Each folder is one CraftCode pattern as a real before / after pair you can open
side by side — not a snippet buried in prose. The before reads like fresh
AI output; the after reads like a senior wrote it. Same behavior, different texture.
The patterns are spread across six languages on purpose: they are language-agnostic. The idea is the same whether you write Python, Go, Rust, JavaScript, or CSS.
| # | Pattern | Language | What the diff shows |
|---|---|---|---|
| 01 | Intent comments | Python | Delete the what-comments; keep one why-comment on the non-obvious in-place mutation. |
| 02 | Fail-open / fail-closed | Go | Peripheral (logger, plugin) degrades and continues; auth denies when it can't verify. |
| 03 | Idempotency awareness | Python | Charge + email move out of the retry loop; retry only transient errors. |
| 04 | Native over library | JavaScript | Drop AOS / Moment / Lodash for IntersectionObserver, Date, and Set. |
| 05 | Constraints baked in | HTML + CSS | Self-hosted font + click-to-load map — privacy designed in, not bolted on. |
| 06 | Defensive boundary, clean core | Rust | Parsing fenced at the edge; the core is one honest sum(). |
Pattern 0 (mirror the neighbors before you write) has no standalone example — by definition it only shows up inside a project, matching the files already there.
Read the reasoning behind each in ../SKILL.md, and see the evidence
the skill actually changes model output in ../PROOF.md.