Skills: What They Are and How to Use Them

---
name: Skill name
description: Skill description
---

# Detailed description

Write detailed usage instructions and implementation logic here.

## Parameters

- `--param1`: Description of parameter 1
- `--param2`: Description of parameter 2

## Example

Example usage code

# Mac/Linux
mkdir -p ~/.codex/skills

# Windows (PowerShell)
New-Item -Path "$env:USERPROFILE\.codex\skills" -ItemType Directory -Force

mkdir ~/.codex/skills/codex-claude-skill-sync

name: codex-claude-skill-sync
description: Sync Codex and Claude Skills
---

# Codex/Claude Skill Sync

## Overview

Used to check and sync the Skill directories of Codex and Claude, keeping both sides consistent. By default, only reports differences; executes sync after user confirmation.

## Workflow

1. Run difference report (no modification):

   `python3 scripts/sync_skills.py`

2. Report differences to the user in English and wait for explicit consent before proceeding.
3. After consent, execute sync:

   `python3 scripts/sync_skills.py --apply`

4. When encountering a conflict (same modification time but different content), pause and ask the user which side to keep.

## Rules

- Default directories:
  - Codex: `/Users/yourusername/.codex/skills`
  - Claude: `/Users/yourusername/.claude/skills`
- Only process top-level directories that contain `SKILL.md`, skip hidden directories and `.system`
- Determine which side is newer based on the latest modification time in the directory
- When syncing, delete the target Skill directory first, then copy the entire source directory

## Parameters

- `--apply` Execute sync (default is report only)
- `--codex <path>` Override Codex directory
- `--claude <path>` Override Claude directory
- `--prefer codex|claude` When modification time is the same but content differs, use the specified side to overwrite (requires explicit user authorization)

mkdir ~/.codex/skills/codex-claude-skill-sync/scripts

#!/usr/bin/env python3
"""
Compare and sync skill folders between Codex and Claude.

Default behavior is report-only. Use --apply to perform sync.
"""

from __future__ import annotations

import argparse
import hashlib
import os
from datetime import datetime
from pathlib import Path
import shutil
import sys

DEFAULT_CODEX = Path("/Users/yourusername/.codex/skills")
DEFAULT_CLAUDE = Path("/Users/yourusername/.claude/skills")

IGNORE_DIR_NAMES = {".git", ".idea", ".vscode", "__pycache__", ".pytest_cache", ".mypy_cache"}
IGNORE_FILE_NAMES = {".DS_Store"}
TIME_EPSILON = 1.0


def format_time(timestamp: float) -> str:
    return datetime.fromtimestamp(timestamp).strftime("%Y-%m-%d %H:%M:%S")


def list_skill_dirs(root: Path) -> tuple[dict[str, Path], list[str]]:
    if not root.exists():
        raise FileNotFoundError(f"Root path does not exist: {root}")
    if not root.is_dir():
        raise NotADirectoryError(f"Root path is not a directory: {root}")

    skills: dict[str, Path] = {}
    ignored: list[str] = []
    for entry in sorted(root.iterdir(), key=lambda p: p.name):
        if not entry.is_dir():
            continue
        if entry.name.startswith("."):
            ignored.append(entry.name)
            continue
        if not (entry / "SKILL.md").is_file():
            continue
        skills[entry.name] = entry
    return skills, ignored


def dir_state(path: Path) -> tuple[str, float, int]:
    hasher = hashlib.sha256()
    latest_mtime = path.stat().st_mtime
    file_count = 0

    for root, dirs, files in os.walk(path):
        dirs[:] = [d for d in dirs if d not in IGNORE_DIR_NAMES]
        dirs.sort()
        files = sorted(f for f in files if f not in IGNORE_FILE_NAMES)

        rel_dir = os.path.relpath(root, path)
        if rel_dir == ".":
            rel_dir = ""
        hasher.update(f"D|{rel_dir}\n".encode())

        try:
            latest_mtime = max(latest_mtime, os.stat(root).st_mtime)
        except FileNotFoundError:
            continue

        for name in files:
            file_path = Path(root) / name
            rel_path = os.path.relpath(file_path, path)

            if file_path.is_symlink():
                try:
                    target = os.readlink(file_path)
                except OSError:
                    target = ""
                hasher.update(f"L|{rel_path}\n{target}\n".encode())
                try:
                    latest_mtime = max(latest_mtime, file_path.lstat().st_mtime)
                except FileNotFoundError:
                    pass
                continue

            if not file_path.is_file():
                continue

            stat = file_path.stat()
            latest_mtime = max(latest_mtime, stat.st_mtime)
            file_count += 1
            hasher.update(f"F|{rel_path}\n{stat.st_size}\n".encode())

            with open(file_path, "rb") as handle:
                for chunk in iter(lambda: handle.read(1024 * 1024), b""):
                    hasher.update(chunk)

    return hasher.hexdigest(), latest_mtime, file_count


def build_plan(
    codex_skills: dict[str, Path],
    claude_skills: dict[str, Path],
    codex_root: Path,
    claude_root: Path,
    prefer: str | None,
) -> tuple[list[dict], list[str], list[dict]]:
    actions: list[dict] = []
    identical: list[str] = []
    conflicts: list[dict] = []

    all_names = sorted(set(codex_skills) | set(claude_skills))
    for name in all_names:
        codex_path = codex_skills.get(name)
        claude_path = claude_skills.get(name)

