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Codex-native skill creator. Self-contained 4-phase methodology for creating production-ready Claude Code skills. Adapted from SkillCreator v3.2 for Codex agents with embedded methodology and simulated synthesis panel.

Install Skill

1Download skill
2Enable skills in Claude

Open claude.ai/settings/capabilities and find the "Skills" section

3Upload to Claude

Click "Upload skill" and select the downloaded ZIP file

Note: Please verify skill by going through its instructions before using it.

SKILL.md

name skillcreator-codex
description Codex-native skill creator. Self-contained 4-phase methodology for creating production-ready Claude Code skills. Adapted from SkillCreator v3.2 for Codex agents with embedded methodology and simulated synthesis panel.
license MIT
metadata [object Object]

SkillCreator for Codex

Create production-ready Claude Code skills using a systematic 4-phase methodology.

This skill is self-contained. All methodology is embedded below - no external file reads required.


Quick Start

Include this document in your Codex prompt, then add your request:

[This SKILL.md content]

---

Create a skill for: <your goal>

Constraints:
- <constraint 1>
- <constraint 2>

Context:
- Repo: <repo path>
- Related skills: <existing skills>

Output Location

All generated skills MUST go to the staging area:

tools/skills/generated/<skill_name>/

Structure:

tools/skills/generated/<skill_name>/
├── SKILL.md                    # Required - main entry point
├── SKILL_SPEC.md               # Recommended - specification document
├── references/                 # Optional - deep documentation
│   └── *.md
└── scripts/                    # Optional - automation scripts
    └── *.py

DO NOT output directly to .claude/skills/ - always use staging.


The 4-Phase Process

Your Request
    │
    ▼
┌─────────────────────────────────────────────────────┐
│ PHASE 1: DEEP ANALYSIS                              │
│ • Expand requirements (explicit, implicit, unknown) │
│ • Apply 11 thinking lenses                          │
│ • Regression questioning until exhausted            │
│ • Identify automation opportunities                 │
├─────────────────────────────────────────────────────┤
│ PHASE 2: SPECIFICATION                              │
│ • Document all decisions with rationale (WHY)       │
│ • Score evolution/timelessness (must be ≥7/10)      │
│ • Define success criteria                           │
├─────────────────────────────────────────────────────┤
│ PHASE 3: GENERATION                                 │
│ • Write SKILL.md with proper frontmatter            │
│ • Create references/ if needed                      │
│ • Create scripts/ if agentic                        │
├─────────────────────────────────────────────────────┤
│ PHASE 4: SYNTHESIS REVIEW                           │
│ • Self-review from 3 perspectives                   │
│ • All perspectives must approve                     │
│ • If issues found → loop back to Phase 1            │
└─────────────────────────────────────────────────────┘
    │
    ▼
Production-Ready Skill in tools/skills/generated/

PHASE 1: Deep Analysis

1A: Input Expansion

Transform the goal into comprehensive requirements:

Category Questions to Answer
Explicit What did the user literally ask for?
Implicit What do they expect but didn't say?
Unknown What don't they know they need?
Context What existing skills/patterns are related?

1B: 11 Thinking Lenses

Apply ALL of these lenses to the problem:

Lens Core Question
First Principles What's fundamentally needed? Strip away conventions.
Inversion What would guarantee failure? Build anti-patterns.
Second-Order What happens after the obvious effect?
Pre-Mortem Assume it failed - why?
Systems Thinking How do parts interact? Dependencies?
Devil's Advocate Strongest counter-argument?
Constraints What's truly fixed vs assumed?
Pareto Which 20% delivers 80% of value?
Root Cause Why is this needed? (5 Whys)
Comparative How do alternatives compare?
Opportunity Cost What are we giving up?

Requirement: Scan all 11, apply at least 5 in depth.

1C: Regression Questioning

Ask these questions in rounds until 3 consecutive rounds yield no new insights:

Round N:

  1. What am I missing?
  2. What would a domain expert add?
  3. What would make this fail?
  4. What will this look like in 2 years?
  5. What's the weakest part of this design?
  6. Which thinking lens haven't I applied?

