple.preference.security?Privacy_ScreenCapture"'
Open Ghostty:
prlctl exec "macOS Tahoe" 'sudo -u steipete -H open -a Ghostty'
Running Commands Through Ghostty
Best path: create a guest script with prlctl exec, open/focus Ghostty, then type only a short launcher path into the visible terminal.
Guest script pattern:
prlctl exec "macOS Tahoe" 'sudo -u steipete -H /bin/zsh -lc '\''cat > /tmp/run-vm-lab.zsh <<EOF
#!/bin/zsh
source ~/.zprofile 2>/dev/null || true
cd ~/Projects/Peekaboo || exit 1
Apps/CLI/.build/debug/peekaboo image --path /tmp/peekaboo-vm.png --json
rc=$?
echo "EXIT:$rc"
[ -f /tmp/peekaboo-vm.png ] && sips -g pixelWidth -g pixelHeight /tmp/peekaboo-vm.png
echo "Press return to close..."
read _
exit $rc
EOF
chmod +x /tmp/run-vm-lab.zsh
ln -sf /tmp/run-vm-lab.zsh /tmp/r
open -a Ghostty'\'''
Then link the launcher into Ghostty's home directory and type ./r with scripts/parallels_type.py. This avoids unreliable path characters in Parallels key injection.
prlctl exec "macOS Tahoe" \
"sudo -u steipete -H /bin/zsh -lc 'ln -sf /tmp/run-vm-lab.zsh ~/r'"
python3 skills/vm-lab/scripts/parallels_type.py "macOS Tahoe" $'./r\n'
Avoid long command typing. Parallels key injection uses its own key-code table and can be layout-sensitive.
Known Pitfalls
- macOS clipboard APIs may fail from
prlctl exec;pbcopy, AppleScript clipboard, and Peekaboo paste can all fail in headless guest context. open -na Ghostty.app --args -e ...may only focus an existing Ghostty window on macOS; do not assume it runs the command.prlctl execmay re-join argv through a guest shell; for complex payloads, pass one fully shell-quoted command string or create the file with a tiny Python writer.- Parallels
send-key-event --keyuses Parallels key values, not macOS virtual key codes. - For normal typing, send
prlctl send-key-event <vm> --key <key>with no--event; explicitpress/releasecan repeat or stick. Return is an exception: use press then release. - Prefer one
prlctl send-key-event --jsonbatch over many separatesend-key-eventprocesses; separate calls can drift under focus/latency. - Use
PRL_KEY_ENTER = 36,PRL_KEY_SLASH = 61,PRL_KEY_R = 27,PRL_KEY_T = 28,PRL_KEY_M = 58,PRL_KEY_P = 33. - If keystrokes produce garbage, send Return to clear the line, create a shorter launcher, then retry.
- If Peekaboo permission probes hang with Screen Recording missing and emit
SWIFT TASK CONTINUATION MISUSE, record it as a product bug; do not confuse it with the VM harness.
Two-Way Validation
For each GUI action, verify through two independent signals:
- Tool-under-test output: JSON, screenshot file, AX result, or app state.
- External verifier:
prlctl capture, host-side image inspection, file content in guest, or process/window state.
Examples:
- Screenshot: compare Peekaboo image dimensions/content against
prlctl capture. - Click: use Peekaboo to click a test button, then verify both guest app state and host screenshot.
- Type: use Peekaboo to type into a controlled text field, then verify AX value and host screenshot.
- Performance: wrap commands with
/usr/bin/time -p; repeat cold/warm runs; keep outputs in/tmp.
Peekaboo VM Baseline
Inside guest:
cd ~/Projects/Peekaboo
git pull --recurse-submodules
swift build --package-path Apps/CLI
Apps/CLI/.build/debug/peekaboo --version
Apps/CLI/.build/debug/peekaboo permissions status --json
Host-side reference capture:
prlctl capture "macOS Tahoe" --file /tmp/vm-prlctl-reference.png
Guest-side Peekaboo capture through Ghostty:
/tmp/r
Compare:
prlctl exec "macOS Tahoe" \
'sudo -u steipete -H /bin/zsh -lc '\''sips -g pixelWidth -g pixelHeight /tmp/peekaboo-vm.png'\'''
sips -g pixelWidth -g pixelHeight /tmp/vm-prlctl-reference.png
Reporting
When handing off, include only:
- VM name and OS build.
- repo commit tested.
- permission state.
- commands that passed/failed.
- independent verifier result.
- product bugs discovered.
Signals
- GitHub stars
- 7k
- Forks
- 635
- Last commit
- Oct 2026
Advanced
- Item type
- skill
- Key
vm-lab- Source
- github.com/steipete/agent-scripts
github.com/steipete/agent-scripts
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