
About Celesto
Hardware-isolated cloud computers for AI agents, with browser, desktop, shell and file access, pause, resume and forking, via CLI and SDK; Apache-2.0 microVM core you can self-host.
Code Sandboxes
10 code sandboxes tools you can use instead of Celesto, 2 of them open source. Summaries come from each vendor's own site. Links checked Oct 20, 2026.

Hardware-isolated cloud computers for AI agents, with browser, desktop, shell and file access, pause, resume and forking, via CLI and SDK; Apache-2.0 microVM core you can self-host.
At a glance
| Tool | What it does | Open source | Head to head |
|---|---|---|---|
| Agent 37 | Cloud sandboxes for running AI agents, positioned as lower-cost agent infrastructure. | No | Celesto vs Agent 37 |
| AIO Sandbox | All-in-one agent sandbox with browser, shell, file access, VSCode Server, and MCP in one container. | Yes | Celesto vs AIO Sandbox |
| Cloudflare Sandbox SDK | Run untrusted or generated code in Linux VMs or isolated Workers on Cloudflare. | No | Celesto vs Cloudflare Sandbox SDK |
| Cosmonic | WebAssembly sandboxes for agent code, MCP servers and tools, with no access until you grant it: the free Cosmonic Desktop app (public beta) and Cosmonic Control for Kubernetes. Open source core: CNCF wasmCloud. | No | Celesto vs Cosmonic |
| Daytona | Secure sandboxes for running AI-generated code. Its public GitHub repo is archived: core development moved to a private codebase in June 2026. | No | Celesto vs Daytona |
| E2B | Isolated cloud machines for agents to run code, browse, and use tools. | Yes | Celesto vs E2B |
| Modal | Serverless cloud for running, training, and serving AI workloads, including sandboxes. | No | Celesto vs Modal |
| Runloop | Code sandboxes (Devboxes) for AI coding agents, plus evaluations. | No | Not compared yet |
| Vercel Sandbox | Isolated Linux microVMs on Vercel for untrusted or agent-generated code. | No | Not compared yet |
| VoidRun | Isolated microVM sandboxes where AI agents and developers run untrusted code, via REST API, TypeScript and Python SDKs, and an MCP server (beta). | No | Not compared yet |
Code Sandboxes
Cloud sandboxes for running AI agents, positioned as lower-cost agent infrastructure.
All-in-one agent sandbox with browser, shell, file access, VSCode Server, and MCP in one container.
Run untrusted or generated code in Linux VMs or isolated Workers on Cloudflare.
WebAssembly sandboxes for agent code, MCP servers and tools, with no access until you grant it: the free Cosmonic Desktop app (public beta) and Cosmonic Control for Kubernetes. Open source core: CNCF wasmCloud.
Secure sandboxes for running AI-generated code. Its public GitHub repo is archived: core development moved to a private codebase in June 2026.
Isolated cloud machines for agents to run code, browse, and use tools.
Serverless cloud for running, training, and serving AI workloads, including sandboxes.
Code sandboxes (Devboxes) for AI coding agents, plus evaluations.
Isolated Linux microVMs on Vercel for untrusted or agent-generated code.
Isolated microVM sandboxes where AI agents and developers run untrusted code, via REST API, TypeScript and Python SDKs, and an MCP server (beta).
FAQ
Agent Stack Directory lists 10 other code sandboxes tools: Agent 37, AIO Sandbox, Cloudflare Sandbox SDK, Cosmonic, Daytona, E2B, Modal, Runloop, Vercel Sandbox, VoidRun.
Yes. Among the alternatives we list, these are marked open source: AIO Sandbox, E2B.
Hardware-isolated cloud computers for AI agents, with browser, desktop, shell and file access, pause, resume and forking, via CLI and SDK; Apache-2.0 microVM core you can self-host. (Summary based on celesto.ai, link checked 2026-10-20.)