Markdown Article Formatter
JimLiu/baoyu-skills
Reformats plain text or Markdown articles with frontmatter, a title, a summary, headings, bold, lists and code blocks, and saves a separate formatted copy.
Evaluate a math formula without eval in a Code node or CodeAct action, with expr-eval running on the host
Install Sandbox Expr
$ npx skills add nodetool-ai/nodetool --skill sandbox-expr -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install nodetool-ai/nodetool sandbox-expr --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/nodetool-ai/nodetool.git skills-src && mkdir -p .claude/skills && cp -r skills-src/packages/sandbox-packs/sandbox-expr .claude/skills/sandbox-expr && 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 "sandbox-expr" agent skill from https://github.com/nodetool-ai/nodetool/tree/main/packages/sandbox-packs/sandbox-expr into .claude/skills/sandbox-expr/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "sandbox-expr", 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/nodetool-ai/nodetool/tree/main/packages/sandbox-packs/sandbox-exprType 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 nodetool-ai/nodetool --skill sandbox-expr -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install nodetool-ai/nodetool sandbox-expr --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/nodetool-ai/nodetool.git skills-src && mkdir -p .agents/skills && cp -r skills-src/packages/sandbox-packs/sandbox-expr .agents/skills/sandbox-expr && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "sandbox-expr" agent skill from https://github.com/nodetool-ai/nodetool/tree/main/packages/sandbox-packs/sandbox-expr into .agents/skills/sandbox-expr/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "sandbox-expr", 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 nodetool-ai/nodetool --skill sandbox-expr -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install nodetool-ai/nodetool sandbox-expr --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/nodetool-ai/nodetool.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/packages/sandbox-packs/sandbox-expr .cursor/skills/sandbox-expr && 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 "sandbox-expr" agent skill from https://github.com/nodetool-ai/nodetool/tree/main/packages/sandbox-packs/sandbox-expr into .cursor/skills/sandbox-expr/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "sandbox-expr", 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/nodetool-ai/nodetool.git --path packages/sandbox-packs/sandbox-expr--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 nodetool-ai/nodetool --skill sandbox-expr -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install nodetool-ai/nodetool sandbox-expr --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/nodetool-ai/nodetool.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/packages/sandbox-packs/sandbox-expr .gemini/skills/sandbox-expr && 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 "sandbox-expr" agent skill from https://github.com/nodetool-ai/nodetool/tree/main/packages/sandbox-packs/sandbox-expr into .gemini/skills/sandbox-expr/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "sandbox-expr", 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 nodetool-ai/nodetool sandbox-exprInstalls 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 nodetool-ai/nodetool --skill sandbox-expr -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/nodetool-ai/nodetool.git skills-src && mkdir -p .github/skills && cp -r skills-src/packages/sandbox-packs/sandbox-expr .github/skills/sandbox-expr && 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 "sandbox-expr" agent skill from https://github.com/nodetool-ai/nodetool/tree/main/packages/sandbox-packs/sandbox-expr into .github/skills/sandbox-expr/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "sandbox-expr", 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 nodetool-ai/nodetool --skill sandbox-expr -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install nodetool-ai/nodetool sandbox-expr --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/nodetool-ai/nodetool.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/packages/sandbox-packs/sandbox-expr .opencode/skills/sandbox-expr && 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 "sandbox-expr" agent skill from https://github.com/nodetool-ai/nodetool/tree/main/packages/sandbox-packs/sandbox-expr into .opencode/skills/sandbox-expr/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "sandbox-expr", 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
sandbox-expr- GitHub stars
- 556
- Token cost
- ~192 tokens
- SKILL.md length
- 70 words
- Files
- 2
- Skills in repo
- 127
- Repo updated
- First seen
- Licence
- AGPL-3.0
At a glance
Evaluate a math formula without eval in a Code node or CodeAct action, with expr-eval running on the host
- Documents & Office work in your project
- SKILL.md covers evaluate — formula plus… and Gotchas
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Sandbox Expr is an agent skill from nodetool-ai/nodetool. Evaluate a math formula without eval in a Code node or CodeAct action, with expr-eval running on the host
Its SKILL.md is about 190 tokens, which your agent loads only when the skill is triggered. The skill folder holds 1 other file (for example `package.json`).
It sits in Documents & Office. The repository describes itself as: Agent-first Creative Workspace. The licence is AGPL-3.0.
When your agent uses it
- Documents & Office work in your project
Example prompts
- “/sandbox-expr”
What it can do on your machine
Read from SKILL.md and the folder at commit 515bd28. 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
No scripts in the folder and no shell commands in SKILL.md (its code samples are javascript).
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
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
Sandbox Expr loads about 192 tokens when it runs. Until then it costs about 30 tokens; SKILL.md has 70 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
The full file from nodetool-ai/nodetool at commit 515bd28, republished under its AGPL-3.0 licence (© nodetool-ai). 70 words, ~192 tokens.
Download SKILL.mdSave it as
.claude/skills/sandbox-expr/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.- name
- sandbox-expr
- description
- Evaluate a math formula without eval in a Code node or CodeAct action, with expr-eval running on the host
Formulas in the sandbox
Specifier: @nodetool-ai/sandbox-expr. Import it at the top of the body.
The published expr-eval bundle trips the guest scanner, so this pack is a host module.
evaluate — formula plus variables
import { evaluate } from "@nodetool-ai/sandbox-expr";
const value = await evaluate(inputs.formula, inputs.vars);
return { value };inputs.formula is a string such as "2 * qty + fee". inputs.vars is
{ qty: 3, fee: 1.5 }.
Gotchas
- Not JavaScript.
^is power. Unknown names throw. - Do not use
eval. The guest deletes it. This pack is the formula path.
