Add data transfer middleware

functions/api/data-transfers/_middleware.ts

@@ -0,0 +1,17 @@
+export async function onRequest(context: RequestContext) {
+  const cookies = context.request.headers.get("cookie");
+
+  if (!cookies) return await context.next();
+
+  const cookieList = cookies.split("; ").map((cookie) => {
+    const [name, value] = cookie.split("=");
+
+    return { name, value };
+  });
+
+  const transferId = cookieList.find((cookie) => cookie.name === "__dtid");
+
+  if (transferId) context.data.data_transfer_id = transferId;
+
+  return await context.next();
+}