check-env

check-env is a skill for Claude Code from ao92265/claude-code-playbook. It costs 89 tokens per session (498 once invoked), scanned A, original, MIT.

A pre-flight checklist for checking whether a development environment is ready, including tools, configuration files, ports, containers, and repository status.

In plain words
What is it for?
Use it before beginning development to check Docker, Node.js, package tools, environment files, occupied ports, Git status, remote access, and available memory.
Why use it?
It exposes setup problems that could block development or cause conflicts before you start a server or build.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the playbook plugin — 48 skills, 4 hooks shipped together

Good fit Use it before beginning development to check Docker, Node.js, package tools, environment…

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/ao92265/claude-code-playbook/check-env
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add ao92265/claude-code-playbook --skill check-env
Clone the repo
git clone --depth 1 https://github.com/ao92265/claude-code-playbook

Made for: Claude Code.

Or install playbook, the plugin that ships this one along with the rest of its 48 skills, 4 hooks.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for check-env

README.md
[![agentmods](https://agentmods.dev/badge/skills/ao92265/claude-code-playbook/check-env.svg)](https://agentmods.dev/skills/ao92265/claude-code-playbook/check-env)
Your own site
<a href="https://agentmods.dev/skills/ao92265/claude-code-playbook/check-env"><img src="https://agentmods.dev/badge/skills/ao92265/claude-code-playbook/check-env.svg" alt="Measured on agentmods" height="20"></a>
Per session 89 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 498 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00089 $0.00498
Opus 5 $0.00044 $0.00249
Sonnet 5 $0.00018 $0.00100
Haiku 4.5 $0.00009 $0.00050

Measured 7d ago against content hash 53a5ad42194a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

check-env scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/check-env/SKILL.md · 54 lines

What it actually says

Check Environment

Pre-flight environment check before starting dev work. Run this at the start of a session to avoid wasting time on infrastructure issues.

Steps

  1. Check for running Docker containers that might conflict:

    • docker ps to list running containers
    • Flag any containers using common ports (3000, 3001, 5432, 1433, 8080)
  2. Check for port conflicts on common dev ports:

    • lsof -i :3000,3001,5432,1433,8080 2>/dev/null to find processes using these ports
    • Report what's using each occupied port
  3. Verify environment files exist:

    • Check for .env or .env.local in the current project
    • Warn if missing but don't expose contents
  4. Check Docker daemon is running (if project uses Docker):

    • docker info > /dev/null 2>&1 to verify Docker is available
  5. Check Node.js and npm/yarn availability:

    • node --version and npm --version
  6. Verify git status and credentials:

    • git status to show current branch and any uncommitted changes
    • gh auth status to verify GitHub credentials work
    • Test push access: git ls-remote origin HEAD to confirm remote connectivity
  7. Check available memory for builds:

    • Report current Node.js version and default heap size
    • Recommend NODE_OPTIONS='--max-old-space-size=4096' if project has large builds
  8. Report a clean summary of findings with any issues flagged clearly.

Important

  • Do NOT start fixing issues automatically — report them and ask what to do
  • Do NOT expose .env file contents
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 7d ago First seen · 54 lines · 89 tokens per session scan A 53a5ad42194a

Subscribe to this mod's changes

check-env is a skill published in the GitHub repository ao92265/claude-code-playbook (10 stars, last pushed 20d ago), licensed MIT. It adds 89 tokens to every session and 498 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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