MicroVMs: Run isolated sandboxes with full lifecycle control

There are sooooo many sandbox providers out there.

They do spike on different features like:

    - snapshotting and forking
    - good SSH and VPN access for end-users
    - agent-friendly features, like obscuring secrets at network layer

Then there's also the option to use libkrun to run local sandboxes on your own computer. That doesn't scratch the itch for hosted services, but works if your goal is to run agents inside isolated environments for your own work.

I've been working on some open-core stuff[1] to coordinate sandboxes, and we're making changes to have a library that lets people coordinate any number of remote or local sandboxes using any provider, kinda like how the Docker CLI works for managing containers, git repos, and coding agents. Flue[2] is another player in this space, and is more of a pure framework, while we're building it as an interactive product for using sandboxed agents and workflows.

[1] https://github.com/gofixpoint/amika/blob/main/ROADMAP.md

[2]: https://flueframework.com/

For those looking to run agents: the short lifecycle of the typical “sandbox” seems surprisingly limiting to me. I have no actual workflow where I want one of these products. Sometimes a VM can live for 30 minutes, but it also might need to live for a month, and I don’t know beforehand.

This is why I have been avoiding the word sandbox for exe.dev. I don’t think developers agents need something “sandbox” shaped.

It's about time AWS got into the agent sandbox game.

The startups in this space right now don't provide much value on top of the cloud providers they're wrapping. They don't tend to be run by experienced infra people either so they seem very vibecoded, insecure, janky, etc. They're also significantly overpriced because they're marking up already expensive providers.

Something surprising from my own experience is that while there's certainly a huge role for async agents in cloud sandboxes, async agents running locally seem more useful in many cases.

What's the best provider to self-host Firecracker? I feel that AWS is not a safe or cost-effective option for a self-funded startup or small business. Although is anything cost effective anymore? Hetzner just had a massive price hike.

Part of it might just be that I am old and inflation is catching up with my understanding of prices.

But as far as AWS I still have to say no thanks. Imagine some group actually started using my hosted AI agent service for something compute and network intensive. It could turn into $2000 overnight and if I didn't account for one of the numerous types of AWS charges, I might have only collected $500 for credits purchases.

Or it could easily be ten times that. But who am I kidding. No one is going to use my agents. So it doesn't matter if it's gvisor or Firecracker or whatever.

  > Containers launch in seconds, yet their shared-kernel architecture requires significant custom hardening to safely contain untrusted code

That's literally why they made Fargate. It's managed firecracker VMs with containers. They invented firecracker for this purpose. This new product is competing with Fargate, but they don't mention Fargate at all in the announcement.

  > you create a MicroVM Image by supplying a Dockerfile and code packaged as a zip artifact in Amazon S3
  > 
  > MicroVMs support up to 8 hours of total runtime

So you're already using containers with this new thing, same as Fargate! And not only that, it's more limited in runtime than Fargate! The only thing different with this service is stateful file storage, which is actually a problem you later have to engineer around, which is why containers are stateless.

This smells like a competing team building something to capitalize on AI hype, but the product isn't differentiated enough for this to make sense long term. If this was a service called managed AI agents, and you added features specific to AI agents, that has value. But "here's Fargate with a different name" isn't gonna last.

We have this page which compares a whole bunch of sandbox providers in different categories

https://engine.build/lab/agent-sandboxes

Will add MicroVMs there today (and any others that are missing if you let me know!)

Shouldn’t the title be “AWS Lambda MicroVMs”? MicroVMs are an existing concept.

I don’t get it we are paying at least hundreds or maybe thousands per month on ai costs. Just get a regular vm ?

From last week: MicroVMs in Proxmox

https://taoofmac.com/space/blog/2026/06/18/1845

https://github.com/rcarmo/pve-microvm

> MicroVMs support up to 8 hours of total runtime

Does this mean you effectively can't use them as long-lived developer environments? It sounds like even if you suspend them, this is the hard limit on the total time it can run.

This seems roughly similar to Google's Cloud Run gen2 instance types. My understanding is with the second generation, they are running microvms which are bootstrapped from a container image.

What's the point of microVMs for running agents?

Are you guys literally spinning up agents where a 100 ms boot time vs a 3 seconds boot time makes a difference?

I'm asking because I understand the appeal of micro VMs but every time the subject comes up people talk about "isolating agents": what's wrong about isolating agents in a regular VM (or in a container which, itself, is in a VM)?

FWIW I've got my stuff nicely isolated in regular VMs that are regularly up for hours and hours.

It's like the microVMs boots in 100 ms, then the agent does... What? And exits after another 100ms and now you need to launch another one?

What's the use case of "microVMs to isolate agents"?

Interesting, I have recently started working on a project which is similar and fully open source.

Not so subtle plug from yet another sandbox provider, https://instavm.io :

Apart from the above features.

  1. We support more than 32GB disk (as a detachable device, ideal for agentic memory)

  2. We provide egress control

  3. We provide vault for secret injection (to counter prompt injection)

  4. Snapshot / forking.

  5. long lived sandboxes.

Everything supported in APIs and CLI for agents.

Can be used via - npx skills add instavm/skills

What does the actual startup latency look like? Does it depend on the size of the resulting image?

How's this different from Firecracker?

How does this compare to Fly.io

Which is more cheaper for me?

Ideally maybe self hosting would be better?

How does this compare to E2B?

does it have gpu support?