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Dev Server Sandbox

Checked
coder·vlatest·backend·AGPL-3.0

Quickly spins up isolated development servers & sandboxes for testing code changes without impacting production environments.

Repository

Install on your platform

Showing Claude Code. One command installs this skill into any of the agents below.

  1. 1

    Run this in your project

    terminal
    $ npx skills add coder/xum --skill dev-server-sandbox --full-depth -a claude-code

  2. Uses the open-source skills CLI and needs Node.js. Add -g to install it for your user instead of this project.

What we know about this skill

Publisher

coder

Taken from the source listing. We haven't verified who controls this account.

Install target

Live repository

Not pinned. Installing fetches whatever the repository holds at the time you run the command.

No human has reviewed this code. The checks below are a static scan of the files at one commit — nobody has run this skill or judged whether it works. A skill runs with whatever access you give your agent, so read the source before you install it.

Automated safety checks

scanned

This skill passed all 6 checks. We read its files at one commit and looked for the things that make a skill dangerous to run — not for whether it works.

  • Declares what it does: passed

    SKILL.md parses and declares a name and a description.

    SKILL.md exists, its frontmatter parses, and it declares a name and a description.

  • No undeclared network calls: passed

    Makes no network calls.

    Every host the skill dials — from its scripts, its config endpoints or the commands it tells the agent to run — is either well-known package and API infrastructure or declared in its own frontmatter. Links in documentation are not counted.

  • No obfuscated payloads: passed

    No encoded or obfuscated payloads.

    No base64, hex or compressed blob is decoded and then executed, and no encoded shell commands.

  • No credential access: passed

    Reads no keys, tokens, keychains or credential files.

    Neither the code nor the SKILL.md instructions read SSH keys, cloud credentials, keychains, token stores, browser cookie databases or dotfiles that hold secrets.

  • No pipe-to-shell installers: passed

    No pipe-to-shell or download-and-run installers.

    No `curl … | sh` pattern, in the code or in the instructions, that runs code fetched at run time.

  • Pinned to a commit: passed

    Scanned coder/mux at 54082e00e3.

    The exact upstream commit SHA that was scanned is recorded, so the result refers to specific bytes.

Commit
54082e00e3
Manifest
.xum/skills/dev-server-sandbox/SKILL.md
Scanned
1 file, 91 lines
This is a static scan, not a review. It reads the skill's files; it does not run them, and it cannot tell you whether the skill is any good or whether the code does what its description says. A skill runs with whatever access you give your agent.
What each check looks for →

About this skill

What it does

The dev-server-sandbox skill provides a local development server environment. It allows you to quickly spin up isolated environments for testing and experimentation, preventing conflicts with existing projects or system configurations. This is particularly useful when needing to test code changes in a controlled setting without affecting the broader system.

When to use it

  • Testing new libraries: Quickly evaluate a new JavaScript library without impacting your main project's dependencies.
  • Reproducing bugs: Create a minimal, reproducible environment to isolate and debug issues.
  • Experimenting with configurations: Safely test different server configurations (e.g., port numbers, middleware) in an isolated space.
  • Developing local tools: Build and test custom development tools without interfering with existing projects.

Key capabilities

  • Local development server creation
  • Isolated environment for testing
  • Dependency management within the sandbox
  • Configuration control

Example prompts

  • "Create a dev server sandbox using Node 18."
  • "Start a local development server with Express and CORS enabled."
  • “Set up a dev-server-sandbox with React and TypeScript.”

Tips & gotchas

The skill requires Node.js to be installed on your system. Be mindful of the resources used by the sandbox environment, as running multiple sandboxes simultaneously can impact performance.