vercel / streamdown

The skill walks through installing the npm package, adding the required Tailwind @source line so its utility classes survive Tailwind's purge (with a separate path for monorepos where dependencies are hoisted to a root node_modules), setting the CSS custom properties the components read for color, radius, and spacing, and wiring up the four optional plugins -- code, mermaid, math, and cjk -- for syntax highlighting, diagrams, LaTeX, and CJK text. It also covers styling, link and HTML security settings, and switching between animated and static rendering.

This is for a team already using the Vercel AI SDK's streaming chat hooks that needs Markdown to render correctly while a response is still arriving -- the incomplete-block problem the README describes as the reason Streamdown exists, and the one the skill is built around. It isn't a general react-markdown replacement skill for content that's already complete when it renders.

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The setup has a real trap for anyone not already on shadcn/ui. Streamdown's components are styled through CSS custom properties -- background, foreground, border, and the rest -- that shadcn/ui projects already define; the README says that without them, components can render with missing backgrounds, borders, or spacing. A project that isn't on shadcn/ui has to add that block of variables by hand before the components look right, not after something visibly breaks.

We have no confirmed license on record for this repository. Every other field we checked came back clean -- one skill, one dependency label (local_tool), Vercel's own account behind it -- but the license value is empty in our data, so check the repository directly before relying on its terms.