VLLNT UI vs assistant-ui

assistant-ui gives you an opinionated chat thread fast. VLLNT UI is a broader, agent-first design system: the same chat surfaces, plus the tool calls, agent activity, citations, artifacts, and product UI an AI-first app needs — all installed via the shadcn CLI so you own the source.

AttributeVLLNT UIassistant-ui
ScopeFull design system — chat plus agents, artifacts, and 200+ UI componentsFocused on the chat/assistant thread experience
Install modelshadcn CLI — source copied into your repo, yours to editnpm dependency with a runtime
Beyond chatTool calls, agent activity, citations, model comparison, artifacts, dashboardsPrimarily conversation-centric
Agent-readable registryYes — llms.txt, llms-full.txt, per-component JSON, MCPNo
ThemingCSS variables + design tokens shared across the whole productThemeable chat primitives
When to pick itYou're building a whole AI-first product, not just a chat boxYou want an opinionated chat thread fast