        if codex_path and not claude_path:
            actions.append(
                {
                    "name": name,
                    "src": codex_path,
                    "dst": claude_root / name,
                    "reason": "only in codex",
                    "direction": "codex -> claude",
                }
            )
            continue
        if claude_path and not codex_path:
            actions.append(
                {
                    "name": name,
                    "src": claude_path,
                    "dst": codex_root / name,
                    "reason": "only in claude",
                    "direction": "claude -> codex",
                }
            )
            continue

        if not codex_path or not claude_path:
            continue

        codex_hash, codex_mtime, _ = dir_state(codex_path)
        claude_hash, claude_mtime, _ = dir_state(claude_path)

        if codex_hash == claude_hash:
            identical.append(name)
            continue

        time_delta = codex_mtime - claude_mtime
        if abs(time_delta) <= TIME_EPSILON:
            if prefer == "codex":
                actions.append(
                    {
                        "name": name,
                        "src": codex_path,
                        "dst": claude_path,
                        "reason": "same mtime, prefer codex",
                        "direction": "codex -> claude",
                        "codex_mtime": codex_mtime,
                        "claude_mtime": claude_mtime,
                    }
                )
            elif prefer == "claude":
                actions.append(
                    {
                        "name": name,
                        "src": claude_path,
                        "dst": codex_path,
                        "reason": "same mtime, prefer claude",
                        "direction": "claude -> codex",
                        "codex_mtime": codex_mtime,
                        "claude_mtime": claude_mtime,
                    }
                )
            else:
                conflicts.append(
                    {
                        "name": name,
                        "codex_mtime": codex_mtime,
                        "claude_mtime": claude_mtime,
                    }
                )
            continue

        if time_delta > 0:
            actions.append(
                {
                    "name": name,
                    "src": codex_path,
                    "dst": claude_path,
                    "reason": "codex newer",
                    "direction": "codex -> claude",
                    "codex_mtime": codex_mtime,
                    "claude_mtime": claude_mtime,
                }
            )
        else:
            actions.append(
                {
                    "name": name,
                    "src": claude_path,
                    "dst": codex_path,
                    "reason": "claude newer",
                    "direction": "claude -> codex",
                    "codex_mtime": codex_mtime,
                    "claude_mtime": claude_mtime,
                }
            )

    return actions, identical, conflicts


def print_report(
    actions: list[dict],
    identical: list[str],
    conflicts: list[dict],
    codex_root: Path,
    claude_root: Path,
    apply: bool,
    ignored_codex: list[str],
    ignored_claude: list[str],
) -> None:
    print("Skill sync report")
    print(f"Codex: {codex_root}")
    print(f"Claude: {claude_root}")

    if ignored_codex:
        print(f"Ignored in Codex: {', '.join(sorted(ignored_codex))}")
    if ignored_claude:
        print(f"Ignored in Claude: {', '.join(sorted(ignored_claude))}")

    print("\nPlanned sync actions:")
    if not actions:
        print("- none")
    else:
        for item in actions:
            codex_mtime = item.get("codex_mtime")
            claude_mtime = item.get("claude_mtime")
            details = []
            if codex_mtime is not None:
                details.append(f"codex mtime: {format_time(codex_mtime)}")
            if claude_mtime is not None:
                details.append(f"claude mtime: {format_time(claude_mtime)}")
            detail_text = f" ({', '.join(details)})" if details else ""
            print(f"- {item['name']}: {item['direction']} [{item['reason']}]" + detail_text)

    print("\nConflicts:")
    if not conflicts:
        print("- none")
    else:
        for item in conflicts:
            print(
                f"- {item['name']}: same mtime but different content "
                f"(codex {format_time(item['codex_mtime'])}, claude {format_time(item['claude_mtime'])})"
            )

    print(f"\nUp-to-date skills: {len(identical)}")

    if not apply:
        print("\nDry run only. Re-run with --apply to sync.")


def apply_actions(actions: list[dict]) -> None:
    for item in actions:
        src = Path(item["src"])
        dst = Path(item["dst"])

        if dst.exists():
            if dst.is_dir():
                shutil.rmtree(dst)
            else:
                dst.unlink()

        shutil.copytree(src, dst, symlinks=True)


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description="Sync Codex and Claude skill folders")
    parser.add_argument("--codex", type=Path, default=DEFAULT_CODEX, help="Codex skill root")
    parser.add_argument("--claude", type=Path, default=DEFAULT_CLAUDE, help="Claude skill root")
    parser.add_argument("--apply", action="store_true", help="Apply sync actions")
    parser.add_argument(
        "--prefer",
        choices=["codex", "claude"],
        help="Break ties when mtimes are equal",
    )
    return parser.parse_args()


def main() -> int:
    args = parse_args()

    try:
        codex_skills, ignored_codex = list_skill_dirs(args.codex)
        claude_skills, ignored_claude = list_skill_dirs(args.claude)
    except (FileNotFoundError, NotADirectoryError) as exc:
        print(str(exc), file=sys.stderr)
        return 2

    actions, identical, conflicts = build_plan(
        codex_skills,
        claude_skills,
        args.codex,
        args.claude,
        args.prefer,
    )
    print_report(
        actions,
        identical,
        conflicts,
        args.codex,
        args.claude,
        args.apply,
        ignored_codex,
        ignored_claude,
    )

    if args.apply and actions:
        apply_actions(actions)
        print("\nSync complete.")
    elif args.apply and not actions:
        print("\nNo changes to apply.")

    if conflicts and not args.prefer:
        return 1
    return 0


if __name__ == "__main__":
    raise SystemExit(main())

DEFAULT_CODEX = Path("/Users/yourusername/.codex/skills")
DEFAULT_CLAUDE = Path("/Users/yourusername/.claude/skills")

git clone https://github.com/your-team/skills.git ~/.codex/skills/team-skills