DESIGN.md@crates/koyomiB
DESIGN.md@crates/koyomi from i2y/ritsu is a DESIGN.md file: the design rules coding agents follow in that repo.
mdr add i2y/ritsu/crates/koyomi/DESIGN.md@git:20261107.d281d9cPins git:20261107.d281d9c in mdr.lock. Pin the fingerprint instead.
- Audit grade
- B, 13 of 14 checks passed
- Kind
- DESIGN.md file
- Repository
- i2y/ritsu
- Path
crates/koyomi/DESIGN.md- Versions recorded
- 15
- Latest version
- git:20261107.d281d9c, committed Nov 7, 2026
- First version recorded
- Oct 23, 2026
- Size
- 249,274 bytes
- Repository stars
- 3
- License
- Apache-2.0
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# koyomi 設計文書
締めと支払、営業日、月の足し算を書く小さな言語。ファイルは `.cal`、コマンドは `koyomi`。書いた条件を範囲のすべての日について総当たりで確かめ、条件を満たさない日付をそのまま出す。検査を通ったものだけを、TypeScript・Python・Go・Rust・SQL（PostgreSQL）のコードと、どのホストからも呼べる Wasm のモジュールにする。
名前は暦（こよみ）から取った。
この文書は設計の段階（A）で書き、言語の芯を作った段階（B）、出力先を作った段階（C）、人が読むページと文書を作った段階（D）で直した。B で作ったのは、字句と構文、名前と型、カレンダー、参照インタプリタ、検査、診断、`check`・`eval`・`explain`・`api` のコマンドである。C で作ったのは、五つの出力先の生成（`gen`）、`vectors`、生成したコードと参照インタプリタの突き合わせ、`source fetch`・`pin`・`outdated` である。D で作ったのは、`doc`（7 章）、例の仕上げと英語の版（10 章）、`docs/`、README.md と README.ja.md、エージェント向けのスキル（`skills/koyomi`）、THIRD_PARTY_NOTICES.md である。3〜10 章に載せた出力とコードは、その段階の koyomi が実際に出したものに差し替えた。そのあと ritsu に移ってから、例とテストの材料を英語を先にした（England and Wales の例、日本の暦の例の英語の版、英語の名前のテストの材料と変異を足し、日本語のものは日本語の版として残した。10.1）。
文書に出てくる日付と日数は、A の段階で、使い捨ての試作（Python）が内閣府と GOV.UK の祝日の表から計算したものである。B の参照インタプリタが同じ数を出すことを、`tests/check.rs` が確かめている（一つも食い違わなかった）。
## 0. 全体像
```
.cal ── 字句・構文 ── 名前と型 ── カレンダー（出典のコピーを読む。通信しない）
│
├── 参照インタプリタ（意味を決める。計算の段を残す）
│ ├── check：範囲のすべての入力で、条件・無い日・データの範囲・例を確かめる
…Read the whole file at its exact version.
How to install
mdr add i2y/ritsu/crates/koyomi/DESIGN.md@sha256:806bb5926f4837f8The line at the top of this page pins the label git:20261107.d281d9c, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_lrwpto3pr62g2ibk)
1 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 15 versions of this file, between Oct 23, 2026 and Nov 7, 2026, about one every day.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261107.d281d9c latest | 2026-11-07 | d281d9c | 249,274 B | B | view · diff |
| git:20261105.96824a3 | 2026-11-05 | 96824a3 | 249,274 B | B | view · diff |
| git:20261105.0367349 | 2026-11-05 | 0367349 | 249,274 B | B | view · diff |
| git:20261105.fbcb5b7 | 2026-11-05 | fbcb5b7 | 249,274 B | B | view · diff |
| git:20261104.569f2ab | 2026-11-04 | 569f2ab | 248,491 B | B | view · diff |
| git:20261031.fbfaec0 | 2026-10-31 | fbfaec0 | 202,398 B | B | view · diff |
| git:20261031.76f9a81 | 2026-10-31 | 76f9a81 | 202,398 B | B | view · diff |
| git:20261031.d968c43 | 2026-10-31 | d968c43 | 200,962 B | B | view · diff |
| git:20261030.ebf5a2c | 2026-10-30 | ebf5a2c | 200,959 B | B | view · diff |
| git:20261030.99af105 | 2026-10-30 | 99af105 | 200,959 B | B | view · diff |
| git:20261029.1216bf8 | 2026-10-29 | 1216bf8 | 200,959 B | B | view · diff |
| git:20261029.200ec28 | 2026-10-29 | 200ec28 | 200,959 B | B | view · diff |
| git:20261029.9716f08 | 2026-10-29 | 9716f08 | 201,236 B | B | view · diff |
| git:20261023.0e181f9 | 2026-10-23 | 0e181f9 | 200,783 B | B | view · diff |
| git:20261023.b7ea664 | 2026-10-23 | b7ea664 | 200,783 B | B | view |
Audit of the latest version
- fail: Size between 200 bytes and 200 KB (249274 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Starting a new one? Use a template for DESIGN.md on mdpantry, which passes every one of these checks and says what to change in it.
Source
i2y/ritsu · 3 stars · license Apache-2.0 · pushed 2026-11-07 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_lrwpto3pr62g2ibk GET https://markdownregistry.com/api/v1/resolve?ref=i2y/ritsu/crates/koyomi/DESIGN.md GET https://markdownregistry.com/api/v1/blob/806bb5926f4837f8032614c257504fb98c2807e375a62b2dc5fa96784b5b0296
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: what DESIGN.md is and how agents use it · which agent file does what.