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 ff46a45..6d5a039 100644
--- a/core/shared/src/main/scala/works/iterative/core/FileRef.scala
+++ b/core/shared/src/main/scala/works/iterative/core/FileRef.scala
@@ -5,15 +5,22 @@
     name: String,
     url: String,
     fileType: Option[String],
-    size: Option[String]
-)
+    size: Option[Long]
+):
+  def sizeString: Option[String] =
+    size.map {
+      case s if s < 1024               => s"$s B"
+      case s if s < 1024 * 1024        => s"${s / 1024} KB"
+      case s if s < 1024 * 1024 * 1024 => s"${s / (1024 * 1024)} MB"
+      case s                           => s"${s / (1024 * 1024 * 1024)} GB"
+    }
 
 object FileRef:
   def apply(
       name: String,
       url: String,
       fileType: Option[String] = None,
-      size: Option[String] = None
+      size: Option[Long] = None
   ): Validated[FileRef] =
     for
       name <- Validated.nonEmptyString("file.name")(name)
@@ -24,5 +31,5 @@
       name: String,
       url: String,
       fileType: Option[String] = None,
-      size: Option[String] = None
+      size: Option[Long] = None
   ): FileRef = new FileRef(name, url, fileType, size)

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 ff46a45..6d5a039 100644
--- a/core/shared/src/main/scala/works/iterative/core/FileRef.scala
+++ b/core/shared/src/main/scala/works/iterative/core/FileRef.scala
@@ -5,15 +5,22 @@
     name: String,
     url: String,
     fileType: Option[String],
-    size: Option[String]
-)
+    size: Option[Long]
+):
+  def sizeString: Option[String] =
+    size.map {
+      case s if s < 1024               => s"$s B"
+      case s if s < 1024 * 1024        => s"${s / 1024} KB"
+      case s if s < 1024 * 1024 * 1024 => s"${s / (1024 * 1024)} MB"
+      case s                           => s"${s / (1024 * 1024 * 1024)} GB"
+    }
 
 object FileRef:
   def apply(
       name: String,
       url: String,
       fileType: Option[String] = None,
-      size: Option[String] = None
+      size: Option[Long] = None
   ): Validated[FileRef] =
     for
       name <- Validated.nonEmptyString("file.name")(name)
@@ -24,5 +31,5 @@
       name: String,
       url: String,
       fileType: Option[String] = None,
-      size: Option[String] = None
+      size: Option[Long] = None
   ): FileRef = new FileRef(name, url, fileType, size)
diff --git a/core/shared/src/main/scala/works/iterative/core/service/FileStore.scala b/core/shared/src/main/scala/works/iterative/core/service/FileStore.scala
index da934c1..10bdeb7 100644
--- a/core/shared/src/main/scala/works/iterative/core/service/FileStore.scala
+++ b/core/shared/src/main/scala/works/iterative/core/service/FileStore.scala
@@ -13,6 +13,7 @@
       file: Array[Byte],
       contentType: Option[String]
   ): Op[FileRef]
+  def load(url: String): Op[Option[Array[Byte]]]
 
 object FileStore:
   type Op[A] = URIO[FileStore, A]
@@ -24,3 +25,5 @@
       contentType: Option[String]
   ): Op[FileRef] =
     ZIO.serviceWithZIO(_.store(name, file, contentType))
+  def load(url: String): Op[Option[Array[Byte]]] =
+    ZIO.serviceWithZIO(_.load(url))

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 ff46a45..6d5a039 100644
--- a/core/shared/src/main/scala/works/iterative/core/FileRef.scala
+++ b/core/shared/src/main/scala/works/iterative/core/FileRef.scala
@@ -5,15 +5,22 @@
     name: String,
     url: String,
     fileType: Option[String],
-    size: Option[String]
-)
+    size: Option[Long]
+):
+  def sizeString: Option[String] =
+    size.map {
+      case s if s < 1024               => s"$s B"
+      case s if s < 1024 * 1024        => s"${s / 1024} KB"
+      case s if s < 1024 * 1024 * 1024 => s"${s / (1024 * 1024)} MB"
+      case s                           => s"${s / (1024 * 1024 * 1024)} GB"
+    }
 
 object FileRef:
   def apply(
       name: String,
       url: String,
       fileType: Option[String] = None,
-      size: Option[String] = None
+      size: Option[Long] = None
   ): Validated[FileRef] =
     for
       name <- Validated.nonEmptyString("file.name")(name)
@@ -24,5 +31,5 @@
       name: String,
       url: String,
       fileType: Option[String] = None,
-      size: Option[String] = None
+      size: Option[Long] = None
   ): FileRef = new FileRef(name, url, fileType, size)
diff --git a/core/shared/src/main/scala/works/iterative/core/service/FileStore.scala b/core/shared/src/main/scala/works/iterative/core/service/FileStore.scala
index da934c1..10bdeb7 100644
--- a/core/shared/src/main/scala/works/iterative/core/service/FileStore.scala
+++ b/core/shared/src/main/scala/works/iterative/core/service/FileStore.scala
@@ -13,6 +13,7 @@
       file: Array[Byte],
       contentType: Option[String]
   ): Op[FileRef]
+  def load(url: String): Op[Option[Array[Byte]]]
 
