Citations
Inline citation markers paired with a collapsible, progressively rendered reference collection for grounded agent responses.
Preview
TSXcomponents/previews/agents/citations.preview.tsx
"use client";
import { RotateCcw } from "lucide-react";
import { useReducedMotion } from "motion/react";
import { useEffect, useState } from "react";
import {
Citation,
Citations,
type CitationItem,
} from "@/components/agents/citations";
const CITATION_ITEMS: CitationItem[] = [
{
id: "motion",
title: "Motion documentation",
domain: "motion.dev",
url: "https://motion.dev/docs/react",
},
{
id: "wai",
title: "WAI accessibility patterns",
domain: "w3.org",
url: "https://www.w3.org/WAI/ARIA/apg/",
},
{
id: "react",
title: "React documentation",
domain: "react.dev",
url: "https://react.dev/learn",
},
];
function CitationsDemo() {
const reduce = useReducedMotion() ?? false;
const [visible, setVisible] = useState(reduce ? CITATION_ITEMS.length : 0);
useEffect(() => {
if (reduce) return;
const timers = CITATION_ITEMS.map((_, index) =>
window.setTimeout(() => setVisible(index + 1), 500 + index * 700),
);
return () => timers.forEach(window.clearTimeout);
}, [reduce]);
return (
<div className="space-y-4">
<p className="text-sm leading-6 text-foreground/90">
Use layout-aware motion for newly appended results{" "}
<Citation citationId="motion" index={1} idPrefix="preview-source" /> and preserve accessible
disclosure behavior <Citation citationId="wai" index={2} idPrefix="preview-source" /> as the list
grows.
</p>
<Citations
idPrefix="preview-source"
citations={CITATION_ITEMS.slice(0, visible)}
defaultOpen
/>
</div>
);
}
export function CitationsPreview() {
const [run, setRun] = useState(0);
return (
<div className="relative h-[410px] w-full max-w-lg">
<CitationsDemo key={run} />
<button
type="button"
onClick={() => setRun((value) => value + 1)}
className="absolute bottom-0 left-0 inline-flex items-center gap-1.5 rounded-md px-2 py-1 text-xs font-medium text-muted-foreground outline-none transition-colors hover:bg-muted hover:text-foreground focus-visible:ring-2 focus-visible:ring-ring"
>
<RotateCcw className="size-3" />
Replay
</button>
</div>
);
}
TSXcomponents/agents/citations.tsx
"use client";
// beui.dev/components/agents/citations
import { BookOpenText, ChevronDown, ExternalLink, Globe2 } from "lucide-react";
import { AnimatePresence, motion, useReducedMotion } from "motion/react";
import {
type ReactNode,
useCallback,
useId,
useState,
} from "react";
import { AgentDisclosure } from "@/components/agents/agent-disclosure";
import { EASE_OUT, SPRING_LAYOUT, SPRING_SWAP } from "@/lib/ease";
import { getFaviconUrl } from "@/lib/favicon";
import { cn } from "@/lib/utils";
export interface CitationItem {
id: string;
title: ReactNode;
domain?: ReactNode;
url?: string;
}
export interface CitationsProps {
citations: CitationItem[];
title?: ReactNode;
open?: boolean;
defaultOpen?: boolean;
onOpenChange?: (open: boolean) => void;
idPrefix?: string;
className?: string;
}
export interface CitationProps {
citationId: string;
index: number;
/** Must match the related Citations idPrefix. */
idPrefix: string;
className?: string;
}
export interface CitationListProps {
citations: CitationItem[];
idPrefix?: string;
className?: string;
}
export interface CitationStackProps {
citations: CitationItem[];
limit?: number;
className?: string;
}
function citationTargetId(prefix: string, citationId: string) {
return `${prefix}-${citationId.replace(/[^a-zA-Z0-9_-]/g, "-")}`;
}
export function Citation({
citationId,
index,
idPrefix,
className,
}: CitationProps) {
return (
<a
href={`#${citationTargetId(idPrefix, citationId)}`}
aria-label={`View citation ${index}`}
className={cn(
"mx-0.5 inline-flex min-w-4 -translate-y-0.5 items-center justify-center rounded-md bg-muted/60 px-1 py-0.5 text-[10px] font-semibold leading-none text-muted-foreground no-underline outline-none transition-colors hover:text-foreground focus-visible:ring-2 focus-visible:ring-ring",
className,
)}
>
{index}
</a>
);
}
export function CitationFavicon({
url,
className,
}: {
url?: string;
className?: string;
}) {
const favicon = url ? getFaviconUrl(url) : null;
const [failedUrl, setFailedUrl] = useState<string | null>(null);
return (
<span
aria-hidden="true"
className={cn(
"grid size-5 shrink-0 place-items-center text-muted-foreground",
className,
)}
>
{favicon && failedUrl !== favicon ? (
// biome-ignore lint/performance/noImgElement: Dynamic cross-site favicons keep this framework-agnostic registry component portable.
