Sandboxes and secure execution tools for coding agents
Isolated sandboxes where agents can run code and tools away from your machine and data. Of the 317 tools on our writing code page, 17 fit this narrower job. By pricing: 14 open source, 1 source-available, 2 pricing on the maker's site. The most-starred open repos here are Deer Flow (83,959 stars), Context Mode (30,192 stars), OpenSandbox (15,907 stars). Most come from the MCP & infra (7), coding (6), security & governance (2) categories.
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Deer Flow
ByteDance's open-source long-horizon agent harness that researches, codes and creates using sandboxes, memory and sub-agents.
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Context Mode
Context window optimizer for coding agents that sandboxes tool output and persists session memory.
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OpenSandbox
Secure, fast sandbox runtime for AI agents to run code.
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CubeSandbox
Lightweight, concurrent sandbox for running AI agent code securely.
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Open SWE
LangChain's asynchronous coding agent that takes work from GitHub issues, Slack or Linear, implements it in an isolated sandbox and opens a pull request.
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microsandbox
Local-first microVM runtime for running untrusted agent code safely.
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Fragments
E2B's open-source Next.js template for AI-generated apps, like Claude Artifacts or v0, with generated code run in secure E2B sandboxes.
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Judge0
Sandboxed code execution system for running untrusted code from people and AI.
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HolmesGPT
CNCF sandbox SRE agent that investigates alerts and incidents.
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Zeroboot
VM sandboxes for running agent code that start in under a millisecond by forking a warm snapshot with copy-on-write memory.
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Mantis
Google's toolkit for AI coding agents to autonomously find, reproduce and patch software vulnerabilities in isolated environments.
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Agent Safehouse
macOS sandbox for local coding agents that limits file and integration access with deny-first policy profiles.
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Cloudflare Sandbox SDK
SDK for running isolated code sandboxes on Cloudflare's network, so agents can execute commands and files safely from a Worker.
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Pydantic Deep Agents
Self-hosted terminal AI assistant and Python framework on Pydantic AI, with tool calling, sandboxed execution, multi-agent teams and checkpoints.
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Mirror CLI
Reflection AI's terminal coding agent that reads code, edits files and runs commands in isolated git worktrees, using the open-weight Beam model by default.
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Conductor
Runs a team of coding agents such as Claude Code and Codex in isolated cloud sandboxes, with Mac and iPhone apps to review and merge their work.
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E2B
Secure cloud sandboxes for running agent-generated code.
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GitHub repos (15)
| Repo | GitHub stars | Licence | Last push |
|---|---|---|---|
| Deer Flow ↗ | 83,959 | MIT | 2026-10-19 |
| Context Mode ↗ | 30,192 | Elastic License 2.0 (source-available) | 2026-10-19 |
| OpenSandbox ↗ | 15,907 | Apache License 2.0 | 2026-10-19 |
| CubeSandbox ↗ | 12,960 | Apache-2.0 (third-party components under their own licences) | 2026-10-19 |
| Open SWE ↗ | 11,034 | MIT | 2026-10-19 |
| microsandbox ↗ | 8,717 | Apache License 2.0 | 2026-10-18 |
| Fragments ↗ | 6,391 | — | 2026-10-13 |
| Judge0 ↗ | 4,482 | GNU GPL v3.0 | 2026-10-18 |
| HolmesGPT ↗ | 3,616 | Apache License 2.0 | 2026-10-19 |
| Zeroboot ↗ | 2,465 | — | — |
| Mantis ↗ | 2,459 | — | 2026-10-17 |
| Agent Safehouse ↗ | 2,110 | — | 2026-10-19 |
| Cloudflare Sandbox SDK ↗ | 1,151 | — | 2026-10-19 |
| Pydantic Deep Agents ↗ | 1,102 | — | 2026-10-06 |
| Mirror CLI ↗ | 180 | — | 2026-10-16 |
15 repos. Stars and licence come from each repo, checked when the listing was last verified.
FAQ
What are the best AI tools for writing code focused on sandboxes and secure execution?
We list 17. The first three by GitHub stars and featured status are Deer Flow: ByteDance's open-source long-horizon agent harness that researches, codes and creates using sandboxes, memory and sub-agents.; Context Mode: Context window optimizer for coding agents that sandboxes tool output and persists session memory.; OpenSandbox: Secure, fast sandbox runtime for AI agents to run code.
Are there free or open-source options?
Yes: 14 open source, 1 source-available, 2 pricing on the maker's site. Pricing is as each maker states it.
More from writing code
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