Skill Creator: Create Custom Codex Skills
Official OpenAI guide for standardized Skill development
Do You Have These Problems?
This official OpenAI Skill helps standardize Skill development
How to create custom Codex Skills?
Follow standard structure: SKILL.md + scripts/ + references/ + assets/
What should a Skill contain?
Specialized workflows, tool integrations, domain knowledge, reusable scripts and resources
How to make Skills trigger efficiently?
Clearly describe functionality and trigger scenarios in description - it's the primary trigger mechanism
How to manage context for large Skills?
Use progressive loading: metadata β SKILL.md β load references on demand
Core Features
Complete Skill development toolchain
SKILL.md Template
Standardized YAML frontmatter + Markdown instruction structure
Resource Directory Spec
scripts/ for code, references/ for docs, assets/ for resources
Trigger Mechanism Design
Precisely control when Skill activates via description field
Progressive Loading
Three-level loading: metadata β body β on-demand resources
Validation & Packaging
Auto-validate structure and naming, generate .skill distribution package
Iterative Improvement
Continuously improve Skills based on real usage feedback
FAQ
- What are the core principles for Skills?
Concise is key. Context window is a public good - only add info Codex doesn't have. Challenge each piece: 'Does Codex really need this?'
- When to use scripts vs instructions?
High freedom tasks use text instructions, medium freedom uses pseudocode, low freedom (error-prone ops) uses specific scripts.
- How to organize large Skills?
Keep SKILL.md lean (<500 lines), split detailed content to references/ directory, load on demand.
- What are the naming conventions?
Use only lowercase letters, digits, and hyphens. Verb-led phrases, tool prefixes (e.g., gh-, notion-).