skills.rest
catalystctl
catalystctlOFFICIAL
Explore all skills by this author →
WebsiteGitHub

cross-os-sandbox-recommendation

Recommends free lightweight per-OS sandboxing primitives for the catalyst-code harness.

10|1|Updated Jul 7, 2026
Search Tags:#security#cross-platform#sandboxing#seatbelt#landlock#windows job object#command isolation
One-click install
npx skills add https://github.com/catalystctl/catcode --skill cross-os-sandbox-recommendation-catalystctl
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: cross-os-sandbox-recommendation
Source: https://github.com/catalystctl/catcode/tree/main/.catalyst-code/skills/cross-os-sandbox-recommendation
Command: npx skills add https://github.com/catalystctl/catcode --skill cross-os-sandbox-recommendation-catalystctl

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve? Answers the recurring question of which free, lightweight sandboxing approach works across macOS, Linux, and Windows for the catalyst-code harness, without re-investigating the codebase each time. ## Core Features & Use Cases - Grounded Architecture Analysis: Verifies the existing Sandbox enum (None, Firejail, Seatbelt) and the build_bash_command router in core/src/tools.rs before answering. - Per-OS Recommendation Table: Maps macOS to Seatbelt, Linux to Landlock plus unshare -n, and Windows to Job Objects with restricted tokens and AppContainer. - Rejection Rationale: Explains why Docker, gVisor, Firecracker, bubblewrap, Windows Sandbox, and cloud sandboxes do not fit the free, lightweight, per-command requirement. - Use Case: When a maintainer asks what sandboxing to use across all OSes, respond with the stable recommendation and offer to implement Sandbox::Landlock first. ## Quick Start Ask what sandboxing approach is recommended for the harness that works on all operating systems for free and lightweight use.

Frequently Asked Questions about cross-os-sandbox-recommendation

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
What sandboxing works on all operating systems for a coding agent?▼

No single third-party sandbox binary is free, lightweight, and cross-platform. The recommended approach is per-OS native primitives: Seatbelt on macOS, Landlock plus unshare on Linux, and Job Objects with restricted tokens on Windows.

How do I sandbox bash commands on Linux without Docker?▼

Use the Landlock kernel feature (kernel 5.13+) via the landlock crate with Command::pre_exec to restrict filesystem access before exec, combined with unshare -n for network isolation. Firejail remains an opt-in fallback for older kernels.

Can Windows sandbox processes without a full VM?▼

Yes, using Job Objects, restricted tokens, low integrity levels, and per-directory ACLs via CreateProcessW with CREATE_SUSPENDED. AppContainer handles network restriction by omitting the internetClient capability, since pure userspace cannot block networking.

Why not use Docker or gVisor for command sandboxing?▼

Docker and Podman require a Linux VM on macOS and Windows, adding install friction and poor per-command fit. gVisor, Firecracker, and bubblewrap are Linux-only, so none satisfy the free, lightweight, all-OS requirement.

Does the harness already support any sandboxing?▼

Yes, macOS Seatbelt via sandbox-exec with generated .sb allowlist profiles is built in and zero-install. Linux currently relies on external setuid firejail, and Windows has no sandbox, which is the main gap to close.

Related Skills

Explore More Software Engineering Skills→
dnvitidnviti
10

test-scout

Discover test infrastructure, analyze coverage gaps, and plan test strategy.

Community
Intermediate
KhaledMKhaledKhaledMKhaled

mockup-extract

Extract UI components into an isolated mockup sandbox with rewritten imports and stubbed dependencies.

Community
Advanced
AcosmiAcosmi
6

bash

Execute shell commands with sandboxed isolation, timeouts, and policy enforcement.

Community
Advanced
locdinh209locdinh209

e2b-sandbox

Execute code in secure E2B cloud sandboxes with ephemeral resources.

Community
Intermediate