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Skill Host Compatibility Linter

Checks ECC skills for frontmatter and Claude-only substitutions that break in Codex or Cursor

Source Download skill
Repository
affaan-m/ECC
Stars
295,127
Licence
MIT
Files
2 files

What it does

This skill teaches an agent to run a compatibility check on skill files before they are submitted as a pull request to the ECC project. The check looks for Claude-specific variables (such as $CLAUDE_PROJECT_DIR) that Codex would leave as literal text, and for frontmatter fields that Codex copies should not contain. It also explains how to fix the findings, for example by rewriting variables to $(pwd). It is aimed at skill authors maintaining copies for Codex and Cursor, not at general Claude output quality.

Great for

  • Contributors to the ECC repository preparing a new or edited skill PR
  • Maintainers reviewing whether a skill is safe to copy into Codex or Cursor
  • Developers who see validate-skill-host-compat.js failures in CI and need to understand them

Skip it if

  • Users who only want to run a skill in Claude and have no Codex or Cursor copies (the checks do not affect Claude behaviour)
  • Projects outside ECC, since the script path and directory layout are specific to that repository and the files do not show it is portable
  • Anyone expecting a passing check to mean a skill is fully correct, because the SKILL.md itself warns that a passing validate-skills.js run is not proof of Codex safety

Try asking

  • “Check my new skill under skills/ before I open a PR”
  • “Why is validate-skill-host-compat.js reporting $CLAUDE_PROJECT_DIR in my Codex copy?”
  • “Show me the checklist warning count for the whole tree with --inventory”
  • “Which fields must I strip from the .agents/skills copy of this skill?”
Step-by-step guide: how to use Skill Host Compatibility LinterInstall, first run, examples, tips and FAQs

Install in 3 steps

  1. 1

    Download the skill

    The ZIP contains the 2 original files, the MIT licence and an attribution note.

    skill-host-compat.zip
  2. 2

    Add it to your agent

    Claude Code (all projects)

    mkdir -p ~/.claude/skills && unzip skill-host-compat.zip -d ~/.claude/skills/

    Claude Code / Agent SDK (this project only)

    mkdir -p .claude/skills && unzip skill-host-compat.zip -d .claude/skills/

    Claude apps (web/desktop): Settings → Capabilities → Skills → Upload skill, and choose the ZIP.

  3. 3

    Ask for the task

    No special command needed — the agent reads the skill's description and loads it when your request matches. Try one of the prompts above.

Get better results

  • Run the script from the repository root, and use --inventory first to see the volume of warnings without failing
  • Keep Claude-scoped variables in canonical skills/ copies and only resolve them in the Codex or Cursor copy
  • Use --strict-checklist only when you want checklist warnings to block your change

What's inside

  • agents/openai.yaml
  • SKILL.md

Redistributed unmodified from affaan-m/ECC under the MIT licence. The assessment was drafted with AI from the skill's files on 2026-10-29. Skills can instruct your agent to run code — read SKILL.md and any scripts before installing.