fix: only cache fees response if exclusive (#1267)

* feat: only cache fees response if exclusive

* fixup

api/suggested-fees.ts

@@ -333,7 +333,11 @@ const handler = async (
       responseJson,
     });
 
-    response.setHeader("Cache-Control", "s-maxage=10");
+    // Only cache response if exclusivity is not set. This prevents race conditions where
+    // cached exclusivity data is returned for multiple deposits.
+    if (exclusiveRelayer === sdk.constants.ZERO_ADDRESS) {
+      response.setHeader("Cache-Control", "s-maxage=10");
+    }
     response.status(200).json(responseJson);
   } catch (error) {
     return handleErrorCondition("suggested-fees", response, logger, error);