© nodetool-ai, AGPL-3.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
SKILL.md and 1 other file in packages/sandbox-packs/sandbox-expr of nodetool-ai/nodetool.
- SKILL.md
- package.json
Open the folder on GitHubat commit 515bd28
Compare with similar skills
Sandbox Expr 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 |
|---|---|---|---|---|---|---|
| Sandbox Expr this skillnodetool-ai/nodetool | 556 | — | ~192 | Automated safety check: Pass | AGPL-3.0 | |
| Markdown Article FormatterJimLiu/baoyu-skills | 26k | 7 repos | ~3.5k | Automated safety check: Pass | MIT | |
| MarkitdownImCa0/just-laws | 781 | 14 repos | ~3.2k | Automated safety check: Notes | MIT | |
| Obsidian MarkdownAtmosphere/atmosphere | 3.8k | 20 repos | ~1.3k | Automated safety check: Pass | Apache-2.0 | |
| DOCXrvdbreemen/OTGW-firmware | 207 | 33 repos | ~4.3k | Automated safety check: Pass | Proprietary | |
| Gzh Designisjiamu/gzh-design-skill | 3.9k | 1 repos | ~2.2k | Automated safety check: Pass | AGPL-3.0 |
Similar skills
Markitdown
ImCa0/just-laws
Convert files and office documents to Markdown. An agent skill from ImCa0/just-laws.
Obsidian Markdown
Atmosphere/atmosphere
Create and edit Obsidian Flavored Markdown with wikilinks, embeds, callouts, properties, and other Obsidian-specific syntax.
DOCX
rvdbreemen/OTGW-firmware
A skill your agent uses whenever the user wants to create, read, edit, or manipulate Word documents (.docx files).
Gzh Design
isjiamu/gzh-design-skill
微信公众号文章排版引擎，将 Markdown 转换为可直接粘贴到公众号编辑器的 HTML。主题风格从 references/theme-index.md 注册的自定义主题库中选取，自动章节编号、关键词下划线标记、引言卡片、目录导航、代码块、图片/GIF、作者签名。支持 Markdown / Word(.docx) / PDF / 纯文本输入（非 Markdown…
Word Document Reader and Writer
HKUDS/DeepTutor
Reads, creates and edits Word .docx files with python-docx, and drops to raw OOXML for tracked changes, comments and byte-exact edits.
More from nodetool-ai/nodetool
All 127 skills in this repoBeat Sync Editing
nodetool-ai/nodetool
Cut a NodeTool timeline to music and shape its pacing — detect the beat grid, place cuts on phrases, pick a cut type, build speed ramps with time remap, and give the piece an arc.
Caption Titles
nodetool-ai/nodetool
Add and animate a consistent text layer on an existing NodeTool timeline.
Color Motion
nodetool-ai/nodetool
Choose and animate colour on a NodeTool timeline, including shape and text gradients, colour grades, 3D LUTs, and dither.
Commercial Beat Sheet
nodetool-ai/nodetool
Write a shootable, precisely timed commercial beat sheet and store it as a NodeTool storyboard, with a consistent entity roster behind every shot.
Elevenlabs Audio Prompting
nodetool-ai/nodetool
Direct ElevenLabs speech, dialogue, sound effects and music — the bracketed audio tags v3 acts on and why the voice decides whether a tag lands, stability as the delivery dial, punctuation instead…
Frame Composition
nodetool-ai/nodetool
Stage the frame on a NodeTool timeline — grids, focal placement, safe areas per aspect ratio, depth layers and parallax, camera moves, and where elements enter and leave.
Related
Categories
Questions about Sandbox Expr
What does Sandbox Expr do?
Evaluate a math formula without eval in a Code node or CodeAct action, with expr-eval running on the host. Sandbox Expr is an agent skill from nodetool-ai/nodetool.
When should I use Sandbox Expr?
Sandbox Expr fits situations like: documents & Office work in your project.
How do I install Sandbox Expr in Claude Code?
Run `npx skills add nodetool-ai/nodetool --skill sandbox-expr -a claude-code`. Or copy the skill folder (packages/sandbox-packs/sandbox-expr in nodetool-ai/nodetool) into .claude/skills/sandbox-expr in your project. Claude Code loads it when a task matches its description.
How do I install Sandbox Expr in Codex?
Run `npx skills add nodetool-ai/nodetool --skill sandbox-expr -a codex`. Or copy the skill folder (packages/sandbox-packs/sandbox-expr in nodetool-ai/nodetool) into .agents/skills/sandbox-expr in your project. Codex loads it when a task matches its description.
Can I use Sandbox Expr 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 nodetool-ai/nodetool --skill sandbox-expr -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/sandbox-expr, .gemini/skills/sandbox-expr, .github/skills/sandbox-expr and .opencode/skills/sandbox-expr in your project.
What does Sandbox Expr need to run?
SKILL.md names no scripts, command-line tools or credentials: Sandbox Expr is instructions for the agent only.
Does Sandbox Expr access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Sandbox Expr 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 Sandbox Expr use?
Sandbox Expr is published under the AGPL-3.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Sandbox Expr use?
About 192 tokens (SKILL.md is roughly 768 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 Sandbox Expr?
Skills that share tags, products or a category with Sandbox Expr: Markdown Article Formatter (JimLiu/baoyu-skills, 26k stars), Markitdown (ImCa0/just-laws, 781 stars), Obsidian Markdown (Atmosphere/atmosphere, 3.8k stars) and DOCX (rvdbreemen/OTGW-firmware, 207 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Sandbox Expr?
nodetool-ai (a GitHub organization) maintains it in nodetool-ai/nodetool, which has 556 GitHub stars. The repository holds 127 skills in this directory. The repository was last updated on October 8, 2026.
Source: nodetool-ai/nodetool on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.