 object FileStore:
   type Op[A] = URIO[FileStore, A]
@@ -24,3 +25,5 @@
       contentType: Option[String]
   ): Op[FileRef] =
     ZIO.serviceWithZIO(_.store(name, file, contentType))
+  def load(url: String): Op[Option[Array[Byte]]] =
+    ZIO.serviceWithZIO(_.load(url))
diff --git a/core/shared/src/main/scala/works/iterative/core/service/impl/InMemoryFileStore.scala b/core/shared/src/main/scala/works/iterative/core/service/impl/InMemoryFileStore.scala
index e1c8b28..66ad66b 100644
--- a/core/shared/src/main/scala/works/iterative/core/service/impl/InMemoryFileStore.scala
+++ b/core/shared/src/main/scala/works/iterative/core/service/impl/InMemoryFileStore.scala
@@ -16,4 +16,6 @@
           contentType: Option[String]
       ): Op[FileRef] =
         ZIO.succeed(FileRef.unsafe(name, "#"))
+      override def load(url: String): Op[Option[Array[Byte]]] =
+        ZIO.succeed(None)
   }

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 ff46a45..6d5a039 100644
--- a/core/shared/src/main/scala/works/iterative/core/FileRef.scala
+++ b/core/shared/src/main/scala/works/iterative/core/FileRef.scala
@@ -5,15 +5,22 @@
     name: String,
     url: String,
     fileType: Option[String],
-    size: Option[String]
-)
+    size: Option[Long]
+):
+  def sizeString: Option[String] =
+    size.map {
+      case s if s < 1024               => s"$s B"
+      case s if s < 1024 * 1024        => s"${s / 1024} KB"
+      case s if s < 1024 * 1024 * 1024 => s"${s / (1024 * 1024)} MB"
+      case s                           => s"${s / (1024 * 1024 * 1024)} GB"
+    }
 
 object FileRef:
   def apply(
       name: String,
       url: String,
       fileType: Option[String] = None,
-      size: Option[String] = None
+      size: Option[Long] = None
   ): Validated[FileRef] =
     for
       name <- Validated.nonEmptyString("file.name")(name)
@@ -24,5 +31,5 @@
       name: String,
       url: String,
       fileType: Option[String] = None,
-      size: Option[String] = None
+      size: Option[Long] = None
   ): FileRef = new FileRef(name, url, fileType, size)
diff --git a/core/shared/src/main/scala/works/iterative/core/service/FileStore.scala b/core/shared/src/main/scala/works/iterative/core/service/FileStore.scala
index da934c1..10bdeb7 100644
--- a/core/shared/src/main/scala/works/iterative/core/service/FileStore.scala
+++ b/core/shared/src/main/scala/works/iterative/core/service/FileStore.scala
@@ -13,6 +13,7 @@
       file: Array[Byte],
       contentType: Option[String]
   ): Op[FileRef]
+  def load(url: String): Op[Option[Array[Byte]]]
 
 object FileStore:
   type Op[A] = URIO[FileStore, A]
@@ -24,3 +25,5 @@
       contentType: Option[String]
   ): Op[FileRef] =
     ZIO.serviceWithZIO(_.store(name, file, contentType))
+  def load(url: String): Op[Option[Array[Byte]]] =
+    ZIO.serviceWithZIO(_.load(url))
diff --git a/core/shared/src/main/scala/works/iterative/core/service/impl/InMemoryFileStore.scala b/core/shared/src/main/scala/works/iterative/core/service/impl/InMemoryFileStore.scala
index e1c8b28..66ad66b 100644
--- a/core/shared/src/main/scala/works/iterative/core/service/impl/InMemoryFileStore.scala
+++ b/core/shared/src/main/scala/works/iterative/core/service/impl/InMemoryFileStore.scala
@@ -16,4 +16,6 @@
           contentType: Option[String]
       ): Op[FileRef] =
         ZIO.succeed(FileRef.unsafe(name, "#"))
+      override def load(url: String): Op[Option[Array[Byte]]] =
+        ZIO.succeed(None)
   }
diff --git a/mongo/src/main/scala/works/iterative/mongo/MongoJsonRepository.scala b/mongo/src/main/scala/works/iterative/mongo/MongoJsonRepository.scala
index 90896ad..1ce1161 100644
--- a/mongo/src/main/scala/works/iterative/mongo/MongoJsonRepository.scala
+++ b/mongo/src/main/scala/works/iterative/mongo/MongoJsonRepository.scala
@@ -88,7 +88,7 @@
     toFilter: Criteria => Bson
 ):
 
-  def put(name: String, file: Array[Byte], metadata: Metadata): UIO[Unit] =
+  def put(name: String, file: Array[Byte], metadata: Metadata): UIO[String] =
     ZIO
       .fromFuture(_ =>
         bucket
@@ -99,7 +99,7 @@
           )
           .toFuture
       )
-      .unit
+      .map(_.toString())
       .orDie
 
   def find(id: String): UIO[Option[Array[Byte]]] =