Codex skills

Codex skills are an important building block. They prevent Codex from treating all projects with the same reflexes.

Method skills

They frame how Codex works:

• diagnosis;
• planning;
• diff review;
• architecture;
• tests;
• lots;
• terminal output optimization;
• RepoMap maintenance.

Domain skills

A domain skill describes a domain and its critical rules. It must be operational for Codex:

• domain vocabulary;
• non-negotiable rules;
• sources of truth;
• likely LLM mistakes;
• expected patterns;
• anti-patterns;
• closure checklist.

Non-trivial business rules

When a task touches a business domain, Codex must use a relevant domain skill. If no skill exists, it must propose creating one instead of inventing rules.

Prompt to identify domain expertise

Analyze this project to identify critical business domains.

Do not code.

Read available documents, data models, screens, endpoints and existing rules.

Propose:
- DOMAIN_PROFILE;
- GLOSSARY;
- BUSINESS_RULES;
- RISK_REGISTER;
- HUMAN_VALIDATION_RULES;
- local domain skills plan.

Do not invent undocumented business rules. Mark assumptions.

Runtime skills

Runtime skills belong to application AI agents. They describe versioned behaviors loaded by runtime: careful diagnosis, support email writing, escalation, quality review, brand tone, and more.