Sandbox

Organization

rejot-dev

sandbox

Sandbox isolated shell work in Backoffice-managed Cloudflare containers. Use when the task requires starting, listing, executing commands in, or terminating a sandbox runtime.

Overview

Publisher	rejot-dev
Repository	`fragno`
Skill name	`sandbox`
Stars	62
Forks	6
Bundled files	Instructions only
License	MIT
Links	Skill source Repository Homepage

Markdown instructions
A SKILL.md file the model loads on demand, so it only costs tokens when a request actually matches.
Works with any LLM
AI skills are plain Markdown, not provider-specific code, so this works with GPT, Claude, Gemini, Grok, or a local model.
Self-contained
Everything the model needs lives in the instructions — no extra files to sync.
Open source
Published by rejot-dev on GitHub. Read the source before you install it.

Installation

Install the Sandbox AI skill in TypingMind to use it with any LLM, or drop it into another agent that reads SKILL.md.

Install in TypingMind

TypingMind installs a skill straight from its GitHub folder — it reads SKILL.md, bundles the resource files, and stores the result locally.

Open the app and go to Plugins → Skills.
Choose "Install from GitHub".
Paste the skill folder URL below and confirm.
Enable the skill in any chat where you want it available.

Store

Installed

Skills

Add skills

Import one or more skills from a public GitHub folder or a local .skill or .zip archive, or SKILL.md file.

From GitHub URLFrom .skill, .zip, or SKILL.md

GitHub repo or folder

https://github.com/rejot-dev/fragno/tree/main/apps/backoffice/content/static/skills/sandbox

Points to a single skill folder, or any folder that contains multiple skills. Public repos only.

CancelContinue

Plugins → Skills → Add skill → From GitHub URL, then paste the folder URL and press Continue.

Install in another agent

Any agent that reads the Agent Skills format can use this skill — copy the folder into that agent's skills directory.

Claude Code — .claude/skills

git clone --depth 1 https://github.com/rejot-dev/fragno.git /tmp/fragno
mkdir -p .claude/skills
cp -r /tmp/fragno/apps/backoffice/content/static/skills/sandbox .claude/skills/sandbox

Restart Claude Code after copying so it picks up the new skill.

Use it in TypingMind

Enable Sandbox in any TypingMind chat and the model takes it from there. Its name and description sit in the system prompt, and the moment a request matches, the model loads the full instructions itself — you never invoke it by hand, and it costs no tokens until it is actually used.

The model loads Sandbox on its own as soon as a request matches it.

Works with any AI model

AI skills are plain Markdown instructions rather than provider-specific code, so Sandbox is not tied to the model it was written for. Install it once in TypingMind and use it with GPT-5, Claude, Gemini, Grok, DeepSeek, Mistral, Llama, or a local model you run yourself — all on your own API keys.

Loaded only when it is needed
The system prompt carries just the name and description. The instructions are fetched on the first matching request, so an idle skill costs nothing.
Switch models mid-chat
Because the skill is instructions rather than code, changing model does not break it — the next model reads the same SKILL.md.

Skill instructions

This is the SKILL.md content the model loads. Read it before installing — a skill is instructions your model will follow.

Sandbox

Treat a sandbox as a leased environment: acquire → execute → release. The sandbox provider is available only when the deployment exposes the Sandbox capability.

Required process

Check for "/static/codemode/providers/sandbox.d.ts". If it is absent, report that this deployment does not expose the Sandbox capability. When present, read it and list current instances:
```
js
async () => await sandbox.listSandboxes({});
```
Reuse a suitable running sandbox or choose a stable id for a new one. Complete when the target sandbox id and lifecycle disposition are known.

Start a sandbox with an idle lease. Set keepAlive only when the user asks to preserve it beyond the task:

js
async () => {
  return await sandbox.startSandbox({
    id: "dev",
    sleepAfter: "15m",
    startupCommand: "true",
    startupTimeoutMs: 30000,
  });
};

Complete when the requested sandbox exists and its returned status has been checked.

Execute bounded commands and inspect the discriminated result:

js
async () => {
  const result = await sandbox.executeCommand({
    sandboxId: "dev",
    command: "pwd && ls -la",
    timeoutMs: 30000,
  });
  if (!result.ok) {
    throw new Error(result.reason + ": " + result.message);
  }
  return result;
};

Trust command output only when result.ok is true. On failure, use reason, retryable, stdout, and stderr to decide whether to correct the command, restart the sandbox, or report the failure. Complete when every command succeeded and its expected output was checked, or a non-retryable failure was identified precisely.

Release the lease when the task no longer needs the environment:

js
async () => await sandbox.killSandbox({ sandboxId: "dev" });

Complete only when the sandbox is killed, intentionally retained at the user's request, or left under an explicit sleepAfter lease.

Frequently asked questions

What does the Sandbox AI skill do?

Sandbox isolated shell work in Backoffice-managed Cloudflare containers. Use when the task requires starting, listing, executing commands in, or terminating a sandbox runtime.

Why use Sandbox on TypingMind?

Because you install it once and use it with any model. Sandbox is plain Markdown rather than provider-specific code, so the same skill runs on GPT-5, Claude, Gemini, Grok, or a local model — and you can switch model mid-chat without it breaking. TypingMind runs on your own API keys, so you pay providers directly instead of a per-seat subscription, and your skills and chats stay in your own storage.

How do I install Sandbox in TypingMind?

Open Plugins → Skills → Install from GitHub in TypingMind and paste https://github.com/rejot-dev/fragno/tree/main/apps/backoffice/content/static/skills/sandbox. TypingMind reads its SKILL.md and installs it as a skill you can enable per chat.

Which AI models can use Sandbox?

Any model you connect in TypingMind. AI skills are plain Markdown instructions rather than provider-specific code, so GPT, Claude, Gemini, Grok, and local models can all load this skill when a request matches it.

How many AI models can I use with Sandbox?

As many as you like. As long as a model supports skills, you can use Sandbox with it — GPT, Claude, Gemini, Grok, DeepSeek, Mistral, Llama and more — all on TypingMind with your own API keys.

Is the Sandbox AI skill free?

Yes. It is published on GitHub by rejot-dev under the MIT license. You only pay your own AI provider for the tokens you use.

What are AI skills?

An AI skill is a reusable instruction bundle that teaches an AI model how to do one specific task. It follows the open Agent Skills format: a SKILL.md file with a name and description, plus any scripts, templates or reference files the model may need. The model reads the instructions only when your request matches the skill, so an installed skill costs nothing until it is used.

How are AI skills different from plugins or MCP servers?

A plugin or MCP server gives a model new tools to call — code that runs somewhere and returns a result. An AI skill gives the model knowledge and process instead: how to approach a task, which steps to follow, what good output looks like. Skills are plain Markdown, so they need no server, no API key and no runtime, and they work with any model.

View all

Canary

garrytan

CommunityPopular

Post-deploy canary monitoring. (gstack)

Land And Deploy

Land and deploy workflow. (gstack)

Setup Deploy

Configure deployment settings for /land-and-deploy.

Caveman Compress

Compress a memory file such as CLAUDE.md or a todo list into caveman format to save input tokens, keeping a readable backup. Trigger: /caveman-compress.

Overview

Installation

Install in TypingMind

Install in another agent

Use it in TypingMind

Works with any AI model

Skill instructions

Sandbox

Required process

Frequently asked questions

Related AI Skills

Set up your own AI workspace now