# Inspired by

lgtmaybe's review lenses distill widely-shared engineering wisdom and the
broader "skills / rules / review-prompt" ecosystem into focused, structured
lenses. This page credits those sources so the project can be an honest FOSS
one-stop shop rather than a silent re-implementation.

Two honesty notes up front:

- These are **concept attributions**. A lens is our own wording of an idea; it is
  not copied text. Where the idea comes from a book or essay (Ousterhout, Metz,
  Carmack) the source is the *concept*, not a review-skill file.
- A few sources below were **cross-checked across multiple references rather than
  fetched directly** (some hosts block automated fetches). Where we could not
  trace an idea to any specific published source, the lens is marked an **original
  synthesis** and cites no repo — we would rather say "ours" than invent a lineage.

## Built-in lens

| Lens | Idea / source | Where |
|---|---|---|
| `ponytail` | **Ponytail** — "the laziest senior dev in the room; the best code is the code you never wrote." | [DietrichGebert/ponytail](https://github.com/DietrichGebert/ponytail) |

## Bundled opt-in packs (`pack:design`, `pack:robustness`, `pack:interface`, `pack:frontend`)

| Lens | Idea / source | Where |
|---|---|---|
| `wrong-abstraction` | Sandi Metz — **"The Wrong Abstraction"** (duplication is cheaper than the wrong abstraction) and **Sandi Metz' Rules**. | [sandimetz.com](https://sandimetz.com/blog/2016/1/20/the-wrong-abstraction) · [thoughtbot](https://thoughtbot.com/blog/sandi-metz-rules-for-developers) |
| `shallow-module` | John Ousterhout — **A Philosophy of Software Design** (deep vs. shallow modules; pass-through methods; temporal decomposition). | [aposd (Stanford)](https://web.stanford.edu/~ouster/cgi-bin/aposd.php) |
| `information-leakage` | John Ousterhout — *A Philosophy of Software Design* (information leakage: one design decision known in two places). | [aposd (Stanford)](https://web.stanford.edu/~ouster/cgi-bin/aposd.php) |
| `errors-out-of-existence` | John Ousterhout — *A Philosophy of Software Design* ("define errors out of existence"). | [aposd (Stanford)](https://web.stanford.edu/~ouster/cgi-bin/aposd.php) |
| `hidden-state` | John Carmack — **"Inlined Code" / functional-style** argument (make all touched state explicit; mutation is the enemy). | [number-none.com](http://number-none.com/blow/blog/programming/2014/09/26/carmack-on-inlined-code.html) |
| `naming` | John Ousterhout — *A Philosophy of Software Design* (choosing names); the naming chapter of **Clean Code**. | [aposd (Stanford)](https://web.stanford.edu/~ouster/cgi-bin/aposd.php) |
| `assertions` | **The Power of 10** (Holzmann, NASA/JPL) — assertion density; and **TigerStyle** (TigerBeetle) — assert the positive *and* negative space. | [P10 (PDF)](https://spinroot.com/gerard/pdf/P10.pdf) · [TIGER_STYLE.md](https://github.com/tigerbeetle/tigerbeetle/blob/main/docs/TIGER_STYLE.md) |
| `bounded` | **The Power of 10** (bound all loops) and **TigerStyle** ("bound everything"). | [P10 (PDF)](https://spinroot.com/gerard/pdf/P10.pdf) · [TIGER_STYLE.md](https://github.com/tigerbeetle/tigerbeetle/blob/main/docs/TIGER_STYLE.md) |
| `api-design` | **qodo-ai/pr-agent** reviewer prompt ("might break other code") and **github/awesome-copilot** generic code-review instructions (breaking changes). | [pr-agent](https://github.com/qodo-ai/pr-agent) · [awesome-copilot](https://github.com/github/awesome-copilot) |
| `type-safety` | Alexis King — **"Parse, don't validate"**; Yaron Minsky — **"Make illegal states unrepresentable"**. | [lexi-lambda](https://lexi-lambda.github.io/blog/2019/11/05/parse-don-t-validate/) · [Jane Street](https://blog.janestreet.com/effective-ml-revisited/) |
| `magic-values` | Martin Fowler — *Refactoring* (**Replace Magic Literal**); github/awesome-copilot generic review (magic numbers). | [refactoring.com](https://refactoring.com/catalog/replaceMagicLiteral.html) · [awesome-copilot](https://github.com/github/awesome-copilot) |
| `comment-why` | Google — **Engineering Practices / Code Review** ("comments should explain *why*, not *what*"); Ousterhout. | [google.github.io/eng-practices](https://google.github.io/eng-practices/review/reviewer/looking-for.html) |
| `observability` | github/awesome-copilot **security-and-owasp** (logging quality) and structured-logging practice. Excludes secrets/PII-in-logs (that stays in the built-in `security` lens). | [awesome-copilot](https://github.com/github/awesome-copilot) |
| `accessibility` | **eslint-plugin-jsx-a11y** (concrete a11y rule classes) and github/awesome-copilot accessibility instructions. | [eslint-plugin-jsx-a11y](https://github.com/jsx-eslint/eslint-plugin-jsx-a11y) · [awesome-copilot](https://github.com/github/awesome-copilot) |
| `idempotency` | **Original synthesis** from distributed-systems practice (at-least-once delivery; retry-safety). No single review-skill source; for the concept, see Stripe's idempotency-keys design. | [docs.stripe.com](https://docs.stripe.com/api/idempotent_requests) |
| `migrations` | **Original synthesis** from online-schema-change practice (expand/contract; lock-safe DDL). No single review-skill source; for the concept, see `strong_migrations`. | [ankane/strong_migrations](https://github.com/ankane/strong_migrations) |
| `i18n` | **Original synthesis** from general localization practice (externalized strings; locale-safe formatting; Unicode handling). | [cldr.unicode.org](https://cldr.unicode.org/) |
| `portability` | **Original synthesis** from cross-platform practice (POSIX, `pathlib`/temp-dir APIs, no hardcoded paths). | — |

## Ecosystems scanned

These collections were surveyed while curating the packs; ideas already covered by
the nine built-ins (OWASP security, correctness, deprecated/EOL deps, weak tests,
stale docs, N+1/quadratic performance, nesting/duplication, intent, YAGNI) were
deliberately **not** duplicated as new lenses:

- [github/awesome-copilot](https://github.com/github/awesome-copilot) — Copilot custom instructions.
- [baz-scm/awesome-reviewers](https://github.com/baz-scm/awesome-reviewers) — review prompts distilled from real maintainer feedback.
- [qodo-ai/pr-agent](https://github.com/qodo-ai/pr-agent) — PR-Agent reviewer prompts.
- [trailofbits/skills](https://github.com/trailofbits/skills) — security review skills (footgun/insecure-defaults framing).
- [obra/superpowers](https://github.com/obra/superpowers) — engineering skills (testing anti-patterns, code-review etiquette).
- [anthropics/skills](https://github.com/anthropics/skills) — official Agent Skills.

If you maintain one of these and want the attribution worded differently — or
removed — open an issue.