<img
src={favicon}
alt=""
width={16}
height={16}
referrerPolicy="no-referrer"
onError={() => setFailedUrl(favicon)}
className="size-4 rounded-sm object-contain"
/>
) : (
<Globe2 className="size-3.5" />
)}
</span>
);
}
export function CitationStack({
citations,
limit = 3,
className,
}: CitationStackProps) {
return (
<span
aria-hidden="true"
className={cn("flex -space-x-1.5", className)}
>
{citations.slice(0, limit).map((citation) => (
<CitationFavicon
key={citation.id}
url={citation.url}
className="size-6 rounded-full bg-background ring-2 ring-background"
/>
))}
</span>
);
}
function CitationRow({
citation,
index,
idPrefix,
}: {
citation: CitationItem;
index: number;
idPrefix: string;
}) {
const content = (
<>
<CitationFavicon url={citation.url} />
<span className="flex min-w-0 flex-1 flex-wrap items-baseline gap-x-2 gap-y-0.5">
<span className="truncate text-sm font-medium text-foreground/80 transition-colors group-hover/citation:text-foreground">
{citation.title}
</span>
{citation.domain ? (
<span className="min-w-0 truncate text-xs text-muted-foreground/60">
{citation.domain}
</span>
) : null}
</span>
<span className="flex shrink-0 items-center gap-1.5">
<span className="grid size-5 place-items-center rounded-md bg-foreground/[0.05] text-[10px] font-semibold tabular-nums text-muted-foreground">
{index}
</span>
{citation.url ? (
<ExternalLink className="size-3.5 text-muted-foreground/40 transition-colors group-hover/citation:text-muted-foreground" />
) : null}
</span>
</>
);
const className =
"group/citation flex items-center gap-2 rounded-md px-1.5 py-1 outline-none focus-visible:ring-2 focus-visible:ring-ring";
const id = citationTargetId(idPrefix, citation.id);
return citation.url ? (
<a
id={id}
href={citation.url}
target="_blank"
rel="noreferrer noopener"
className={className}
>
{content}
</a>
) : (
<div id={id} className={className}>
{content}
</div>
);
}
export function CitationList({
citations,
idPrefix,
className,
}: CitationListProps) {
const reduce = useReducedMotion() ?? false;
const baseId = useId();
const resolvedPrefix =
idPrefix ?? `citation-list-${baseId.replace(/:/g, "")}`;
return (
<div className={cn("grid gap-0.5", className)}>
<AnimatePresence mode="popLayout">
{citations.map((citation, index) => (
<motion.div
layout="position"
key={citation.id}
initial={reduce ? { opacity: 1 } : { opacity: 0, y: 6 }}
animate={{ opacity: 1, y: 0 }}
exit={reduce ? { opacity: 0 } : { opacity: 0, y: -3 }}
transition={
reduce
? { duration: 0 }
: {
opacity: { duration: 0.18, ease: EASE_OUT },
y: SPRING_LAYOUT,
layout: SPRING_LAYOUT,
}
}
>
<CitationRow
citation={citation}
index={index + 1}
idPrefix={resolvedPrefix}
/>
</motion.div>
))}
</AnimatePresence>
</div>
);
}
export function Citations({
citations,
title = "Sources",
open,
defaultOpen = false,
onOpenChange,
idPrefix,
className,
}: CitationsProps) {
const reduce = useReducedMotion() ?? false;
const baseId = useId();
const contentId = `${baseId}-content`;
const resolvedPrefix =
idPrefix ?? `citation-${baseId.replace(/:/g, "")}`;
const [internalOpen, setInternalOpen] = useState(defaultOpen);
const currentOpen = open ?? internalOpen;
const setOpen = useCallback(
(next: boolean) => {
if (open === undefined) setInternalOpen(next);
onOpenChange?.(next);
},
[onOpenChange, open],
);
return (
<div className={cn("w-full text-sm", className)}>
<button
type="button"
aria-expanded={currentOpen}
aria-controls={contentId}
onClick={() => setOpen(!currentOpen)}
className="group -ml-1 flex min-h-8 items-center gap-2 rounded-lg px-1 text-left text-muted-foreground outline-none transition-colors hover:text-foreground focus-visible:ring-2 focus-visible:ring-ring"
>
<BookOpenText className="size-4" />
<span className="font-medium">{title}</span>
<span className="rounded-full bg-muted px-1.5 py-0.5 text-[10px] font-semibold tabular-nums">
{citations.length}
</span>
<motion.span
aria-hidden="true"
animate={{ rotate: currentOpen ? 180 : 0 }}
transition={reduce ? { duration: 0 } : SPRING_SWAP}
className="text-muted-foreground/60"
>
<ChevronDown className="size-3.5" />
</motion.span>
</button>
<AgentDisclosure
id={contentId}
open={currentOpen}
>
<CitationList
citations={citations}
idPrefix={resolvedPrefix}
className="mt-1"
/>
</AgentDisclosure>
</div>
);
}
Install
Add it with the shadcn CLI, or copy the source manually.
