diff --git a/runtime/build-webdav-media.sh b/runtime/build-webdav-media.sh
new file mode 100644
index 0000000..b2eecf2
--- /dev/null
+++ b/runtime/build-webdav-media.sh
@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+
+CONFIG_FILE="${PIWIGO_CONFIG:-}"
+[[ -n "$CONFIG_FILE" && -r "$CONFIG_FILE" ]] || { echo "WebDAV-Konfiguration fehlt: ${CONFIG_FILE:-<leer>}" >&2; exit 1; }
+
+# shellcheck source=/dev/null
+source "$CONFIG_FILE"
+
+: "${PIWIGO_ROOT:?PIWIGO_ROOT fehlt}"
+: "${CONNECTION_ID:?CONNECTION_ID fehlt}"
+: "${WEBDAV_BASE_URL:?WEBDAV_BASE_URL fehlt}"
+: "${WEBDAV_USER:?WEBDAV_USER fehlt}"
+: "${WEBDAV_PASSWORD_FILE:?WEBDAV_PASSWORD_FILE fehlt}"
+: "${WEBDAV_MAPPING_FILE:?WEBDAV_MAPPING_FILE fehlt}"
+: "${STATE_DIR:?STATE_DIR fehlt}"
+
+SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
+LOCK_FILE="$STATE_DIR/webdav-media.lock"
+mkdir -p -- "$STATE_DIR"
+exec 9>"$LOCK_FILE"
+flock -n 9 || exit 0
+
+PREVIEW_CACHE="$PIWIGO_ROOT/_data/bratonien-tools/nc-webdav-preview/connection-$CONNECTION_ID"
+
+php "$SCRIPT_DIR/lib/precache-webdav-previews.php" \
+    --mapping="$WEBDAV_MAPPING_FILE" \
+    --base-url="$WEBDAV_BASE_URL" \
+    --user="$WEBDAV_USER" \
+    --password-file="$WEBDAV_PASSWORD_FILE" \
+    --cache-dir="$PREVIEW_CACHE"
+
+php "$SCRIPT_DIR/lib/build-webdav-derivatives.php" \
+    --piwigo-root="$PIWIGO_ROOT" \
+    --connection-id="$CONNECTION_ID"