Definition
Agent sandbox
An agent sandbox is an isolated computer, often backed by a microVM, where an AI agent does real work: opens a browser, runs shell commands, starts services, and calls APIs under policy constraints. It is not just a place to execute a script snippet.
Why it matters
Agents do not only write code. They click through your app, run CLIs, install packages, and reach external services. Sandboxes limit blast radius when something goes wrong.
How Islo helps
Islo provides persistent agent computers with a real dev environment, browser, gateway policies, and audit, not one-off execution in an empty container.
Sandbox vs empty container
Running `docker run` with a repo checked out is enough for a script. Agents need more: a browser to click through flows, long-lived processes like Postgres and Redis, package installs that persist, and network access scoped to specific APIs. An agent sandbox bundles isolation with that full computer surface so the agent can work like an engineer at a desk, not like a CI job that exits after one command.
When you need one
Any time an agent runs code you did not write, reaches production-adjacent services, or works unattended for hours, a sandbox is the right boundary. That covers PR review on a live stack, running user-supplied code in a product, and eval suites where agents might try to cheat. Chat-only assistants on trusted local repos are the exception, not the default for autonomous workflows.
Keep reading
Common questions
Is a sandbox the same as a container?
Containers provide isolation. Agent sandboxes often add a full computer surface, network policy, credential injection, and persistence for long runs.
Can agents use a browser in the sandbox?
Yes. Islo computers include browser automation so agents can verify UI flows, not just run unit tests.
Do I need a sandbox for every agent call?
For untrusted or production-adjacent work, yes. For read-only chat, less critical.
What is the difference between E2B and Islo?
See /compare/e2b for a feature comparison.
Are sandboxes deleted after each run?
On Islo you can discard, snapshot, or keep computers running between jobs.