# OpenSandbox review

> OpenSandbox is a sandbox runtime that gives AI agents isolated environments to run code, commands, files, browsers, and desktops on your own infrastructure.

Devtoolwatch Board, the week of Oct 25–31, 2026. Canonical page: https://index.devtoolwatch.com/tools/opensandbox-group-opensandbox/

## TL;DR

OpenSandbox runs AI agents in isolated sandboxes on your own infrastructure. It starts locally with Docker and deploys on Kubernetes through one sandbox API. It is for teams building coding agents, code execution, browser automation, or agent evaluation. It offers SDKs in five languages, a CLI, and an MCP server.

## OpenSandbox at a glance

- **Category:** [Sandboxes and runtimes](https://index.devtoolwatch.com/categories/sandboxes-and-runtimes/)
- **Maintained by:** opensandbox-group (organization, [@opensandbox-group](https://github.com/opensandbox-group) on GitHub)
- **License:** Apache 2.0
- **Language:** Python, Go, Kotlin
- **Repository:** [github.com/opensandbox-group/OpenSandbox](https://github.com/opensandbox-group/OpenSandbox)
- **Website:** [open-sandbox.ai](https://open-sandbox.ai)
- **PyPI package:** [opensandbox](https://pypi.org/project/opensandbox/) 1.1.1
- **Latest release:** [release-1.2.0-rc.1](https://github.com/opensandbox-group/OpenSandbox/releases/tag/release-1.2.0-rc.1) on GitHub, Oct 15, 2026
- **First published:** Dec 17, 2025

## What OpenSandbox does

- OpenSandbox executes shell commands, manages files, and runs code inside isolated sandboxes through built-in APIs.
- OpenSandbox provisions, monitors, renews, pauses, resumes, and terminates sandbox instances on Docker and Kubernetes runtimes.
- OpenSandbox routes inbound traffic through an ingress gateway and controls outbound access with per-sandbox egress policies.
- OpenSandbox's Credential Vault lets agents call external services without exposing real credentials to sandbox workloads.
- OpenSandbox's Fast Sandbox runtime uses Firecracker sandboxes on Kubernetes that support pause/resume with memory and disk state preserved.
- OpenSandbox supports resource pools and batch creation for agent evaluation and RL training workloads.
- OpenSandbox can host VS Code Web and desktop-like environments for remote development.

### How it works

You run the OpenSandbox server locally with Docker or deploy it on Kubernetes. Applications talk to it through SDKs for Python, Java/Kotlin, TypeScript/JavaScript, C#/.NET, or Go. The osb CLI covers the same workflow from a terminal. An MCP server exposes sandbox creation, command execution, and text file operations to MCP clients such as Claude Code and Cursor.

## How to install OpenSandbox

**Start the sandbox server**

```
uvx opensandbox-server init-config ~/.sandbox.toml --example docker
```

**Python SDK**

```
pip install opensandbox
```

**CLI**

```
pip install opensandbox-cli
```

### Requirements

- Docker is required for local execution.
- Python 3.10 or later is required for examples and the local runtime.
- Kubernetes is needed for cluster deployment and the Fast Sandbox runtime.

### First steps

1. Create a config file with uvx opensandbox-server init-config ~/.sandbox.toml --example docker, then start the server with uvx opensandbox-server.
2. Install the Python SDK with uv pip install opensandbox.
3. Create a sandbox from the alpine image with Sandbox.create and run a command using sandbox.commands.run.
4. Call sandbox.destroy() when finished to clean up the sandbox.

## Who OpenSandbox is for

- Teams running coding agents such as Claude Code or Codex CLI in isolated environments.
- Applications that execute model-generated code and need isolated, reproducible environments.
- Browser and desktop automation with Playwright or Chrome under controlled networking.
- Agent evaluation and RL training that need a separate sandbox per trial.

### Limitations

- OpenSandbox is self-hosted: you run the server on your own Docker or Kubernetes infrastructure.
- OpenSandbox's Fast Sandbox runtime with Firecracker targets Kubernetes, not local Docker setups.
- OpenSandbox 1.1.0 server installs from PyPI fail at import time; release notes say users should upgrade to 1.1.1.
- In 1.2.0-rc.2, fast sandboxes reject port-scoped network rules until enforcement lands.

