#3535th of 118 in Agent frameworks and SDKs
sandcastle
TypeScript library that runs coding agents in isolated sandboxes on git branches
- Stars
- 9k
- License
- MIT
- Last commit
- Nov 2026
- Last release
- Nov 2026
- Language
- TypeScript
865 on 20 Apr 20268,992 on 9 Nov 2026
From GitHub's daily star counts.
Checked on GitHub.
Overview
Sandcastle is a TypeScript library where a single `sandcastle.run()` call starts an AI coding agent inside a sandbox, works on a configurable branch strategy, and merges the resulting commits back. Sandbox providers include Bubblewrap (Linux, WSL2), Seatbelt (macOS), Docker, Podman, and cloud options (Daytona, E2B, Fly.io Sprites, Modal, Vercel), plus custom ones.
Who it is for: TypeScript developers running parallel coding agents in sandboxes
Strengths
- Native OS sandboxes (Bubblewrap, Seatbelt) need no container runtime
- Many providers: Docker, Podman, Daytona, E2B, Fly.io Sprites, Modal, Vercel
- Branch strategies and merge-back suit parallel agents and review pipelines
- Custom sandbox providers can be written; hooks and structured output are documented
Weaknesses
- Library only: no UI, you write TypeScript to orchestrate runs
- Cloud providers require accounts with third-party services
- No Windows-native sandbox listed; Windows users need WSL2
What it needs
- no GPU
- Needs Node.js, Bubblewrap (Linux/WSL2), Docker or Podman (optional), Daytona, E2B, Fly.io Sprites, Modal or Vercel (optional)
What changed
- v0.13.0 ↗ (opens in a new tab)Security fix
“Security fixes. The host's .git is mounted read-only in bind-mount sandboxes, and host-side git ignores hooks and config that run programs. Sync-out refuses paths that leave the worktree, and fetch o…”
From the release notes. No flag means the note does not say so, not that the upgrade is safe.
Quick answers
Is sandcastle open source?
Yes. Its code is on GitHub under the MIT license.
Does sandcastle need a GPU?
No, it runs without one.
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