rules

Explain how Codex Rules discovers and injects project instructions into sessions.

5|Updated May 17, 2026
One-click install
npx skills add https://github.com/islee23520/lfg --skill rules-islee23520
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: rules
Source: https://github.com/islee23520/lfg/tree/main/skills/rules
Command: npx skills add https://github.com/islee23520/lfg --skill rules-islee23520

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This Skill explains how Codex Rules injects project guidance automatically, so users can understand where instructions come from and why certain file-specific rules appear during work.

Core Features & Use Cases

  • Rule Discovery: Identifies supported project instruction sources such as CONTEXT.md and multiple rules directories.
  • Injection Behavior: Describes when static instructions, file-specific matches, and dynamic post-tool context are added to a session.
  • Environment Configuration: Documents the available switches for disabling rules, changing injection modes, and limiting output size.
  • Use Case: A team can use this Skill to verify that their repository rules are being detected and injected the way they expect across Codex sessions.

Quick Start

Ask for a concise explanation of how Codex Rules discovers project instructions, injects them during a session, and which environment variables control that behavior.

Frequently Asked Questions about rules

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How does Codex Rules discover and inject project instructions into sessions?▼

Codex Rules discovers project instructions from documented sources like CONTEXT.md and rules directories, then injects static startup guidance, file-specific matches, and dynamic post-tool context into Codex sessions for consistent assistant behavior.

Can I configure environment variables to change Codex Rules injection behavior?▼

Yes, you can use environment configuration switches to disable rules, change injection modes, and limit output size, including applying legacy PI_RULES environment fallbacks for consistent project instructions.

What is dynamic post-tool context in Codex project instructions?▼

Dynamic post-tool context is project guidance injected during a Codex session after tool execution, allowing file-specific rules and instructions to appear dynamically based on the ongoing workflow and changes.

Does Codex Rules support legacy PI_RULES environment fallbacks?▼

Yes, Codex Rules requires support for legacy PI_RULES environment fallbacks, allowing repositories to maintain backward compatibility while detecting and injecting project instructions across Codex sessions.

Why are file-specific rules appearing during my Codex session?▼

File-specific rules appear during Codex sessions because Codex Rules matches and injects project instructions dynamically based on the files being worked on, ensuring relevant guidance is applied consistently.