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Cloud computer

The isolated machine behind every run — terminal, files, browser, and audit trail.

Last updated July 30, 2026 · 4 min read

Zero doesn't run inside a chat box. Every run gets a cloud computer — an isolated virtual machine with a terminal, a filesystem, standard CLI tools, and a browser. That's what lets Zero do work rather than describe it: clone a repo, run a script, transform a CSV, drive a website that has no API, render a video, and hand you the file at the end.

It also means the work doesn't depend on your laptop. Start a long task, close the lid, and collect the result later.

What's in the machine

  • A terminal. Zero runs real commands — build tools, data transforms, image and video processing, one-off scripts it writes for the task in front of it.
  • A filesystem. Uploads you drop into a chat land here. So do the artifacts Zero produces, until it delivers them somewhere you can reach.
  • Standard tooling. Language runtimes, package managers, and common CLI utilities are already installed, so Zero doesn't spend your credits reinventing them.
  • A browser. For sites with no API, or work that only exists behind a login. See below.
  • Your connectors, brokered. The machine reaches third-party services through VM0's proxy, which injects credentials at the network layer. See Permissions.

Isolation and audit

Each run executes in a Firecracker microVM with hardware-level KVM isolation — the same primitive public clouds use to separate tenants. Two runs never share a machine, and a run can't reach into another chat's files or memory.

Three properties follow from that, and they're on every plan:

  • Sandboxed execution. Whatever Zero installs or breaks inside the machine stays inside it, and the machine goes away when the run ends.
  • No credential exposure. Secrets are injected at the network layer, never handed to the code Zero runs. A leaked script can't print a token that was never in the process.
  • Full audit trail. The agent's HTTP and HTTPS traffic is logged with SHA-256 integrity per run. The chat log shows every call: which account, what it read, what it changed, when.

Browser access

Some work has no API. Zero drives a real browser for it — reading rendered pages, filling forms, clicking through flows, taking screenshots.

When a task needs a browser you can see and touch, Zero opens a remote browser session attached to the chat. You get a live view of that window, and you can take over inside it — sign in, clear a CAPTCHA, approve something — then hand control back and let Zero continue. The session belongs to the chat thread and outlives a single run, so a later run in the same conversation picks up the same window, still signed in.

Idle sessions are eventually reclaimed. Zero extends the lease while a long task keeps a browser open, and a reclaimed session can be resumed from its saved login profile.

Computer use

Computer use is the separate case: instead of a browser inside Zero's machine, Zero operates applications on a desktop host you connect — a machine of yours, with your local apps on it. Right for the software that has no API and no web version at all.

The two are not interchangeable. Browser sessions are for the web; computer use is for a desktop you've deliberately handed over. Computer use is available on every plan.

Working with files

  • Uploads. Drop a PDF, CSV, screenshot, audio file, video, ZIP, or Office document into a chat and it's on the machine before Zero replies. See Web chat for the supported formats.
  • Exports. Anything Zero produces can be downloaded from the chat.
  • Delivery. More often you'll want it somewhere else — a Slack message, a Notion page, a Google Doc, a Gmail draft, or a public URL. See Hosted sites and Automations.

Concurrency

Runs execute in parallel, up to the concurrent-run limit on your plan — 1 on Free, 2 on Pro, 10 on Team, custom on Enterprise. Beyond the limit, new runs queue. This is the practical difference from an agent running on your own machine: kick off three long tasks, walk away, and collect three results.

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