Devboxes vs. Containers: Why We Run AI Coding Agents in Hardware-Isolated Sandboxes

If you’re building AI coding agents, you already know the rough edges of “vanilla” containers. Agents compile untrusted code, fetch new dependencies, open browsers, and run long, stateful workflows. That mix deserves a stronger boundary than a shared host kernel. Our answer at Runloop is the Devbox: a hardware-isolated, cloud dev environment that behaves like a fresh, secured developer workstation every time.

NIST puts it plainly: “containers … do not offer as clear and concrete of a security boundary as a VM.” NIST Publications

Why isolation matters for agents

AI coding agents write, execute, and iterate on code continuously. They may try tools you didn’t pre-approve, download packages you didn’t vet, or run tests that exercise parts of your system you didn’t anticipate. A kernel-sharing model magnifies blast radius if something goes wrong. Devboxes use micro-VM isolation so every agent operates inside its own hardware-enforced boundary, with strict network policies and a full filesystem—more like handing a developer a secured laptop than tossing another process into a crowded host. Runloop

Speed without the trade-offs

Security is only useful if the experience is fast. Our base Devbox images are optimized to boot in under 200 ms. That means you can spin up fleets of clean, identical environments on demand, run your evaluations, and tear them down again without waiting. For agent teams, it feels like infinite fresh machines that appear just in time. docs.runloop.ai

There’s a scale story too: Devboxes are ephemeral by default, support snapshots when you need state, and slot into your existing pipelines through API and SDKs. You keep your current workflows; you gain repeatability and stronger isolation. docs.runloop.ai+1

The real world is messy: plan for it

Here’s a grounding stat from outside our walls: according to Sysdig’s 2024 Cloud-Native Security and Usage Report, 70% of containers live five minutes or less, while automated cloud attacks can execute in roughly ten minutes. Short-lived infrastructure doesn’t automatically mean safer infrastructure; it often just means incidents unfold fast. Strong defaults and airtight isolation help you contain the unexpected. 2631050.fs1.hubspotusercontent-na1.netSysdig Brand Portal

What changes when you switch

With Devboxes, teams typically report three practical wins:

• Cleaner boundaries: Hardware-level isolation contains risky or untrusted code during agent iteration and testing. NIST PublicationsRunloop

• Faster iteration: Sub-second cold starts and one-command snapshots keep experiments moving instead of waiting on setup. docs.runloop.ai

• Operational sanity: Identical, reproducible environments reduce “works on my machine” drift across repos, branches, and squads. docs.runloop.ai

A better default for agent workflows

We built Devboxes because agents aren’t just functions; they’re long-running, interactive systems that need a real development environment with compilers, debuggers, browsers, and a filesystem. Containers gave the industry incredible portability, but for AI coding agents the safer, more repeatable path is a secured micro-VM that starts instantly and disappears when you’re done. That’s what we run internally, and it’s what our customers use in production today. Runloop

If you want your agents to move fast without widening their blast radius, try them in a Devbox and see the difference in hours, not weeks. PR Newswire+1