diff --git a/package.json b/package.json
index c71658639..d30819ce8 100644
--- a/package.json
+++ b/package.json
@@ -56,7 +56,7 @@
     "protocol:gen": "tsx scripts/protocol-gen.ts",
     "protocol:gen:swift": "tsx scripts/protocol-gen-swift.ts",
     "protocol:check": "pnpm protocol:gen && pnpm protocol:gen:swift && git diff --exit-code -- dist/protocol.schema.json apps/macos/Sources/ClawdisProtocol/GatewayModels.swift",
-    "canvas:a2ui:bundle": "pnpm -s exec tsc -p vendor/a2ui/renderers/lit/tsconfig.json && rolldown -c apps/shared/ClawdisKit/Tools/CanvasA2UI/rolldown.config.mjs"
+    "canvas:a2ui:bundle": "bash scripts/bundle-a2ui.sh"
   },
   "keywords": [],
   "author": "",
diff --git a/scripts/bundle-a2ui.sh b/scripts/bundle-a2ui.sh
new file mode 100755
index 000000000..f6f79d85d
--- /dev/null
+++ b/scripts/bundle-a2ui.sh
@@ -0,0 +1,45 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+HASH_FILE="$ROOT_DIR/src/canvas-host/a2ui/.bundle.hash"
+
+INPUT_PATHS=(
+  "$ROOT_DIR/package.json"
+  "$ROOT_DIR/pnpm-lock.yaml"
+  "$ROOT_DIR/vendor/a2ui/renderers/lit"
+  "$ROOT_DIR/apps/shared/ClawdisKit/Tools/CanvasA2UI"
+)
+
+collect_files() {
+  local path
+  for path in "${INPUT_PATHS[@]}"; do
+    if [[ -d "$path" ]]; then
+      find "$path" -type f -print0
+    else
+      printf '%s\0' "$path"
+    fi
+  done
+}
+
+compute_hash() {
+  collect_files \
+    | LC_ALL=C sort -z \
+    | xargs -0 shasum -a 256 \
+    | shasum -a 256 \
+    | awk '{print $1}'
+}
+
+current_hash="$(compute_hash)"
+if [[ -f "$HASH_FILE" ]]; then
+  previous_hash="$(cat "$HASH_FILE")"
+  if [[ "$previous_hash" == "$current_hash" ]]; then
+    echo "A2UI bundle up to date; skipping."
+    exit 0
+  fi
+fi
+
+pnpm -s exec tsc -p vendor/a2ui/renderers/lit/tsconfig.json
+rolldown -c apps/shared/ClawdisKit/Tools/CanvasA2UI/rolldown.config.mjs
+
+echo "$current_hash" > "$HASH_FILE"