Ckeditor5 Testing
TriliumNext/Trilium
Testing CKEditor 5 plugins in the Trilium monorepo. An agent skill from TriliumNext/Trilium.
Working inside the Claude Code cloud sandbox (Claude Code on the web, remote sessions, scheduled runs).
Install Cloud Sandbox
$ npx skills add dxos/dxos --skill cloud-sandbox -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install dxos/dxos cloud-sandbox --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/dxos/dxos.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/cloud-sandbox .claude/skills/cloud-sandbox && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "cloud-sandbox" agent skill from https://github.com/dxos/dxos/tree/main/.agents/skills/cloud-sandbox into .claude/skills/cloud-sandbox/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cloud-sandbox", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/dxos/dxos/tree/main/.agents/skills/cloud-sandboxType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add dxos/dxos --skill cloud-sandbox -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install dxos/dxos cloud-sandbox --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/dxos/dxos.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/cloud-sandbox .agents/skills/cloud-sandbox && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "cloud-sandbox" agent skill from https://github.com/dxos/dxos/tree/main/.agents/skills/cloud-sandbox into .agents/skills/cloud-sandbox/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cloud-sandbox", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add dxos/dxos --skill cloud-sandbox -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install dxos/dxos cloud-sandbox --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/dxos/dxos.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/cloud-sandbox .cursor/skills/cloud-sandbox && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "cloud-sandbox" agent skill from https://github.com/dxos/dxos/tree/main/.agents/skills/cloud-sandbox into .cursor/skills/cloud-sandbox/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cloud-sandbox", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/dxos/dxos.git --path .agents/skills/cloud-sandbox--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add dxos/dxos --skill cloud-sandbox -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install dxos/dxos cloud-sandbox --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/dxos/dxos.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/cloud-sandbox .gemini/skills/cloud-sandbox && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "cloud-sandbox" agent skill from https://github.com/dxos/dxos/tree/main/.agents/skills/cloud-sandbox into .gemini/skills/cloud-sandbox/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cloud-sandbox", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install dxos/dxos cloud-sandboxInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add dxos/dxos --skill cloud-sandbox -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/dxos/dxos.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/cloud-sandbox .github/skills/cloud-sandbox && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "cloud-sandbox" agent skill from https://github.com/dxos/dxos/tree/main/.agents/skills/cloud-sandbox into .github/skills/cloud-sandbox/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cloud-sandbox", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add dxos/dxos --skill cloud-sandbox -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install dxos/dxos cloud-sandbox --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/dxos/dxos.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/cloud-sandbox .opencode/skills/cloud-sandbox && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "cloud-sandbox" agent skill from https://github.com/dxos/dxos/tree/main/.agents/skills/cloud-sandbox into .opencode/skills/cloud-sandbox/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cloud-sandbox", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
cloud-sandbox- GitHub stars
- 525
- Token cost
- ~3.9k tokens
- SKILL.md length
- 1,847 words
- Files
- 1
- Skills in repo
- 41
- Repo updated
- First seen
- Licence
- Custom licence
At a glance
Working inside the Claude Code cloud sandbox (Claude Code on the web, remote sessions, scheduled runs).
- CLAUDECODEREMOTE is set
- SKILL.md covers Detect it, Project hooks run; plugins do…, Tooling not on PATH and Nothing is prebuilt, and…, plus 3 more sections
- Calls git, pnpm and gh; reaches dxos.network
- Oxfmt are command not found
What it does
Cloud Sandbox is an agent skill from dxos/dxos. Working inside the Claude Code cloud sandbox (Claude Code on the web, remote sessions, scheduled runs). Use when CLAUDECODEREMOTE is set; when moon, gh, or oxfmt are "command not found"; when Chromium or Playwright fails with ERRCONNECTIONRESET or a TLS error against an HTTPS host that curl reaches fine; when /dxos:project answers Unknown command or a plugin's skills are missing from the session; or when a build or dev server unexpectedly triggers a full pnpm install.
Its SKILL.md is about 3.9k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Testing & QA, covering Browser testing. It works with Playwright and pnpm. The repository describes itself as: TypeScript implementation of the DXOS protocols, SDK, toolchain and Composer.
When your agent uses it
- CLAUDECODEREMOTE is set
- Oxfmt are command not found
- Playwright fails with ERRCONNECTIONRESET
- A TLS error against an HTTPS host that curl reaches fine
Example prompts
- “command not found”
- “/cloud-sandbox”
What it can do on your machine
Read from SKILL.md and the folder at commit f0fc12a. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
gitpnpmghplaywrightbashclaudecurl
From the folder's file list and the shell code blocks in SKILL.md.
Network
Hosts in commands or code, which the agent is likely to contact:
dxos.network
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Cloud Sandbox loads about 3.9k tokens when it runs. Until then it costs about 125 tokens; SKILL.md has 1,847 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
Its licence (Custom licence) doesn't allow us to republish the file, so here is its outline and opening line. It has 1,847 words (~3,949 tokens).
“The sandbox is an ephemeral Linux container running the agent against a fresh clone at /home/user/. It is not the environment AGENTS.md and .claude/CLAUDE.md assume, and several of their instructions do not hold here.”
- name
- cloud-sandbox
Files
Just SKILL.md in .agents/skills/cloud-sandbox of dxos/dxos.