Termination: Stop when 3 consecutive rounds produce no new insights.

1D: Automation Analysis

For each operation the skill will perform:

Question If YES →
Is this operation repeatable? Consider generation script
Does this produce verifiable output? Consider validation script
Does this need state across sessions? Consider state management
Can success be verified autonomously? Add self-verification

PHASE 2: Specification

Document your analysis in this structure:

# SKILL_SPEC.md

## Metadata
- **Name:** skill-name (hyphen-case)
- **Timelessness Score:** X/10 (must be ≥7)
- **Analysis Iterations:** N rounds

## Problem Statement
[What + Why + Who]

## Requirements

### Explicit
- [What user asked for]

### Implicit
- [Expected but unstated]

### Discovered
- [Found through analysis]

## Architecture
- **Pattern:** [Single-Phase | Checklist | Generator | Multi-Phase]
- **Phases:** [Ordered steps with verification]
- **Decision Points:** [Branches and defaults]

## Scripts (if applicable)
- **Needs Scripts:** Yes/No
- **Script Inventory:** [name, purpose, patterns]

## Evolution Analysis
- **Timelessness Score:** X/10
- **Justification:** [Why this score]
- **Extension Points:** [Where skill can grow]
- **Obsolescence Triggers:** [What would break it]

## Anti-Patterns
| Avoid | Why | Instead |
|-------|-----|---------|

## Success Criteria
- [ ] [Measurable criterion 1]
- [ ] [Measurable criterion 2]

Timelessness Scoring Guide

Score Description Verdict
1-3 Transient, will be obsolete in months Reject
4-6 Moderate, depends on current tooling Revise
7-8 Solid, principle-based, extensible Approve
9-10 Timeless, addresses fundamental problem Exemplary

Requirement: Score must be ≥7 to proceed.


PHASE 3: Generation

3A: Create Directory Structure

mkdir -p tools/skills/generated/<skill_name>/references
mkdir -p tools/skills/generated/<skill_name>/scripts  # if needed

3B: Write SKILL.md

Required frontmatter properties:

---
name: skill-name          # Required: hyphen-case, max 64 chars
description: "..."        # Required: max 1024 chars, no < or >
license: MIT              # Optional
metadata:                 # Optional
  version: 1.0.0
  domains: [...]
---

Required sections:

  1. Title - Clear name
  2. Quick Start - Immediate usage example
  3. Triggers - 3-5 varied invocation phrases
  4. Quick Reference - Table of inputs/outputs
  5. How It Works - Process overview
  6. Commands - Available commands
  7. Validation - How to verify success
  8. Anti-Patterns - What to avoid

3C: Create Scripts (if applicable)

Scripts must follow this pattern:

#!/usr/bin/env python3
"""
Script description.

Usage:
    python script_name.py <args>

Exit Codes:
    0  - Success
    1  - General failure
    10 - Validation failure
    11 - Verification failure
"""

import argparse
import sys
from dataclasses import dataclass
from typing import Optional

@dataclass
class Result:
    success: bool
    message: str
    data: Optional[dict] = None

def main() -> int:
    parser = argparse.ArgumentParser(description=__doc__)
    # Add arguments
    args = parser.parse_args()

    # Implementation
    result = do_work(args)

    if result.success:
        print(f"SUCCESS: {result.message}")
        return 0
    else:
        print(f"FAILURE: {result.message}", file=sys.stderr)
        return 1

if __name__ == "__main__":
    sys.exit(main())

PHASE 4: Synthesis Review

Since Codex cannot spawn subagents, perform self-review from these 3 perspectives:

Perspective 1: Design/Architecture Agent

Criterion Check
Pattern appropriate? Does the architecture match the problem?
Phases logical? Are steps in correct order with clear transitions?
No circular dependencies? Can each phase complete independently?
Error handling? Are failure modes addressed?

