VM Peek

$20 including tax, one-time purchase. Full MIT source included.

VM Peek includes the testvm CLI and its agent skill. The whole bundle costs $20 including tax, with one private repository for both tools. You need an Apple silicon Mac and Tart to run the VM.

My coding agents now test the Mac apps they build in a virtual machine, so they never take over my screen while I work. They drive it with testvm, a small shell script that copies an app into the VM, launches it, takes screenshots and clicks through it.

It works, but the VM has no window. I couldn’t see what the agents were doing in there, which agent was testing what, or whether two of them were in the VM at the same time.

VM Peek shows the screen, active agents and their command history. Here it is in 30 seconds:

The Live view shows the VM’s screen, refreshed every 2 seconds while the window is visible. Under it are the agents that used the VM in the last 3 minutes. Each one shows the prompt that started its chat, the note it left, and the command it’s running right now.

When two chats use the VM at once, an orange banner says so. Their clicks and keys go to whatever app is in front, so one agent can end up clicking in another agent’s app.

Fig 1 · 1/4See which agent is using the VM

It already happened twice. While I was building VM Peek, another Cursor chat spent four and a half minutes in the VM rendering screenshots for one of my other apps, while I clicked around in the same VM, and neither of us knew. Later, while I made the screenshots for the README, another agent opened its app in front of mine halfway through, and that’s the app my screenshot caught. This time the log VM Peek reads told me which agent it was.

Every command, in plain words

The sidebar lists every chat, with the agent that ran it and the project it works on. Click one and you get its timeline, the newest command first.

Commands read like sentences: “Opened Skill Cabinet”, “Took a screenshot of Skill Cabinet”, “Pressed ⌘A”. A click names the control it hit, like “Clicked “Find repeated tasks””. The agent clicks by coordinates, so VM Peek finds the control at that point in the list of controls the agent read just before.

Screenshots show up as thumbnails. Click any command to see it in full: the screenshot, the exact command line, what it printed, and who ran it. There’s also a timeline per app, which tells me which agent put the latest build in the VM before I trust a screenshot of it.

How it knows who’s who

Since every agent goes through testvm, I changed it to log every command to a file in ~/Library/Logs/testvm, with a line when the command starts and one when it ends.

Each line says which agent ran it. Cursor and Codex put the chat’s id in the environment of every command they run. Claude Code doesn’t, so testvm looks for the claude process up the process tree. Anything else counts as me in a terminal.

VM Peek reads the new lines every second. To say what each agent is working on, it finds the chat in the agent’s own transcripts and reads the first prompt.

Agents can also say what they’re testing:

testvm note 'Checking the new sort menu'

The note shows up next to the chat. My skill for the test VM tells every agent to start with one.

The screen comes over the same SSH connection testvm uses. VM Peek only watches: it never clicks, types or opens anything in the VM.

Buy VM Peek and get started

VM Peek costs $20 including tax, paid once. You get the Mac app, the testvm CLI, its agent skill, and full source code for both under the MIT license, so you can read it, change it and build your own version.

After buying, connect your GitHub account in Polar and accept the invitation to the private VM Peek repository. Then open its Releases page to download it. Future updates are available from the same private GitHub Releases page. The same repository contains the testvm/ source folder, the CLI executable, and a combined source archive. There is no separate testvm purchase.

Once you have repository access, download the zip from the latest release, unzip it, and drag VM Peek to your Applications folder. It runs on macOS 15 Sequoia or later. It’s signed with my Apple Developer ID and notarized by Apple, so it opens like any other app you download.

The VM itself runs under Tart, which needs an Apple silicon Mac. The README shows how to install Tart and testvm, create the VM with testvm setup, and tell your agents to use it.

Download updates from the private GitHub Releases page when a new version is available.