Open the folder on GitHubat commit f0fc12a
Compare with similar skills
Cloud Sandbox next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Cloud Sandbox this skilldxos/dxos | 525 | — | ~3.9k | Automated safety check: Pass | Custom licence | |
| Ckeditor5 TestingTriliumNext/Trilium | 38k | — | ~3.3k | Automated safety check: Pass | AGPL-3.0 | |
| Agent Integration ReplayComfy-Org/ComfyUI_frontend | 2.1k | — | ~805 | Automated safety check: Notes | GPL-3.0 | |
| UI Previewtingly-dev/tingly-box | 351 | — | ~2k | Automated safety check: Notes | MPL-2.0 | |
| Tuistoryremorses/tuistory | 366 | — | ~2.4k | Automated safety check: Pass | None | |
| E2E VerificationChorus-AIDLC/Chorus | 1.2k | — | ~1.5k | Automated safety check: Notes | AGPL-3.0 |
Similar skills
Agent Integration Replay
Comfy-Org/ComfyUI_frontend
Replay recorded agent conversations as Playwright tests against the real chat panel and canvas.
UI Preview
tingly-dev/tingly-box
Capture headless-Chrome screenshots of the tingly-box frontend (running locally in mock mode) so frontend changes can be visually verified in environments without a real browser.
Tuistory
remorses/tuistory
tmux for AI agents. An agent skill from remorses/tuistory.
E2E Verification
Chorus-AIDLC/Chorus
A skill your agent uses when manually verifying a Chorus frontend change in a real browser — finding local login credentials, driving the running dev server with the Playwright MCP, logging in…
E2E Playwright
Asvarox/allkaraoke
Run, write, and debug Playwright E2E tests for this project.
More from dxos/dxos
All 41 skills in this repoAgentic Review
dxos/dxos
Run the rule-driven agentic code review — discover rule blocks in the repo's .mdl files, prepare per-rule review groups (full project by default; diff-only with --pr-only), spawn one focused Sonnet…
Composer Forensics
dxos/dxos
Forensically inspect and repair Composer browser profiles — offline (Chrome OPFS / SQLite extract) or live via /recovery.html debug port.
Migrate Oxfmt
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Guide for migrating a project from Prettier or Biome to Oxfmt.
Moon
dxos/dxos
This skill should be used when the user asks to "configure moon", "set up moonrepo", "create moon tasks", "run moon commands", "configure moon workspace", "add moon project", "moon ci setup", "moon…
Subduction Policy
dxos/dxos
Reference for SubductionPolicy (the four hooks authorizeConnect, authorizeFetch, authorizePut, filterAuthorizedFetch passed via Subduction.hydrate(..., policy) or new Repo({ subductionPolicy })).
Autocue
dxos/dxos
Record a demo of the running app that the agent drives itself — a .mdl QA test or an ad-hoc walkthrough — as a captioned .webm (or a screenshot), trimmed of dead air and ready to attach.
Related
Works with
Categories
Questions about Cloud Sandbox
What does Cloud Sandbox do?
Working inside the Claude Code cloud sandbox (Claude Code on the web, remote sessions, scheduled runs). Cloud Sandbox is an agent skill from dxos/dxos. Working inside the Claude Code cloud sandbox (Claude Code on the web, remote sessions, scheduled runs).
When should I use Cloud Sandbox?
Cloud Sandbox fits situations like: CLAUDECODEREMOTE is set; oxfmt are command not found; playwright fails with ERRCONNECTIONRESET; A TLS error against an HTTPS host that curl reaches fine.
How do I install Cloud Sandbox in Claude Code?
Run `npx skills add dxos/dxos --skill cloud-sandbox -a claude-code`. Or copy the skill folder (.agents/skills/cloud-sandbox in dxos/dxos) into .claude/skills/cloud-sandbox in your project. Claude Code loads it when a task matches its description.
How do I install Cloud Sandbox in Codex?
Run `npx skills add dxos/dxos --skill cloud-sandbox -a codex`. Or copy the skill folder (.agents/skills/cloud-sandbox in dxos/dxos) into .agents/skills/cloud-sandbox in your project. Codex loads it when a task matches its description.
Can I use Cloud Sandbox in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add dxos/dxos --skill cloud-sandbox -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/cloud-sandbox, .gemini/skills/cloud-sandbox, .github/skills/cloud-sandbox and .opencode/skills/cloud-sandbox in your project.
What does Cloud Sandbox need to run?
Going by SKILL.md and its folder, Cloud Sandbox needs the command-line tools its instructions call (git, pnpm, gh, playwright, bash and claude).
Does Cloud Sandbox access the network?
SKILL.md names 1 domain. In commands or code: dxos.network; the agent is likely to contact it when it follows the instructions. This is read from the text; nothing was executed.
Is Cloud Sandbox safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Cloud Sandbox use?
Cloud Sandbox has a licence file (the repository's licence) that doesn't match a standard licence. Read it on GitHub before reusing the skill.
How many tokens does Cloud Sandbox use?
About 3.9k tokens (SKILL.md is roughly 16k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Cloud Sandbox?
Skills that share tags, products or a category with Cloud Sandbox: Ckeditor5 Testing (TriliumNext/Trilium, 38k stars), Agent Integration Replay (Comfy-Org/ComfyUI_frontend, 2.1k stars), UI Preview (tingly-dev/tingly-box, 351 stars) and Tuistory (remorses/tuistory, 366 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Cloud Sandbox?
dxos (a GitHub organization) maintains it in dxos/dxos, which has 525 GitHub stars. The repository holds 41 skills in this directory. The repository was last updated on October 8, 2026.
Source: dxos/dxos on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.