diff --git a/core/shared/src/main/scala/works/iterative/core/FileRef.scala b/core/shared/src/main/scala/works/iterative/core/FileRef.scala
index 6d5a039..e32a0ac 100644
--- a/core/shared/src/main/scala/works/iterative/core/FileRef.scala
+++ b/core/shared/src/main/scala/works/iterative/core/FileRef.scala
@@ -15,6 +15,8 @@
       case s                           => s"${s / (1024 * 1024 * 1024)} GB"
     }
 
+  def withBase(url: String): FileRef = copy(url = url + this.url)
+
 object FileRef:
   def apply(
       name: String,