diff --git a/wrangler.data.jsonc b/wrangler.data.jsonc
index 1e00e85b0..604f49278 100644
--- a/wrangler.data.jsonc
+++ b/wrangler.data.jsonc
@@ -17,6 +17,10 @@
   // box Postgres, reached via Cloudflare Tunnel) to minimize the per-request DB round-trip,
   // not at the nearest edge to the client.
   "placement": { "mode": "smart" },
+  // This Worker owns an internal write path plus uncached Postgres read routes;
+  // keep it reachable only through the main Worker's DATA_API service binding.
+  "workers_dev": false,
+  "preview_urls": false,
   // Full observability — logs AND traces (matches the main Worker).
   "observability": {
     "enabled": true,