diff --git a/scripts/verify-aiui-deploy.sh b/scripts/verify-aiui-deploy.sh
new file mode 100755
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+++ b/scripts/verify-aiui-deploy.sh
@@ -0,0 +1,85 @@
+#!/usr/bin/env bash
+# verify-aiui-deploy.sh — post-deploy check that a marker string is actually
+# reachable by a browser loading AIUI, not merely present somewhere on disk.
+#
+# The node's /opt/archipelago/web-ui/aiui/assets/ directory is a
+# never-pruned graveyard: nginx never deletes an old build's chunk files
+# when a new build lands (only the tar+rsync step below AIUI_DIST replaces
+# what's there, and even that has left orphaned files in past incidents —
+# see feedback_node_side_frontend_verify_stale_chunks). A disk grep over
+# assets/ can therefore report "deployed" before the deploy actually
+# happened, because a DEAD chunk from an old build still contains the old
+# string. The only honest check fetches what a browser would actually load:
+# resolve the LIVE chunk set via the service worker's precache manifest
+# (sw.js), fetch each live chunk over HTTP, and grep the fetched bytes.
+#
+# This script never opens a remote shell session onto the node and never
+# greps the node's filesystem directly — every check here is an HTTP
+# fetch, exactly what a browser session would do.
+#
+# Usage:
+#   ./verify-aiui-deploy.sh <node-host> "<marker string>"
+#
+# Exit 0  = the marker was found in at least one live chunk fetched over HTTP.
+# Exit 1  = the marker was not found in any live chunk (negative control
+#           should also produce this — a check that always passes is not a
+#           check).
+
+set -uo pipefail
+
+HOST="${1:?usage: verify-aiui-deploy.sh <node-host> \"<marker string>\"}"
+MARKER="${2:?usage: verify-aiui-deploy.sh <node-host> \"<marker string>\"}"
+
+# Accept a bare host or a host:port; default to plain HTTP on :80, matching
+# how neode-ui/AIUI are actually served on a node (nginx terminates TLS
+# elsewhere; the lifecycle gate and other production-quality scripts in
+# this directory talk to nodes over plain HTTP the same way).
+BASE="http://${HOST}"
+SW_URL="${BASE}/aiui/sw.js"
+
+timestamp() { echo "[$(date +%H:%M:%S)]"; }
+
+echo "$(timestamp) Fetching service worker manifest: $SW_URL"
+SW_BODY="$(curl -sf -m 15 "$SW_URL" 2>/dev/null || true)"
+if [ -z "$SW_BODY" ]; then
+    echo "FATAL: could not fetch $SW_URL — is AIUI deployed and nginx up on $HOST?" >&2
+    exit 1
+fi
+
+# vite-plugin-pwa's generateSW mode emits sw.js with a
+# workbox.precacheAndRoute([{url:"...",revision:"..."|null}, ...]) call —
+# a JS array literal (unquoted keys), not JSON. Extract every url:"..."
+# value without a full JS parser.
+mapfile -t LIVE_PATHS < <(
+    grep -oE 'url:"[^"]*"' <<<"$SW_BODY" | sed -E 's/^url:"//; s/"$//'
+)
+
+if [ "${#LIVE_PATHS[@]}" -eq 0 ]; then
+    echo "FATAL: $SW_URL fetched but no precache entries found — cannot resolve live chunks." >&2
+    exit 1
+fi
+
+echo "$(timestamp) Resolved ${#LIVE_PATHS[@]} live chunk(s) from the precache manifest."
+
+FOUND=0
+CHECKED=0
+for path in "${LIVE_PATHS[@]}"; do
+    [ -z "$path" ] && continue
+    CHECKED=$((CHECKED + 1))
+    url="${BASE}/aiui/${path}"
+    if curl -sf -m 15 "$url" 2>/dev/null | grep -q -- "$MARKER"; then
+        echo "$(timestamp)   MATCH: $path"
+        FOUND=1
+        break
+    fi
+done
+
+echo "$(timestamp) Checked $CHECKED live chunk(s) fetched over HTTP for marker: $MARKER"
+
+if [ "$FOUND" -eq 1 ]; then
+    echo "$(timestamp) PASS — marker found in a live, browser-fetchable chunk."
+    exit 0
+else
+    echo "$(timestamp) FAIL — marker not found in any live chunk (fetched via sw.js manifest, not a disk grep)." >&2
+    exit 1
+fi