agent-sandbox vs CubeSandbox
Kubernetes SIG Apps' Sandbox CRD and controller: stateful singleton pods with stable identity and persistent storage for agent runtimes and RL — templates, claims, warm pools; gVisor/Kata isolation. — versus — Hardware-isolated microVM sandboxes for AI agents — sub-60ms boot, <5MB overhead, E2B-compatible API, self-hosted on your own KVM nodes.
Same job — self-hosted sandboxes for agent code — at a different layer: CubeSandbox is its own KVM microVM runtime with an E2B-compatible API; agent-sandbox orchestrates pods and delegates isolation to gVisor or Kata.
| agent-sandbox | CubeSandbox | |
|---|---|---|
| Stars | 4.0k | 13k |
| Forks | 530 | 1.2k |
| Language | Go | Rust |
| License | Apache-2.0 | NOASSERTION |
| Last activity | 3 days ago | 4 days ago |
| Topics | sandboxes, agents | sandboxes, agents, local |
| Curated connections | 5 | 16 |
agent-sandbox — the curator's take
Pick agent-sandbox when you already run Kubernetes and want agent sandboxes as a declarative, first-class resource: one long-lived pod per agent with a stable hostname, persistent volume, pause/resume and scheduled deletion, plus warm pools so claims start fast. It's upstream Kubernetes (SIG Apps), so it's the boring, vendor-neutral choice, with Go and Python SDKs and a router for reaching pods. The catch is in its own scope note: it orchestrates, it doesn't isolate. Security comes from the RuntimeClass you configure (gVisor, Kata); on the default runtime it's just a pod. No cluster? A microVM runtime like cubesandbox or a hosted sandbox SDK is far less machinery.
CubeSandbox — the curator's take
Reach for CubeSandbox the moment your agents execute model-generated code and "just run it in Docker" stops feeling safe — it gives every tool call a disposable hardware-isolated microVM with E2B's SDK ergonomics, minus the SaaS bill, plus snapshot/rollback of any sandbox state. The catch: it's real infrastructure — you need KVM-capable Linux hosts and someone willing to operate them. Prototyping a single local agent? A container or E2B's hosted tier is less machinery. It's a runtime, not a framework — you still bring LangGraph/AutoGen/whatever on top.