Score (1-10): ___ Verdict: APPROVED / CHANGES_REQUIRED

Perspective 2: Usability Agent

Criterion Check
Triggers natural? Would a user think to say this?
Steps unambiguous? Can someone follow without guessing?
No assumed knowledge? Is everything explained?
Quick start works? Can someone use it immediately?

Score (1-10): ___ Verdict: APPROVED / CHANGES_REQUIRED

Perspective 3: Evolution Agent

Criterion Check
Timelessness ≥7? Will this be useful in 2 years?
Extension points clear? Can it grow without rewrite?
Ecosystem fit? Does it complement existing skills?
WHY documented? Can someone understand the reasoning?

Score (1-10): ___ Verdict: APPROVED / CHANGES_REQUIRED

Consensus

IF all 3 perspectives APPROVED:
    → Finalize skill
    → Write to tools/skills/generated/<skill_name>/
    → Report completion

ELSE:
    → List all issues
    → Return to Phase 1 with issues as input
    → Re-analyze and regenerate
    → Re-review (max 3 iterations)

Validation Checklist

Before declaring complete:

  • SKILL.md exists with valid YAML frontmatter
  • Name is hyphen-case, ≤64 chars
  • Description ≤1024 chars, no < or >
  • 3-5 trigger phrases defined
  • Timelessness score ≥7 documented
  • All 3 synthesis perspectives approved
  • Output is in tools/skills/generated/ (not .claude/skills/)
  • SKILL_SPEC.md documents the analysis

Anti-Patterns (DO NOT DO)

Avoid Why Instead
Skip Deep Analysis Leads to shallow skills Complete all 11 lenses
No specification Can't verify decisions Write SKILL_SPEC.md
Output to .claude/skills/ Bypasses review Use staging area
Single trigger phrase Hard to discover 3-5 varied phrases
No verification criteria Can't confirm success Measurable outcomes
Missing WHY Can't evolve or debug Document rationale
Improvise when stuck Leads to drift STOP and report blocker

Failure Handling

If you cannot complete a step:

  1. STOP immediately - do not proceed
  2. Report exactly what is blocking:
    • Which phase/step
    • What information is missing
    • What error occurred
  3. Do not improvise a workaround
  4. Ask for clarification before continuing

Architecture Patterns

Select based on task complexity:

Pattern Use When Structure
Single-Phase Simple linear tasks Steps 1-2-3
Checklist Quality/compliance audits Item verification
Generator Creating artifacts Input → Transform → Output
Multi-Phase Complex ordered workflows Phase 1 → Phase 2 → Phase 3

Selection Decision Tree

Is it a simple procedure?
├── Yes → Single-Phase
└── No → Does it produce artifacts?
    ├── Yes → Generator
    └── No → Does it verify/audit?
        ├── Yes → Checklist
        └── No → Multi-Phase

Example Output Structure

For a skill named api-debugger:

tools/skills/generated/api-debugger/
├── SKILL.md
│   ---
│   name: api-debugger
│   description: "Debug API response times and identify bottlenecks."
│   license: MIT
│   metadata:
│     version: 1.0.0
│     domains: [api, debugging, performance]
│   ---
│   # API Debugger
│   [Content...]
│
├── SKILL_SPEC.md
│   # Specification
│   - Timelessness: 8/10
│   - Analysis rounds: 4
│   [Analysis documentation...]
│
├── references/
│   └── patterns.md
│
└── scripts/
    └── analyze_timing.py

After Generation

Once the skill is in tools/skills/generated/:

  1. Validate (if validation script available):

    python .claude/skills/skillcreator/scripts/quick_validate.py tools/skills/generated/<skill_name>
    
  2. Review the generated files manually

  3. Promote to active skills (after review):

    cp -r tools/skills/generated/<skill_name> .claude/skills/<skill_name>
    

Reference

  • Based on: SkillCreator v3.2
  • Upstream: tripleyak/skill-creator-and-improver @ 3dc5ed4
  • Claude Code version: .claude/skills/skillcreator/
  • This adaptation: Optimized for Codex with embedded methodology