Cowork Local Execution Discontinued | Everything Moves to the Cloud
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Have you ever experienced closing your laptop only to find that your Cowork task had stopped? Starting October 6, Claude Cowork switched to running entirely in the cloud. Here's a breakdown of what changed and what you need to keep in mind.
According to reporting by ITmedia, the "This Computer Only" option has been removed from Claude Cowork.
This option was a setting that ran a VM (a virtual computer inside your computer) on your own PC.
The change affects existing Pro and Max users. Any tasks started on or after October 6 (local time) will run entirely in the cloud.
However, tasks that were already underway before that date will continue running under the settings they started with. There's no need to worry about them stopping abruptly.
Under the previous local execution setup, the model inference — the AI's "brain" — ran on the cloud side, while the working VM ran on your local PC.
Going forward, both model inference and VMs run on Anthropic's servers. Your local PC only displays the interface.
Anthropic's developers explain that each session is assigned its own sandbox — an isolated workspace separated from the outside.
State is not shared with other sessions, and the sandbox is discarded when the session ends. Think of it as a disposable work desk set up fresh each time.
According to ITmedia, the local setup was originally provided "for functionality, safety, and security."
However, two problems existed. First, it placed a heavy load on the machine. Second, tasks would stop when a laptop went to sleep.
Cloud execution eliminates both of these issues. In addition, it becomes possible to hand off work to another device.
For example, you could ask Claude to prepare a document on your work PC, check on its progress from your smartphone on the commute home, and even give additional instructions.
Security concerns also played a role. In July, a vulnerability was reported in the local version of Cowork.
According to reporting site wwwhatsnew, it was discovered by Accomplish AI on July 26 and named "SharedRoot" (CVE-2026-46331). Its severity score is approximately 8 out of 10.
By exploiting a flaw in the Linux kernel inside the VM, an attacker could gain administrator (root) privileges. This would allow access to files on the Mac side that are shared with the VM.
SSH keys, cloud credentials, source code, and similar assets could be put at risk. The number of affected users is estimated at approximately 500,000 macOS users running Cowork locally.
According to the same report, Anthropic closed the report as "informational," on the grounds that the newer version of Cowork defaults to cloud execution.
With the discontinuation of local execution, attacks via the local VM are expected to be no longer viable. That said, Anthropic did not cite the vulnerability as the reason for the discontinuation.
Anthropic's official help page outlines the key considerations when using Cowork in the cloud.
Note that cloud tasks can reference Claude's memory (the content of past conversations). Local execution sessions do not use this memory feature.
It's common to want Claude to create materials based on a quote document sitting on your work PC. With cloud execution, this requires an extra step.
According to ITmedia, when your local device is needed, only folders you have explicitly added in the desktop app can be accessed.
The official help page also states that folders must be attached manually. To access files or tools on your PC, you need to have the Claude desktop app open and connected.
The same applies to local MCP servers, browser operations, and computer use. These features will not work if the app is closed.
For example, if an accounting staff member wants Claude to read through an invoice folder at the end of the month, they would open the app, add that folder, and then make the request. On the other hand, for research tasks that only require online sources, you can leave it running with your PC closed.
The trend of delegating entire jobs to AI isn't unique to Claude. OpenAI has released "ChatGPT Work," and Microsoft 365 Copilot and Google's Gemini for Workspace are also competitors in this space.
What all of these services have in common is cloud-based operation, enabling you to continue tasks from any device — PC, smartphone, or web browser.
According to itechify, the mobile and web versions of Cowork began rolling out to Max users in July. The discontinuation of local execution is a continuation of that direction.
For users in Japan, the key concern is internal company policy. Since files are passed to a cloud sandbox, companies handling confidential materials will need to revisit what they are and are not permitted to share.
Japanese-language official help appears to be available as well. Administrators are advised to review their organization's plan and settings at least once for peace of mind.
As of October 6 (local time). Tasks that were already started before that date will continue running under their original settings until completion.
ITmedia's reporting indicates that Pro and Max users are affected. According to the official help page, cloud execution itself is also available on Team and Enterprise plans.
Tasks running in the cloud will continue. However, tasks that require access to files on your PC or browser operations will not proceed unless the desktop app is open.
Final output files will be saved. Working files that Claude did not return will not persist after the session. The sandbox itself is also discarded at the end of the session.
No. A session continues under the same settings it started with. To start fresh, begin a new session.
Start by taking stock of the files you've been passing to Cowork, and confirm whether each one is appropriate to send to the cloud.
This article is a cross-post from AI Friends.
