Claude Skill MartBrowse skillsWhat is a Skill?
 
← Back to list

Codex Rules Reference

A reference skill explaining which project rule files Codex Rules injects and which environment variables control it.

Dev & CodingIntermediate★ 67,531⑂ 5,507AI score 5/10Last updated: Aug 9, 2026

What it does

A documentation-style skill so Claude can answer accurately about Codex Rules behavior.

  • Static project instructions injected on SessionStart and UserPromptSubmit
  • File-matched rules injected after Codex apply_patch (dynamic mode, deduplicated per session)
  • Supported sources: CONTEXT.md, .omo/rules/**/*.md, .claude/rules/**/*.md, .cursor/rules/**/*.md, .github/instructions/**/*.md, .github/copilot-instructions.md
  • Env knobs: CODEX_RULES_DISABLED, CODEX_RULES_MODE, CODEX_RULES_MAX_RULE_CHARS, CODEX_RULES_MAX_RESULT_CHARS, CODEX_RULES_ENABLED_SOURCES (legacy PI_RULES_* accepted)

Who it's for

  • Developers running the oh-my-openagent / omo-codex plugin
  • Teams sharing rule files across Claude, Cursor and Copilot in one repo
  • Users migrating away from pi-rules

Examples

  1. "Why aren't my project rules being injected?" → it walks through supported paths and the CODEX_RULES_MODE setting.
  2. "I only want static injection" → it shows how to set CODEX_RULES_MODE=static.
  3. "Limit reading to .cursor/rules only" → it explains configuring CODEX_RULES_ENABLED_SOURCES.

· · · Install guide · · ·

Install in the Claude app (no terminal)
  1. Download the ZIP with the button below.
  2. In Claude, open Settings → Capabilities and turn on 'Code execution and file creation'. (one time)
  3. Go to Customize → Skills → + → 'Upload a skill' and upload the ZIP.
↓ Download ZIP
Install in Claude Code

Let Claude do it — paste this into Claude Code

Install the skill I found on Claude Skill Mart.
Copy the packages/omo-codex/plugin/components/rules/skills/rules folder from the GitHub repo code-yeongyu/oh-my-openagent into my ~/.claude/skills/rules/.
When it's done, tell me in one line what this skill can do.

Install with a command instead

git clone https://github.com/code-yeongyu/oh-my-openagent.git && cp -r oh-my-openagent/packages/omo-codex/plugin/components/rules/skills/rules ~/.claude/skills/rules

⚠ This is a third-party skill. Check the source repository before installing.

  1. Open a terminal.
  2. Clone the repo: git clone https://github.com/code-yeongyu/oh-my-openagent.git
  3. Create the skills folder: mkdir -p ~/.claude/skills
  4. Copy the skill: cp -r oh-my-openagent/packages/omo-codex/plugin/components/rules/skills/rules ~/.claude/skills/rules
  5. Restart Claude Code.
  6. Ask something like "Which rule files does Codex Rules read?" to trigger it.
  7. (Optional) Install the omo-codex plugin itself if you want the actual rule-injection behavior.
View source on GitHub ↗License: NOASSERTION