$ bunx --bun shadcn add @beui/citations
Needs the theme tokens once. Already ran
shadcn init? You are set. Theme setupInstall dependencies
npm i clsx lucide-react motion tailwind-mergeAdd util files
TSXlib/ease.ts
// Shared motion tokens. Easing curves mirror the CSS custom properties in
// globals.css; springs are the canonical physics used across components.
// Strong custom variants — defaults like `ease-in`/`ease-out` feel weak.
export const EASE_OUT = [0.16, 1, 0.3, 1] as const;
export const EASE_IN_OUT = [0.77, 0, 0.175, 1] as const;
export const EASE_DRAWER = [0.32, 0.72, 0, 1] as const;
/** CSS string form of EASE_OUT for inline style transitions. */
export const EASE_OUT_CSS = "cubic-bezier(0.16, 1, 0.3, 1)";
/** Press feedback on buttons and other tappable surfaces. */
export const SPRING_PRESS = {
type: "spring",
stiffness: 500,
damping: 30,
mass: 0.6,
} as const;
/** Content swaps — label/icon slots trading places inside a control. */
export const SPRING_SWAP = {
type: "spring",
stiffness: 460,
damping: 30,
mass: 0.55,
} as const;
/** Overlay panel entrances — modals and sheets summoned by pointer. */
export const SPRING_PANEL = {
type: "spring",
stiffness: 420,
damping: 40,
mass: 0.5,
} as const;
/** Shared-layout glides — pills, indicators and panels morphing between positions. */
export const SPRING_LAYOUT = {
type: "spring",
stiffness: 360,
damping: 32,
mass: 0.6,
} as const;
/** Cursor-follow physics for decorative mouse tracking (magnetic, tilt, dock). */
export const SPRING_MOUSE = {
stiffness: 200,
damping: 15,
mass: 0.3,
} as const;
/** Dragged handles and fills (sliders) — critically damped `useSpring` config,
* so the value follows the pointer butterily and never rebounds off an end. */
export const SPRING_GLIDE = {
stiffness: 700,
damping: 50,
mass: 0.5,
} as const;
TSXlib/favicon.ts
/** Resolve a website URL to its conventional root favicon location. */
export function getFaviconUrl(value: string) {
try {
return new URL("/favicon.ico", value).toString();
} catch {
return null;
}
}
TSXlib/utils.ts
import { clsx, type ClassValue } from "clsx"
import { twMerge } from "tailwind-merge"
export function cn(...inputs: ClassValue[]) {
return twMerge(clsx(inputs))
}
Copy the source code
TSXcomponents/agents/citations.tsx
"use client";
// beui.dev/components/agents/citations
import { BookOpenText, ChevronDown, ExternalLink, Globe2 } from "lucide-react";
import { AnimatePresence, motion, useReducedMotion } from "motion/react";
import {
type ReactNode,
useCallback,
useId,
useState,
} from "react";
import { AgentDisclosure } from "@/components/agents/agent-disclosure";
import { EASE_OUT, SPRING_LAYOUT, SPRING_SWAP } from "@/lib/ease";
import { getFaviconUrl } from "@/lib/favicon";
import { cn } from "@/lib/utils";
export interface CitationItem {
id: string;
title: ReactNode;
domain?: ReactNode;
url?: string;
}
export interface CitationsProps {
citations: CitationItem[];
title?: ReactNode;
open?: boolean;
defaultOpen?: boolean;
onOpenChange?: (open: boolean) => void;
idPrefix?: string;
className?: string;
}
export interface CitationProps {
citationId: string;
index: number;
/** Must match the related Citations idPrefix. */
idPrefix: string;
className?: string;
}
export interface CitationListProps {
citations: CitationItem[];
idPrefix?: string;
className?: string;
}
export interface CitationStackProps {
citations: CitationItem[];
limit?: number;
className?: string;
}
function citationTargetId(prefix: string, citationId: string) {
return `${prefix}-${citationId.replace(/[^a-zA-Z0-9_-]/g, "-")}`;
}
export function Citation({
citationId,
index,
idPrefix,
className,
}: CitationProps) {
return (
<a
