diff --git a/frontend/src/app/pages/Dashboard/cards/BrowserReplayOverlay.tsx b/frontend/src/app/pages/Dashboard/cards/BrowserReplayOverlay.tsx
new file mode 100644
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+++ b/frontend/src/app/pages/Dashboard/cards/BrowserReplayOverlay.tsx
@@ -0,0 +1,128 @@
+/**
+ * PROTOTYPE (not wired yet): the "fast data mode" overlay for shadow-API replay.
+ *
+ * Shown over a BrowserCard for the brief moment the agent reads bulk data via the
+ * page's own JSON feed instead of scroll-scraping. It's an HONEST visualization,
+ * the rows are the real extracted records, revealed at once (one API call returns
+ * them all), not a fake cursor and not a faked progress counter.
+ *
+ * Built deliberately cheap, OpenSwarm is memory/compute-sensitive and the webview
+ * compositor is fragile:
+ *   - NO backdrop-blur. The overlay is OPAQUE, so it fully covers the <webview>
+ *     and the compositor can stop painting it while covered. Blur over a webview
+ *     is paint-heavy and risky here.
+ *   - Animations are opacity/transform ONLY (compositor-only; no layout/paint).
+ *   - Rows reveal via a SINGLE reused @keyframes + per-row animation-delay, pure
+ *     CSS, zero per-row JS, state, timers, or WS messages.
+ *   - No shimmer loops. The only infinite animation is one tiny opacity-pulse dot.
+ *   - Renders at most MAX_VISIBLE rows (the full set goes to the agent, not here).
+ *   - unmountOnExit => literally zero cost when not replaying.
+ */
+import React from 'react';
+import Box from '@mui/material/Box';
+import Fade from '@mui/material/Fade';
+import { useClaudeTokens } from '@/shared/styles/ThemeContext';
+
+export interface ReplayRow {
+  title: string;
+  subtitle?: string;
+}
+
+export interface BrowserReplayOverlayProps {
+  active: boolean;
+  site: string;                          // plain name, e.g. "LinkedIn"
+  rows: ReplayRow[];                     // real extracted records (one payload)
+  total: number;
+  status: 'reading' | 'done' | 'empty';
+  elapsedMs?: number;
+}
+
+const MAX_VISIBLE = 6;                    // cap the DOM; the count conveys the rest
+
+function BrowserReplayOverlay({
+  active, site, rows, total, status, elapsedMs,
+}: BrowserReplayOverlayProps) {
+  const c = useClaudeTokens();
+  const shown = rows.length > MAX_VISIBLE ? rows.slice(0, MAX_VISIBLE) : rows;
+
+  const header =
+    status === 'done'
+      ? `✓ ${total} result${total === 1 ? '' : 's'}${elapsedMs != null ? ` · ${(elapsedMs / 1000).toFixed(1)}s` : ''}`
+      : status === 'empty'
+        ? `${site}'s feed came back empty, browsing instead`
+        : `Reading ${site}'s data feed`;
+
+  return (
+    <Fade in={active} timeout={{ enter: 200, exit: 220 }} unmountOnExit>
+      <Box
+        aria-label="fast data read"
+        sx={{
+          position: 'absolute', inset: 0, zIndex: 5,
+          bgcolor: c.bg.surface,             // opaque on purpose (see file header)
+          display: 'flex', flexDirection: 'column', gap: 0.75,
+          p: 1.25, overflow: 'hidden',
+          fontFamily: c.font.sans,
+          '@keyframes os-replay-row': {
+            from: { opacity: 0, transform: 'translateY(6px)' },
+            to: { opacity: 1, transform: 'translateY(0)' },
+          },
+          '@keyframes os-replay-dot': {
+            '0%, 100%': { opacity: 0.3 },
+            '50%': { opacity: 1 },
+          },
+        }}
+      >
+        <Box sx={{
+          display: 'flex', alignItems: 'center', gap: 0.5,
+          fontSize: 12, fontWeight: 600,
+          color: status === 'done' ? c.accent.primary : c.text.secondary,
+          minWidth: 0,
+        }}>
+          {status === 'reading' && (
+            <Box component="span" sx={{
+              flex: '0 0 auto', width: 6, height: 6, borderRadius: '50%',
+              bgcolor: c.accent.primary,
+              animation: 'os-replay-dot 1.2s ease-in-out infinite',
+            }} />
+          )}
+          <Box component="span" sx={{ overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap' }}>
+            {header}
+          </Box>
+        </Box>
+
+        {status !== 'empty' && (
+          <Box sx={{ display: 'flex', flexDirection: 'column', gap: 0.4, minHeight: 0 }}>
+            {shown.map((r, i) => (
+              <Box
+                key={`${i}-${r.title}`}
+                sx={{
+                  animation: 'os-replay-row 180ms ease-out both',
+                  animationDelay: `${i * 45}ms`,
+                  display: 'flex', alignItems: 'baseline', gap: 0.75,
+                  fontSize: 12.5, color: c.text.primary,
+                  whiteSpace: 'nowrap', overflow: 'hidden', textOverflow: 'ellipsis',
+                }}
+              >
+                <Box component="span" aria-hidden sx={{ flex: '0 0 auto', color: c.text.tertiary }}>{'▸'}</Box>
+                <Box component="span" sx={{ fontWeight: 500, flex: '0 0 auto' }}>{r.title}</Box>
+                {r.subtitle && (
+                  <Box component="span" sx={{ color: c.text.tertiary, overflow: 'hidden', textOverflow: 'ellipsis' }}>
+                    {r.subtitle}
+                  </Box>
+                )}
+              </Box>
+            ))}
+          </Box>
+        )}
+
+        <Box sx={{ mt: 'auto', fontSize: 11, color: c.text.tertiary }}>
+          via the page&apos;s own data feed
+        </Box>
+      </Box>
+    </Fade>
+  );
+}
+
+// memo: re-render only when the inputs actually change (cheap, but free insurance
+// against parent BrowserCard re-renders during an agent run).
+export default React.memo(BrowserReplayOverlay);