
About boxd
Hardware-isolated Linux VMs for agents and developers that keep running processes, files and shell state between sessions, with fork, snapshot, pause and hibernate, in boxd's cloud or self-hosted.
Code Sandboxes
13 code sandboxes tools you can use instead of boxd, 3 of them open source. Summaries come from each vendor's own site. Links checked Nov 8, 2026.

Hardware-isolated Linux VMs for agents and developers that keep running processes, files and shell state between sessions, with fork, snapshot, pause and hibernate, in boxd's cloud or self-hosted.
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 | boxd vs Agent 37 |
| AIO Sandbox | All-in-one agent sandbox with browser, shell, file access, VSCode Server, and MCP in one container. | Yes | boxd vs AIO Sandbox |
| 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. | Yes | boxd vs Celesto |
| Cloudflare Sandbox SDK | Run untrusted or generated code in Linux VMs or isolated Workers on Cloudflare. | No | boxd 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 | boxd 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 | boxd vs Daytona |
| E2B | Isolated cloud machines for agents to run code, browse, and use tools. | Yes | boxd vs E2B |
| Modal | Serverless cloud for running, training, and serving AI workloads, including sandboxes. | No | Not compared yet |
| Runloop | Code sandboxes (Devboxes) for AI coding agents, plus evaluations. | No | Not compared yet |
| Runtime | Linux sandboxes for agent code, each a Firecracker microVM, billed on active CPU, with pause, forks, snapshots, custom images, an MCP server and SDKs. | No | Not compared yet |
| Sandbox0 | Cloud computers for AI agents that keep the whole writable root filesystem, pause compute between tasks and resume on demand, via API, SDKs and CLI. | 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.
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.
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.
Linux sandboxes for agent code, each a Firecracker microVM, billed on active CPU, with pause, forks, snapshots, custom images, an MCP server and SDKs.
Cloud computers for AI agents that keep the whole writable root filesystem, pause compute between tasks and resume on demand, via API, SDKs and CLI.
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 13 other code sandboxes tools: Agent 37, AIO Sandbox, Celesto, Cloudflare Sandbox SDK, Cosmonic, Daytona, E2B, Modal, Runloop, Runtime, Sandbox0, Vercel Sandbox, VoidRun.
Yes. Among the alternatives we list, these are marked open source: AIO Sandbox, Celesto, E2B.
Hardware-isolated Linux VMs for agents and developers that keep running processes, files and shell state between sessions, with fork, snapshot, pause and hibernate, in boxd's cloud or self-hosted. (Summary based on boxd.sh, link checked 2026-11-08.)