href={`#${citationTargetId(idPrefix, citationId)}`}
aria-label={`View citation ${index}`}
className={cn(
"mx-0.5 inline-flex min-w-4 -translate-y-0.5 items-center justify-center rounded-md bg-muted/60 px-1 py-0.5 text-[10px] font-semibold leading-none text-muted-foreground no-underline outline-none transition-colors hover:text-foreground focus-visible:ring-2 focus-visible:ring-ring",
className,
)}
>
{index}
</a>
);
}
export function CitationFavicon({
url,
className,
}: {
url?: string;
className?: string;
}) {
const favicon = url ? getFaviconUrl(url) : null;
const [failedUrl, setFailedUrl] = useState<string | null>(null);
return (
<span
aria-hidden="true"
className={cn(
"grid size-5 shrink-0 place-items-center text-muted-foreground",
className,
)}
>
{favicon && failedUrl !== favicon ? (
// biome-ignore lint/performance/noImgElement: Dynamic cross-site favicons keep this framework-agnostic registry component portable.
<img
src={favicon}
alt=""
width={16}
height={16}
referrerPolicy="no-referrer"
onError={() => setFailedUrl(favicon)}
className="size-4 rounded-sm object-contain"
/>
) : (
<Globe2 className="size-3.5" />
)}
</span>
);
}
export function CitationStack({
citations,
limit = 3,
className,
}: CitationStackProps) {
return (
<span
aria-hidden="true"
className={cn("flex -space-x-1.5", className)}
>
{citations.slice(0, limit).map((citation) => (
<CitationFavicon
key={citation.id}
url={citation.url}
className="size-6 rounded-full bg-background ring-2 ring-background"
/>
))}
</span>
);
}
function CitationRow({
citation,
index,
idPrefix,
}: {
citation: CitationItem;
index: number;
idPrefix: string;
}) {
const content = (
<>
<CitationFavicon url={citation.url} />
<span className="flex min-w-0 flex-1 flex-wrap items-baseline gap-x-2 gap-y-0.5">
<span className="truncate text-sm font-medium text-foreground/80 transition-colors group-hover/citation:text-foreground">
{citation.title}
</span>
{citation.domain ? (
<span className="min-w-0 truncate text-xs text-muted-foreground/60">
{citation.domain}
</span>
) : null}
</span>
<span className="flex shrink-0 items-center gap-1.5">
<span className="grid size-5 place-items-center rounded-md bg-foreground/[0.05] text-[10px] font-semibold tabular-nums text-muted-foreground">
{index}
</span>
{citation.url ? (
<ExternalLink className="size-3.5 text-muted-foreground/40 transition-colors group-hover/citation:text-muted-foreground" />
) : null}
</span>
</>
);
const className =
"group/citation flex items-center gap-2 rounded-md px-1.5 py-1 outline-none focus-visible:ring-2 focus-visible:ring-ring";
const id = citationTargetId(idPrefix, citation.id);
return citation.url ? (
<a
id={id}
href={citation.url}
target="_blank"
rel="noreferrer noopener"
className={className}
>
{content}
</a>
) : (
<div id={id} className={className}>
{content}
</div>
);
}
export function CitationList({
citations,
idPrefix,
className,
}: CitationListProps) {
const reduce = useReducedMotion() ?? false;
const baseId = useId();
const resolvedPrefix =
idPrefix ?? `citation-list-${baseId.replace(/:/g, "")}`;
return (
<div className={cn("grid gap-0.5", className)}>
<AnimatePresence mode="popLayout">
{citations.map((citation, index) => (
<motion.div
layout="position"
key={citation.id}
initial={reduce ? { opacity: 1 } : { opacity: 0, y: 6 }}
animate={{ opacity: 1, y: 0 }}
exit={reduce ? { opacity: 0 } : { opacity: 0, y: -3 }}
transition={
reduce
? { duration: 0 }
: {
opacity: { duration: 0.18, ease: EASE_OUT },
y: SPRING_LAYOUT,
layout: SPRING_LAYOUT,
}
}
>
<CitationRow
citation={citation}
index={index + 1}
idPrefix={resolvedPrefix}
/>
</motion.div>
))}
</AnimatePresence>
</div>
);
}
export function Citations({