## Usage data (the week of Oct 25–31, 2026)

- Board rank: #59 overall, #1 in Sandboxes and runtimes, momentum score 74
- Downloads that week: 328.9k (+68% vs 4-week average)
- New GitHub stars per week (last 12 weeks): Aug 9: 1.2k; Aug 16: 1k; Aug 23: 244; Aug 30: 176; Sep 6: 161; Sep 13: 266; Sep 20: 124; Sep 27: 138; Oct 4: 129; Oct 11: 159; Oct 18: 213; Oct 25: 216

## OpenSandbox alternatives

| Rank | Tool | Stars | Downloads/wk |
|---|---|---|---|
| #2 | [microsandbox](https://index.devtoolwatch.com/tools/microsandbox/) | 8.9k | 26.8k |
| #3 | [E2B](https://index.devtoolwatch.com/tools/e2b/) | 14.6k | 5M |
| #4 | [Agent Sandbox](https://index.devtoolwatch.com/tools/kubernetes-sigs-agent-sandbox/) | 4.5k | – |
| #5 | [Trigger.dev](https://index.devtoolwatch.com/tools/trigger-dev/) | 16.7k | 1.7M |
| #6 | [Inngest](https://index.devtoolwatch.com/tools/inngest/) | 6k | 3.7M |
| #7 | [Cloudflare Sandbox SDK](https://index.devtoolwatch.com/tools/cloudflare-sandbox/) | 1.2k | 1.2M |

## OpenSandbox FAQ

### Is OpenSandbox free and open source?

Yes. OpenSandbox's source code is on GitHub (opensandbox-group/OpenSandbox) under the Apache 2.0 license, so you can use it for free.

### How do I install OpenSandbox?

Run `uvx opensandbox-server init-config ~/.sandbox.toml --example docker`. The opensandbox package needs Python 3.10 or newer. The install section above has the other options from the project's README.

### Is OpenSandbox still maintained?

Yes. The opensandbox-group/OpenSandbox repository was last updated on Oct 21, 2026, and the latest release, release-1.2.0-rc.1 on GitHub, came out on Oct 15, 2026.

### How popular is OpenSandbox?

OpenSandbox has 16.3k GitHub stars as of Nov 1, 2026. It gained 216 new stars in the week of Oct 25–31, 2026, against a 12-week average of 334 a week. Its main package had 328.9k downloads that week, +68% against its own 4-week average. That made it #1 among AI sandboxes and runtimes on the Devtoolwatch Board.

### What are the best alternatives to OpenSandbox?

Other AI sandboxes and runtimes on the Devtoolwatch Board in the week of Oct 25–31, 2026, by momentum: microsandbox (#2), E2B (#3), Agent Sandbox (#4), Trigger.dev (#5), Inngest (#6). The alternatives table above has their numbers.

### Can OpenSandbox run VS Code?

Yes. OpenSandbox can host VS Code Web and desktop-like environments for remote development workflows. The example catalog includes remote development environments.

### Does OpenSandbox work with MCP clients like Claude Code and Cursor?

Yes. OpenSandbox ships an MCP server, opensandbox-mcp, that exposes sandbox creation, command execution, and text file operations to MCP-capable clients such as Claude Code and Cursor.

### Which languages does OpenSandbox have SDKs for?

OpenSandbox has SDKs for Python, Java/Kotlin, JavaScript/TypeScript, C#/.NET, and Go. They are built on standardized lifecycle and execution protocols.

### Can OpenSandbox pause and resume sandboxes?

Yes. OpenSandbox's Firecracker sandboxes support pause/resume with memory and disk state preserved. The 1.2.0 release candidates add opt-in auto-pause and wake-on-access for fast sandboxes.

### How does OpenSandbox protect credentials?

OpenSandbox's Credential Vault lets agents call external services without exposing real credentials to sandbox workloads. Outbound access is also governed by per-sandbox egress policies.

## Sources

1. [opensandbox-group/OpenSandbox on GitHub](https://github.com/opensandbox-group/OpenSandbox)
2. [OpenSandbox README](https://github.com/opensandbox-group/OpenSandbox/blob/main/README.md)
3. [opensandbox on PyPI](https://pypi.org/project/opensandbox/)
4. [OpenSandbox website](https://open-sandbox.ai)
5. [Release release-1.2.0-rc.2 (Oct 21, 2026)](https://github.com/opensandbox-group/OpenSandbox/releases/tag/release-1.2.0-rc.2)
6. [Release release-1.2.0-rc.1 (Oct 15, 2026)](https://github.com/opensandbox-group/OpenSandbox/releases/tag/release-1.2.0-rc.1)
7. [Release release-1.1.1 (Oct 9, 2026)](https://github.com/opensandbox-group/OpenSandbox/releases/tag/release-1.1.1)
8. [Devtoolwatch Board, the week of Oct 25–31, 2026](https://index.devtoolwatch.com/)