Cube Sandbox is a high-performance, out-of-the-box secure sandbox service built on RustVMM and KVM. It supports both single-node deployment and easy scaling to multi-node clusters. It is compatible with the E2B SDK and can create a hardware-isolated, fully serviceable sandbox in under 60ms with less than 5MB of memory overhead.
📰 News
Product Highlights
Demos
Benchmarks
In the context of AI Agent code execution, CubeSandbox achieves the perfect balance of security and performance:
| Metric | Docker Container | Traditional VM | CubeSandbox |
|---|
| Isolation Level | Low (Shared Kernel Namespaces) | High (Dedicated Kernel) | Extreme (Dedicated Kernel + eBPF) |
| Boot Speed *Full-OS boot duration | 200ms | Seconds | Sub-millisecond (<60ms) |
| Memory Overhead | Low (Shared Kernel) | High (Full OS) | Ultra-low (Aggressively stripped, <5MB) |
| Deployment Density | High | Low | Extreme (Thousands per node) |
| E2B SDK Compatible | / | / | ✅ Drop-in |
- Cold start benchmarked on bare-metal. 60ms at single concurrency; under 50 concurrent creations, avg 67ms, P95 90ms, P99 137ms — consistently sub-150ms.
- Memory overhead measured with sandbox specs ≤ 32GB. Larger configurations may see a marginal increase.
For detailed metrics on startup latency and resource overhead, see the Core Operations Performance Benchmark Report (bare metal) and the PVM Cloud Server Benchmark Report.
Quick Start
Cube Sandbox requires an x86_64 Linux environment with KVM support.
The guide walks you through everything in four steps — provisioning a server, installing Cube Sandbox, creating a sandbox template, and running your first agent code. No source build needed, up and running in minutes.
First thing after install: open the Web console
After one-click deployment, open in your browser:
http://<control-node IP>:12088
Recommended three steps:
- Check overview — Open Overview, confirm nodes are Ready and capacity looks healthy
- Prepare a template — Install an official preset from Template Store; skip if you already have a
READY template under Templates
- Create a sandbox — Sandboxes → + New sandbox, pick a
READY template, and view live logs on the detail page within seconds
See the full WebUI console guide.
Deep Dive
Architecture
| Component | Responsibility |
|---|
| CubeAPI | High-concurrency REST API Gateway (Rust), compatible with E2B. Swap the URL for seamless migration. |
| CubeMaster | Cluster orchestrator. Receives API requests and dispatches them to corresponding Cubelets. Manages resource scheduling and cluster state. |
| CubeProxy | Reverse proxy, compatible with the E2B protocol, routing requests to the appropriate sandbox instances. |
| Cubelet | Compute node local scheduling component. Manages the complete lifecycle of all sandbox instances on the node. |
| CubeVS | eBPF-based virtual switch, providing kernel-level network isolation and security policy enforcement. |
| CubeEgress | OpenResty-based egress security gateway: L7 domain filtering, credential injection, and access auditing; works with CubeVS kernel policies so sandbox traffic cannot bypass inspection. |
| CubeHypervisor & CubeShim | Virtualization layer — CubeHypervisor manages KVM MicroVMs, CubeShim implements the containerd Shim v2 API to integrate sandboxes into the container runtime. |
👉 For more details, please read the Architecture Design Document and CubeVS Network Model.
Community & Contributing
We welcome contributions of all kinds—whether it's a bug report, feature suggestion, documentation improvement, or code submission!
- 🐞 Found a Bug or have questions? Submit an issue on GitHub Issues.
- 💡 Have an Idea? Join the conversation in GitHub Discussions.
- 🛠️ Want to Code? Check out our CONTRIBUTING.md to learn how to submit a Pull Request.
- 📝 Want to contribute docs? Submit bilingual PRs to our community doc channels: Troubleshooting, Use Cases, and Integrations. Additionally, the Cube 100 Program is now open — we're looking for the first 100 teams running AI agents in production with Cube. Limited to 100 seats. Learn more & apply →
- 💬 Want to Chat? Join our Discord.
Roadmap
Coming soon — see the full roadmap for details.
| Feature | Description |
|---|
| Cross-Node Pause/Resume Performance | Cut pause/resume latency and speed up snapshot transfer so cross-node resume approaches same-node speed |
| E2B API Compatibility | Close remaining gaps with the E2B specification for full drop-in compatibility |
| Sandbox Fault Recovery | Automatic detection and recovery of crashed VMs, stuck shim processes, and network partitions with configurable recovery policies |
| Scheduling & Operations Enhancements | Resource-aware placement, affinity rules, live rebalancing, and node drain with sandbox migration |
| S3 Performance and Cost Optimization | Incremental uploads, better cache, and cheaper storage classes so S3 snapshot/volume I/O stays fast at lower cost |
| Filesystem-Only Snapshots | Snapshot the writable filesystem without a memory dump for cheaper, faster clone/restore when a cold start from disk is enough |
| GPU Sandboxes | Attach host GPUs to sandboxes so Agent and inference workloads can run CUDA inside the isolated VM, with GPU-aware scheduling |
Contributors
Thanks to all contributors:
License
CubeSandbox is released under the Apache License 2.0.
The birth of CubeSandbox stands on the shoulders of open-source giants. Special thanks to Cloud Hypervisor, Kata Containers, virtiofsd, containerd-shim-rs, ttrpc-rust, and others. We have made tailored modifications to some components to fit the CubeSandbox execution model, and the original in-file copyright notices are preserved.
