Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add kazukinagata/shinkoku --skill invoice-systemgit clone --depth 1 https://github.com/kazukinagata/shinkokuWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/kazukinagata/shinkoku/invoice-system)<a href="https://agentmods.dev/skills/kazukinagata/shinkoku/invoice-system"><img src="https://agentmods.dev/badge/skills/kazukinagata/shinkoku/invoice-system/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/kazukinagata/shinkoku/invoice-system"><img src="https://agentmods.dev/badge/skills/kazukinagata/shinkoku/invoice-system.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00217 | $0.01837 |
| Opus 5 | $0.00109 | $0.00919 |
| Sonnet 5 | $0.00043 | $0.00367 |
| Haiku 4.5 | $0.00022 | $0.00184 |
Grade A, and why
invoice-system scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 12d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 118 lines — stays where its author put it; the contents beside it link to each section on GitHub.
インボイス制度（Invoice System）
適格請求書等保存方式（インボイス制度）に関する包括的な知識ベース。 制度の概要、記載要件、経過措置、仕入税額控除ルール、登録判断を支援する。
制度概要
インボイス制度（適格請求書等保存方式）は、令和5年（2023年）10月1日に開始された消費税の仕入税額控除に関する制度。課税事業者が仕入税額控除を受けるためには、原則として「適格請求書発行事業者」が発行する「適格請求書（インボイス）」の保存が必要となる。適格請求書発行事業者になるには税務署への登録申請が必要で、登録番号（T+13桁）が付与される。
令和8年度税制改正大綱（R7.12.26閣議決定）により、3割特例の新設、経過措置スケジュールの5段階化など大幅な変更がある。
クイックリファレンス
登録番号の形式
- T + 13桁の数字
- 法人: T + 法人番号（例: T1234567890123）
- 個人: T + 固有番号（マイナンバーとは異なる）
適格請求書の6つの必須記載事項
- 発行事業者の氏名又は名称及び登録番号
- 取引年月日
- 取引内容（軽減税率対象品目の明示含む）
- 税率ごとに区分した対価の額及び適用税率
- 税率ごとに区分した消費税額等
- 受領者の氏名又は名称
現行の経過措置一覧（令和7年時点）
| 措置 | 内容 | 適用期限 |
|---|---|---|
| 2割特例 | 売上消費税額の20%を納付 | R8.9.30を含む課税期間まで |
| 免税事業者仕入控除 | 80%→70%→50%→30%→0% | R11.10.1で完全移行 |
| 少額特例 | 税込1万円未満はインボイス不要 | R11.9.30まで |
| 少額返還インボイス免除 | 税込1万円未満は返還インボイス不要 | 恒久措置 |
消費税額の端数処理
- 1インボイスにつき、税率ごとに1回の端数処理
- 切捨て・切上げ・四捨五入いずれも可（事業者の選択）
- 行ごとの端数処理は不可
リファレンスファイル参照ガイド
質問の内容に応じて、以下のリファレンスファイルを参照する:
| 質問カテゴリ | 参照ファイル |
|---|---|
| 適格請求書の記載事項・種類・端数処理 | references/qualified-invoice-requirements.md |
| 経過措置のスケジュール・控除率・期限 | references/transitional-measures-timeline.md |
| 仕入税額控除の要件・例外・保存ルール | /tax-invoice-credit-context を実行する |
| 登録すべきか・計算方法の選択 | references/decision-flowchart.md |
| 実務上のよくある間違い・注意点 | references/common-pitfalls.md |
| 登録申請・取消手続き・基準期間 | references/registration-procedures.md |
| BtoC事業者の判断・価格戦略 | references/btoc-and-pricing-strategy.md |
| その他の質問・特定状況 | references/faq.md |
回答パターン
ユーザーの質問に回答する際は、以下の構造に従う:
1. 結論（Answer）
質問に対する明確な回答を最初に提示する。
2. 根拠（Legal Basis）
関連する法令・通達を示す。例:
- 「消費税法第57条の4に基づき、適格請求書の交付義務があります」
- 「R8大綱により、R9年分から3割特例が新設されます（個人事業主のみ）」
3. 計算例（Calculation Example）
該当する場合は具体的な数値例を示す。金額は int（円単位の整数）で、端数処理ルール（CLAUDE.md 記載）に従う。
4. 注意点（Caveats）
- 落とし穴や例外事項を指摘する
references/common-pitfalls.mdの該当項目を参照
5. 免責事項（Disclaimer）
回答の末尾に以下を付記する:
この情報は一般的な税法の解釈に基づくものであり、個別の状況により異なる場合があります。具体的な判断は税理士等の専門家にご相談ください。
他スキルとのクロスリファレンス
What ships with it
7 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 12d ago First seen · 118 lines · 217 tokens per session scan A 139a310e2d7e
invoice-system is a skill published in the GitHub repository kazukinagata/shinkoku (359 stars, last pushed 3d ago), licensed MIT. It adds 217 tokens to every session and 1,837 once invoked, about $0.0011 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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