I’ve been experimenting with Claude CoWork this week, and I wanted to share something that caught me completely off guard — a quirk in how browser automation works when you’ve got the Claude Chrome extension installed on more than one machine.
This isn’t a bug report. It’s more of a “here’s something you really should know before you start automating things” kind of post. And once you understand what’s going on under the hood, it actually opens up some pretty interesting possibilities.
The Setup
I’ve got two machines I regularly work from: a laptop I use when I’m out and about — at a coffee shop, traveling, or just away from my desk — and a desktop back at my office.
I’d installed Claude Desktop and set up Claude CoWork on both machines. I’d also installed the Claude Chrome extension on both. The idea was simple: I wanted to be able to run browser automations regardless of where I was working from, and I figured having everything set up on both machines was the sensible approach.
What I didn’t account for was what would happen when both machines were on at the same time.
The Problem 🤔
I was sitting at my laptop, building out a little automated job in Claude CoWork — a scheduled task that involved some browser automation. Nothing too complex. I’d been testing it and it had been working well, so I went to run it again.
Except this time, I couldn’t see the browser doing anything on my laptop. No Chrome window opening, no automation happening, nothing. I was confused.
What made it weirder was that Claude CoWork was clearly doing something. It takes browser snapshots as it works through a task, and I could see those snapshots in the CoWork interface — it just looked slightly off. The page didn’t quite look right.
And then, out of the corner of my eye, I saw it.
The browser was running on my desktop — the machine across the room.
Claude CoWork had decided, entirely on its own, to run my laptop’s automation job on my desktop.
What’s Actually Happening 🔌
After poking around, I’m fairly confident I understand why this happens — and it comes down to how the Claude Chrome extension works behind the scenes.
When you install the Claude Chrome extension and log in, it doesn’t just sit dormant waiting to be used. It appears to establish and maintain a persistent connection out to the Claude cloud, effectively registering itself as an available automation endpoint. Crucially, this happens even when the browser itself isn’t open.
So when a Claude CoWork job fires and needs to run some browser automation, it reaches out to the Claude cloud and asks: “Which browser connections do I have available?” If you’ve got the extension installed and logged in on two machines under the same Claude account, you’ve got two competing endpoints sitting there waiting.
This is very similar to a pattern called a competing consumer — a concept familiar to anyone who’s worked with message queues or service buses (think Azure Service Bus Relay or similar technologies). The job gets dispatched, and whichever consumer picks it up first wins. In this case, my desktop’s Chrome extension beat my laptop’s to the punch.
The Fix ✅
Once I understood what was happening, the fix was obvious: remove the Chrome extension from whichever machine you don’t want running your automations.
Interestingly, even after I uninstalled Claude Desktop from my desktop, the automation was still routing there — because the Chrome extension was still installed and still maintaining that cloud connection. It was only once I removed the extension entirely that things went back to behaving the way I expected, with the browser running locally on my laptop.
The key takeaway: if you’re running Claude CoWork automations and you have the Chrome extension installed on multiple machines under the same account, you have no guaranteed way of controlling which machine the automation runs on. For now, the simplest solution is to only have the extension installed on the machine you actively want to use for automation.
The Interesting Side of This 🚀
Here’s where it gets genuinely exciting, though.
Once I’d wrapped my head around what was happening, I started thinking about the possibilities this opens up. If Claude CoWork can route browser automation jobs to any machine with the extension installed, you could theoretically have multiple machines running jobs concurrently — all triggered from a single Claude account. One job on your laptop, another on your desktop, maybe a third on a dedicated automation machine.
I haven’t tested this explicitly, and it’s not something I’ve seen documented anywhere yet, but architecturally it makes a lot of sense. It’s essentially the same distributed agent model that enterprise RPA (Robotic Process Automation) platforms have used for years — where you’d have a control centre routing work out to a pool of “bot machines.” Claude CoWork appears to be doing something structurally similar, just without the explicit configuration UI (yet).
My expectation is that Anthropic will eventually introduce some way to target specific machines or groups of machines for automation jobs — something like agent groups or named endpoints. That would bring it much closer to what mature RPA platforms offer, and it would make Claude CoWork genuinely viable for more complex, multi-machine workflows.
One More Thing to Be Aware Of 🔒
While I’m talking about things that happen behind the scenes, there’s one more worth flagging.
During browser automation, Claude CoWork captures screenshots of the browser as it works through a task. These screenshots are streamed back to the Claude cloud service so you can see what’s happening in the CoWork interface. For most use cases this is completely fine — it’s actually a really useful debugging feature.
But if your automation is interacting with anything sensitive — internal dashboards, personal account data, confidential documents — those screenshots are being transmitted. It’s not necessarily a dealbreaker, but it’s something you should be consciously aware of before setting up automations in sensitive environments.
Quick Summary
Here’s the short version if you want to bookmark this:
- Claude CoWork browser automation can run on any machine where the Chrome extension is installed and logged into your account — not just the machine you’re working on.
- The extension maintains a persistent cloud connection, even when Chrome is closed, registering itself as an available automation target.
- If multiple machines are connected, Claude picks one — you can’t currently control which one.
- Fix it by removing the Chrome extension from machines you don’t want used for automation.
- Browser screenshots are streamed to the cloud during automation — be mindful of sensitive on-screen content.
- The multi-machine capability could be powerful for running concurrent automations — watch this space.
I’m only just getting started with Claude CoWork and I’m planning to share more as I learn. If you’ve run into similar quirks, or you’ve found ways to work around them, I’d love to hear about it in the comments.
And if you’d rather watch than read, the full video walkthrough is on my YouTube channel 🎥
