Cross Platform Skill

Cross-Platform Skill Converter

Convert Claude Code skills and CLAUDE.md files to work across multiple AI coding assistants: Codex CLI (OpenAI) and Gemini CLI (Google).

Platform Instruction File Reference

All three use Markdown format with similar semantics, making conversion straightforward.

Conversion Workflow

Step 1: Analyze Source

Read the source skill/instruction file and identify:

• Core instructions (universal, work everywhere)
• Tool-specific references (Claude Code /commands, MCP configs, etc.)
• Platform-specific syntax or features

Step 2: Generate Platform Files

Run the conversion script to generate all platform variants:

python scripts/convert_skill.py <source-file> --output-dir <target-dir>

This creates:

• CLAUDE.md - Original or adapted for Claude Code
• AGENTS.md - Adapted for Codex CLI
• GEMINI.md - Adapted for Gemini CLI

Step 3: Handle Platform-Specific Features

Some features need adaptation:

Claude Code → Codex CLI:

• /project:command → Custom prompts in ~/.codex/prompts/
• .claude/commands/ → .codex/prompts/
• MCP in .mcp.json → MCP in ~/.codex/config.toml

Claude Code → Gemini CLI:

• /project:command → Custom commands in .gemini/commands/
• .claude/commands/ → .gemini/extensions/
• MCP in .mcp.json → MCP in .gemini/settings.json

Step 4: Choose Sync Strategy

Option A: Symlinks (recommended for personal use)

python scripts/setup_symlinks.py <canonical-file>

Option B: Copy with sync script (recommended for repos)

python scripts/create_sync_script.py <source-file> --output sync-instructions.sh

Option C: Git hook (auto-sync on commit)

python scripts/install_git_hook.py

Output Formats

Unified Skill Package

For distributing skills that work everywhere, create a package structure:

my-skill/
├── CLAUDE.md          # Claude Code version
├── AGENTS.md          # Codex CLI version  
├── GEMINI.md          # Gemini CLI version
├── instructions.md    # Canonical source (optional)
├── scripts/           # Shared scripts (work with all)
├── references/        # Shared reference docs
└── sync.sh           # Keeps files in sync

Repo-Level Instructions

For project repositories, add all three files at root:

my-project/
├── CLAUDE.md
├── AGENTS.md
├── GEMINI.md
└── ... (project files)

Compatibility Notes

Fully Compatible Features

• Markdown formatting and structure
• Code style guidelines
• Build/test commands
• Project structure documentation
• Coding conventions
• General workflow instructions

Platform-Specific Adaptations Needed

• Slash commands (different syntax per platform)
• MCP server configuration (different config files)
• Tool references (different built-in tools)
• Memory/context commands

Script Compatibility

Python and bash scripts in scripts/ directories generally work across all platforms since they execute in the shell. Only the instruction file format differs.

Quick Start Examples

Convert a CLAUDE.md to all platforms:

python scripts/convert_skill.py ./CLAUDE.md --output-dir ./

Set up symlinks from CLAUDE.md as canonical:

python scripts/setup_symlinks.py ./CLAUDE.md

Create a complete cross-platform skill package:

python scripts/package_cross_platform.py ./my-skill/ --output ./dist/