citations,
title = "Sources",
open,
defaultOpen = false,
onOpenChange,
idPrefix,
className,
}: CitationsProps) {
const reduce = useReducedMotion() ?? false;
const baseId = useId();
const contentId = `${baseId}-content`;
const resolvedPrefix =
idPrefix ?? `citation-${baseId.replace(/:/g, "")}`;
const [internalOpen, setInternalOpen] = useState(defaultOpen);
const currentOpen = open ?? internalOpen;
const setOpen = useCallback(
(next: boolean) => {
if (open === undefined) setInternalOpen(next);
onOpenChange?.(next);
},
[onOpenChange, open],
);
return (
<div className={cn("w-full text-sm", className)}>
<button
type="button"
aria-expanded={currentOpen}
aria-controls={contentId}
onClick={() => setOpen(!currentOpen)}
className="group -ml-1 flex min-h-8 items-center gap-2 rounded-lg px-1 text-left text-muted-foreground outline-none transition-colors hover:text-foreground focus-visible:ring-2 focus-visible:ring-ring"
>
<BookOpenText className="size-4" />
<span className="font-medium">{title}</span>
<span className="rounded-full bg-muted px-1.5 py-0.5 text-[10px] font-semibold tabular-nums">
{citations.length}
</span>
<motion.span
aria-hidden="true"
animate={{ rotate: currentOpen ? 180 : 0 }}
transition={reduce ? { duration: 0 } : SPRING_SWAP}
className="text-muted-foreground/60"
>
<ChevronDown className="size-3.5" />
</motion.span>
</button>
<AgentDisclosure
id={contentId}
open={currentOpen}
>
<CitationList
citations={citations}
idPrefix={resolvedPrefix}
className="mt-1"
/>
</AgentDisclosure>
</div>
);
}
TSXcomponents/agents/agent-disclosure.tsx
"use client";
import { motion, type HTMLMotionProps, useReducedMotion } from "motion/react";
import type { CSSProperties } from "react";
import { EASE_OUT } from "@/lib/ease";
import { cn } from "@/lib/utils";
export interface AgentDisclosureProps
extends Omit<HTMLMotionProps<"div">, "animate" | "initial"> {
open: boolean;
openHeight?: CSSProperties["height"];
}
/** Shared transform-only reveal for collapsible agent content. */
export function AgentDisclosure({
open,
openHeight = "auto",
className,
style,
transition,
...props
}: AgentDisclosureProps) {
const reduce = useReducedMotion() ?? false;
return (
<motion.div
{...props}
aria-hidden={!open}
inert={!open}
initial={false}
animate={
reduce
? { opacity: open ? 1 : 0 }
: {
opacity: open ? 1 : 0,
clipPath: open ? "inset(0 0 0% 0)" : "inset(0 0 100% 0)",
y: open ? 0 : -4,
}
}
transition={
transition ?? {
duration: reduce ? 0 : open ? 0.22 : 0.14,
ease: EASE_OUT,
}
}
className={cn("overflow-hidden", className)}
style={{
...style,
height: open ? openHeight : 0,
pointerEvents: open ? undefined : "none",
transformOrigin: "top",
}}
/>
);
}
API Reference
Citation
citationIdstring—indexnumber—idPrefixstringMust match the related Citations idPrefix.
—className?string—CitationFavicon
url?string—className?string—CitationStack
citationsCitationItem[]—limit?number3className?string—CitationList
citationsCitationItem[]—idPrefix?string—className?string—Citations
citationsCitationItem[]—title?ReactNodeSourcesopen?boolean—defaultOpen?booleanfalseonOpenChange?((open: boolean) => void)—idPrefix?string—className?string—Composition
Pair inline citation markers with a source disclosure owned by the same response.
StreamingResponse
├── Citation
└── Citations
├── CitationStack
└── CitationListNote: Streaming Response reveals the source summary when the answer completes. Message keeps cited answers within a semantic conversation row.
How it works
Citations connect a claim to supporting material without interrupting the answer. Inline markers should stay lightweight while the source collection provides enough information to inspect the evidence.
Updated