I'm building an agent sandbox platform with opinionated customizable templates for general purpose agents using the OpenCode SDK.

The idea is to provide a great CLI experience so it's easy to use an AI client like Claude Code or Codex to launch sandboxes, fetch/retrieve data and prompts, review generated outputs, and manage queues for ask-user questions.

I also plan to add an AI gateway layer, similar to Tailscale Aperture(not affiliated but one of their engineers gave a great talk at AI Engineer it's on YT) for monitoring network access, distributing secrets, and controlling what services/systems a sandbox has access to.

For people building agent workflows, I'd love to hear feedback if you've tried other sandbox solutions.

What was missing and what was the hard part?

What I disliked about the Claude sandbox is that their IPs are blocked by many platforms, which makes webfetch etc. nearly impossible. I had to write a skill to avoid that. Best example is reddit that blocks all access for LLMs. I mean, it's surely understandable why those paltforms do it. But for your own purpose like research and can be a bit annoying.

Docker sandboxes do that. They take quite bit of resources though, almost same as a standard VM.

I need to mount directories or remove after creation easily, like I do with containers.

Gateway would be good too.

Firewall needs more functionality.