diff --git a/xet_data/src/processing/file_download_session.rs b/xet_data/src/processing/file_download_session.rs
index 8a8c70014..793ec6fc9 100644
--- a/xet_data/src/processing/file_download_session.rs
+++ b/xet_data/src/processing/file_download_session.rs
@@ -143,8 +143,14 @@ impl FileDownloadSession {
     ///
     /// This path does not acquire the session-level file download semaphore.
     #[instrument(skip_all, name = "FileDownloadSession::download_stream", fields(hash = file_info.hash()))]
-    pub fn download_stream(&self, file_info: &XetFileInfo, tracking_id: Ulid) -> Result<DownloadStream> {
-        let reconstructor = self.setup_reconstructor(file_info, None, tracking_id, None, None)?;
+    pub fn download_stream(
+        &self,
+        file_info: &XetFileInfo,
+        source_range: Option<Range<u64>>,
+        tracking_id: Ulid,
+    ) -> Result<DownloadStream> {
+        let file_range = source_range.map(|r| FileRange::new(r.start, r.end));
+        let reconstructor = self.setup_reconstructor(file_info, file_range, tracking_id, None, None)?;
         Ok(reconstructor.reconstruct_to_stream())
     }
 
@@ -437,7 +443,7 @@ mod tests {
                 let config = TranslatorConfig::local_config(&cas_path).unwrap();
                 let session = FileDownloadSession::new(config.into(), None).await.unwrap();
 
-                let mut stream = session.download_stream(&xfi, Ulid::new()).unwrap();
+                let mut stream = session.download_stream(&xfi, None, Ulid::new()).unwrap();
 
                 let mut collected = Vec::new();
                 while let Some(chunk) = stream.next().await.unwrap() {
@@ -464,7 +470,7 @@ mod tests {
                 let config = TranslatorConfig::local_config(&cas_path).unwrap();
                 let session = FileDownloadSession::new(config.into(), None).await.unwrap();
 
-                let stream = session.download_stream(&xfi, Ulid::new()).unwrap();
+                let stream = session.download_stream(&xfi, None, Ulid::new()).unwrap();
 
                 let collected = tokio::task::spawn_blocking(move || {
                     let mut stream = stream;
@@ -497,7 +503,7 @@ mod tests {
                 let config = TranslatorConfig::local_config(&cas_path).unwrap();
                 let session = FileDownloadSession::new(config.into(), None).await.unwrap();
 
-                let mut stream = session.download_stream(&xfi, Ulid::new()).unwrap();
+                let mut stream = session.download_stream(&xfi, None, Ulid::new()).unwrap();
 
                 // Drain all data
                 while stream.next().await.unwrap().is_some() {}
@@ -527,8 +533,8 @@ mod tests {
                 let config = TranslatorConfig::local_config(&cas_path).unwrap();
                 let session = FileDownloadSession::new(config.into(), None).await.unwrap();
 
-                let mut stream_a = session.download_stream(&xfi_a, Ulid::new()).unwrap();
-                let mut stream_b = session.download_stream(&xfi_b, Ulid::new()).unwrap();
+                let mut stream_a = session.download_stream(&xfi_a, None, Ulid::new()).unwrap();
+                let mut stream_b = session.download_stream(&xfi_b, None, Ulid::new()).unwrap();
 
                 let task_a = tokio::spawn(async move {
                     let mut buf = Vec::new();
@@ -571,7 +577,7 @@ mod tests {
                 let session = FileDownloadSession::new(config.into(), None).await.unwrap();
 
                 // Create and drop a stream without ever reading from it.
-                let stream = session.download_stream(&xfi, Ulid::new()).unwrap();
+                let stream = session.download_stream(&xfi, None, Ulid::new()).unwrap();
                 drop(stream);
                 tokio::task::yield_now().await;
 
@@ -600,7 +606,7 @@ mod tests {
 
                 // Repeatedly create, start, optionally read, and drop streams.
                 for i in 0..5u32 {
-                    let mut stream = session.download_stream(&xfi, Ulid::new()).unwrap();
+                    let mut stream = session.download_stream(&xfi, None, Ulid::new()).unwrap();
                     if i % 3 == 0 {
                         let _ = stream.next().await;
                     }
@@ -632,7 +638,7 @@ mod tests {
                 let session = FileDownloadSession::new(config.into(), None).await.unwrap();
 
                 // Read one chunk via blocking next() in a spawn_blocking, then drop.
-                let stream = session.download_stream(&xfi, Ulid::new()).unwrap();
+                let stream = session.download_stream(&xfi, None, Ulid::new()).unwrap();
 
                 tokio::task::spawn_blocking(move || {
                     let mut stream = stream;
@@ -668,7 +674,7 @@ mod tests {
                 let config = TranslatorConfig::local_config(&cas_path).unwrap();
                 let session = FileDownloadSession::new(config.into(), None).await.unwrap();
 
-                let mut stream = session.download_stream(&xfi, Ulid::new()).unwrap();
+                let mut stream = session.download_stream(&xfi, None, Ulid::new()).unwrap();
                 stream.cancel();
                 assert!(stream.next().await.unwrap().is_none());
                 assert!(stream.next().await.unwrap().is_none());
@@ -691,7 +697,7 @@ mod tests {
                 let config = TranslatorConfig::local_config(&cas_path).unwrap();
                 let session = FileDownloadSession::new(config.into(), None).await.unwrap();
 
-                let mut stream = session.download_stream(&xfi, Ulid::new()).unwrap();
+                let mut stream = session.download_stream(&xfi, None, Ulid::new()).unwrap();
                 let _ = stream.next().await.unwrap();
                 stream.cancel();
                 assert!(stream.next().await.unwrap().is_none());
diff --git a/xet_data/src/processing/test_utils.rs b/xet_data/src/processing/test_utils.rs
index 6ce51cff3..e6057f53b 100644
--- a/xet_data/src/processing/test_utils.rs
+++ b/xet_data/src/processing/test_utils.rs
@@ -309,7 +309,7 @@ impl HydrateDehydrateTest {
             let out_filename = self.dest_dir.join(entry.file_name());
 
             let xf: XetFileInfo = serde_json::from_reader(File::open(entry.path()).unwrap()).unwrap();
-            let mut stream = session.download_stream(&xf, Ulid::new()).unwrap();
+            let mut stream = session.download_stream(&xf, None, Ulid::new()).unwrap();
 
             let mut file = File::create(&out_filename).unwrap();
             while let Some(chunk) = stream.next().await.unwrap() {