OpenSandbox review

OpenSandbox at a glance

Category

Sandboxes and runtimes

Maintained by

opensandbox-group (organization, @opensandbox-group on GitHub)

License

Apache 2.0

Language

Python, Go, Kotlin

Repository

github.com/opensandbox-group/OpenSandbox

Website

open-sandbox.ai

PyPI package

opensandbox 1.1.1

Latest release

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 and start using 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 to know

• 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.

Is OpenSandbox growing? Usage data

In the week of Oct 25–31, 2026, OpenSandbox ranked #59 on the Devtoolwatch Board and #1 in Sandboxes and runtimes, with a momentum score of 74 out of 100. Its main package had 328.9k downloads that week, +68% against its own 4-week average.

The Board ranks tools by four signals each week: new stars, new stars for the repo's size, added downloads and download growth beyond the market. How the ranking works.

OpenSandbox alternatives

Other AI sandboxes and runtimes on the Board in the week of Oct 25–31, 2026, by momentum:

All AI sandboxes and runtimes, ranked

Recent OpenSandbox releases

• release-1.2.0-rc.2 (pre-release), Oct 21, 2026
• release-1.2.0-rc.1, Oct 15, 2026
• release-1.1.1, Oct 9, 2026
• release-1.1.1-rc.1, Sep 28, 2026
• release-1.1.0, Sep 21, 2026

Sources

1. opensandbox-group/OpenSandbox on GitHub
2. OpenSandbox README
3. opensandbox on PyPI
4. OpenSandbox website
5. Release release-1.2.0-rc.2 (Oct 21, 2026)
6. Release release-1.2.0-rc.1 (Oct 15, 2026)
7. Release release-1.1.1 (Oct 9, 2026)
8. Devtoolwatch Board, the week of Oct 25–31, 2026

OpenSandbox README badge

Maintainers can show the tool's weekly Board rank in their README:

[![Devtoolwatch](https://index.devtoolwatch.com/badge/opensandbox-group-opensandbox.svg)](https://index.devtoolwatch.com/tools/opensandbox-group-opensandbox/)