readme-sync - SKILL.md Agent Skill

name: readme-sync description: Keeps ccw-cli's two README files in sync — `README.md` (English, repo root) and `docs/README.ja.md` (Japanese). Whenever either file is edited, or the user asks for a README change without naming a file, this skill must fire and propagate the semantically equivalent change to the other file. Trigger on any edit touching `README.md` or `docs/README.ja.md`, and on any user request about "the README" (singular) since the siblings drift silently if you don't.

README Sync (ccw-cli)

This repo ships two README files that must stay in sync:

README.md — English, repo root, authoritative structure
docs/README.ja.md — Japanese translation, same structure, localized prose

When you edit one, always edit the other in the same change. Drifting siblings are the exact failure mode this skill exists to prevent.

When to fire

Any of these is enough:

An Edit/Write/MultiEdit targets README.md or docs/README.ja.md.
The user asks to update, translate, reword, add a section to, or fix something in "the README" without naming a file.
A diff being reviewed touches only one of the two.

Do not wait for the user to say "and update the other one." Treat "update the README" as "update both READMEs."

Workflow

Identify the source of truth — the file the user (or you) just modified. Everything else is a follow-up to the sibling.
Classify the change:
- Content change (wording, new section, version bump, link change, new bullet): propagate the semantic change into the sibling, matching its existing voice and terminology. Don't machine-translate mechanically — read the surrounding paragraph and keep its tone. Code blocks, shell commands, URLs, and badge markup stay byte-identical.
- Structural change (heading reorder, section added/removed, table row added): mirror the structure exactly. Heading text is localized; heading order and hierarchy match.
- Cosmetic/meta change (badge updates, anchor fixes, image paths, the 🇺🇸 English · 🇯🇵 日本語 switcher row): apply identically, adjusting only relative paths where siblings sit at different depths (README.md at root needs docs/README.ja.md; docs/README.ja.md needs ../README.md).
Preserve legitimate divergence. Japanese-specific phrasing, localized examples, or commentary that already differs between the files should stay as-is unless the change you're propagating directly affects it. Translate only the delta.
Keep the language switcher links correct. If a section move changes relative paths, verify both switcher rows still resolve:
- README.md → [🇺🇸 English](README.md) · [🇯🇵 日本語](docs/README.ja.md)
- docs/README.ja.md → [🇺🇸 English](../README.md) · [🇯🇵 日本語](README.ja.md)
Report what you synced in one or two sentences. The user can read the diff themselves.

Why this matters for ccw-cli

ccw-cli is distributed via Homebrew to a bilingual audience. A typo in the English "Requirements" section that never lands in Japanese means JP users install the wrong Claude Code version for months. A new -s flag documented only in Japanese means English readers never discover it. The individual miss is small; the cumulative effect is a docs pair that's untrustworthy in at least one language.

Anti-patterns

"I'll do the Japanese in a follow-up commit." You won't. Do it now.
Re-translating the whole paragraph when only one sentence changed. Touch only the delta — the user already carefully worded the rest.
Mechanically translating the English into Japanese ignoring existing terminology. Look at how docs/README.ja.md already phrases similar concepts and match that.
Copying code blocks with their English comments into the Japanese file when the existing Japanese file has localized comments inside the same block — keep the localized comments.
Touching the flag-emoji language switcher on every edit. Leave it alone unless a file moved.
Creating a third language file (e.g. README.zh.md) without being asked. Sync what exists.

Examples

Example 1: Version bump

README.md edit:

- Go >= 1.24
+ Go >= 1.25

Sync to docs/README.ja.md:

- Go >= 1.24
+ Go >= 1.25

(Surrounding Japanese prose is untouched.)

Example 2: New section

README.md appends:

## 🗺️ Roadmap

- Shell completion (bash / zsh)
- Windows support

docs/README.ja.md appends at the matching location:

## 🗺️ ロードマップ

- シェル補完 (bash / zsh)
- Windows サポート

Example 3: Link-only fix

Source swaps https://old/... → https://new/.... Sync: update the same URL in the sibling; do not retranslate surrounding prose.