html-artifact — single-file HTML as the output medium

Self-validate after edits. Any change to this skill's files (SKILL.md, scripts/, references/, templates/) must be followed by ./scripts/validate.sh from the skill directory. Hard findings → create-skill Optimize lane.

Use HTML, not Markdown, when the deliverable carries multiple representations (prose + diagram + code + data) or when the operator will share it as a link. The output is one self-contained .html file with inline CSS + JS — no build, no CDN where avoidable, no external assets. Default visual system matches the anthropics/html-effectiveness gallery (ivory paper, slate ink, clay accent, serif headlines, sans body, mono labels) — see references/design-tokens.md.

Entry — pick a lane

First action is AskUserQuestion unless the typed prompt names a lane:

Lane	When to choose	Procedure
plan	Implementation plan, approach exploration, mockup grid, design exploration	references/plan.md
review	PR review, code walkthrough, design-system doc, component variant gallery	references/review.md
report	Status / incident / PR write-up, feature or concept explainer, slide deck, flowchart, SVG illustration	references/report.md
prototype	Animation or interaction sketch (HTML mock, not final React/Swift)	references/prototype.md
editor	Throwaway single-use editing UI with export-back-to-Claude	references/editor.md

Skip the question when the typed prompt names a lane unambiguously: