diff --git a/apps/web/src/routes/auth.ts b/apps/web/src/routes/auth.ts
index 7268be6..9b814fa 100644
--- a/apps/web/src/routes/auth.ts
+++ b/apps/web/src/routes/auth.ts
@@ -61,6 +61,7 @@ const COOKIE_OPTS = {
   secure: true,
   sameSite: "lax" as const,
   path: "/",
+  domain: ".pingql.com",  // share across pingql.com and api.pingql.com
   maxAge: 60 * 60 * 24 * 365, // 1 year
 };