most of the people reading this are not people
a design system is a set of rules about what to reach for and what to leave alone. that is exactly the kind of thing an agent gets wrong by default: it will happily put three attention-heavy components in one region because each of them, on its own, looked good. so the rules have to be machine readable, not just written down on a page.
the skill
one file, at https://usva.build/skill.md. it carries the seven rules that survive a truncated read, the layer and intensity table, the workflow, the role tokens, what each import actually costs, and all 79 components with their import paths. it regenerates from the same catalog the library builds from, so it cannot fall behind.
mkdir -p .claude/skills/usva
curl -o .claude/skills/usva/SKILL.md https://usva.build/skill.mdno agent skills in your harness? the file is plain markdown with frontmatter. save it as AGENTS.md, or paste it as a system prompt.
the part worth installing it for
most of the skill is what you would expect. the section that earns it is the gotchas table: eight ways this library fails quietly. a barrel import whose export graph is the entire library, shader runtimes included. a canvas chrome blanks because an ancestor animates. a reveal that never fires because it is parked outside its own mask. every one of them passes a build, passes the types, and often looks fine in a screenshot. none is guessable from a list of components, which is the whole reason the file exists.
llms.txt
the raw index, at https://usva.build/llms.txt. every one of the 79 components is a markdown link, carrying its layer, its intensity, a one line summary, the composition prohibitions and the registry command. the pages and the design-language chapters are linked the same way. a parser lifts the links, a model reads the prose. reach for this one when you want the catalogue rather than the rules.
the shortest useful prompt
if you cannot install anything at all.
read https://usva.build/llms.txt before you build any UI.
use usva components. obey the intensity rules:
core recedes, patterns structure, sula asserts,
one sula element per region, at most.