diff --git a/crates/openshell-cli/src/main.rs b/crates/openshell-cli/src/main.rs
index d4a19c4bf..2e566be40 100644
--- a/crates/openshell-cli/src/main.rs
+++ b/crates/openshell-cli/src/main.rs
@@ -2664,20 +2664,26 @@ async fn main() -> Result<()> {
                     let dest_display = sandbox_dest.unwrap_or("~");
                     eprintln!("Uploading {} -> sandbox:{}", local.display(), dest_display);
                     if !no_git_ignore && let Ok((base_dir, files)) = run::git_sync_files(local) {
-                        run::sandbox_sync_up_files(
-                            &ctx.endpoint,
-                            &name,
-                            &base_dir,
-                            &files,
-                            local,
-                            sandbox_dest,
-                            &tls,
-                        )
-                        .await?;
-                        eprintln!("{} Upload complete", "✓".green().bold());
-                        return Ok(());
+                        if !files.is_empty() {
+                            run::sandbox_sync_up_files(
+                                &ctx.endpoint,
+                                &name,
+                                &base_dir,
+                                &files,
+                                local,
+                                sandbox_dest,
+                                &tls,
+                            )
+                            .await?;
+                            eprintln!("{} Upload complete", "✓".green().bold());
+                            return Ok(());
+                        }
+                        eprintln!(
+                            "{} .gitignore filtering excluded all files in {}; uploading unfiltered",
+                            "⚠".yellow().bold(),
+                            local.display(),
+                        );
                     }
-                    // Fallback: upload without git filtering
                     run::sandbox_sync_up(&ctx.endpoint, &name, local, sandbox_dest, &tls).await?;
                     eprintln!("{} Upload complete", "✓".green().bold());
                 }
diff --git a/crates/openshell-cli/src/run.rs b/crates/openshell-cli/src/run.rs
index 64145d883..36e1eb2c4 100644
--- a/crates/openshell-cli/src/run.rs
+++ b/crates/openshell-cli/src/run.rs
@@ -83,6 +83,7 @@ enum SandboxUploadPlan {
         files: Vec<String>,
     },
     Regular,
+    GitFilteredEmpty,
 }
 
 /// Convert a sandbox phase integer to a human-readable string.
@@ -2143,6 +2144,21 @@ pub async fn sandbox_create(
                         )
                         .await?;
                     }
+                    SandboxUploadPlan::GitFilteredEmpty => {
+                        eprintln!(
+                            "  {} .gitignore filtering excluded all files in {}; uploading unfiltered",
+                            "⚠".yellow().bold(),
+                            local.display(),
+                        );
+                        sandbox_sync_up(
+                            &effective_server,
+                            &sandbox_name,
+                            local,
+                            dest,
+                            &effective_tls,
+                        )
+                        .await?;
+                    }
                     SandboxUploadPlan::Regular => {
                         sandbox_sync_up(
                             &effective_server,
@@ -5804,6 +5820,9 @@ fn sandbox_upload_plan(local_path: &Path, git_ignore: bool) -> Result<SandboxUpl
         && !metadata.file_type().is_symlink()
         && let Ok((base_dir, files)) = git_sync_files(local_path)
     {
+        if files.is_empty() {
+            return Ok(SandboxUploadPlan::GitFilteredEmpty);
+        }
         return Ok(SandboxUploadPlan::GitAware { base_dir, files });
     }
 
@@ -8364,6 +8383,25 @@ mod tests {
         assert_eq!(plan, super::SandboxUploadPlan::Regular);
     }
 
+    #[test]
+    fn sandbox_upload_plan_falls_back_when_all_files_gitignored() {
+        let tmpdir = tempfile::tempdir().expect("create tmpdir");
+        let repo = tmpdir.path().join("repo");
+        fs::create_dir_all(repo.join("runs")).expect("create repo");
+        init_git_repo(&repo);
+        fs::write(repo.join(".gitignore"), "runs/\n").expect("write .gitignore");
+        fs::write(repo.join("runs/test.json"), r#"{"key":"value"}"#).expect("write test.json");
+
+        let plan =
+            sandbox_upload_plan(&repo.join("runs"), true).expect("upload plan should succeed");
+
+        assert_eq!(
+            plan,
+            super::SandboxUploadPlan::GitFilteredEmpty,
+            "gitignored directory should fall back with GitFilteredEmpty"
+        );
+    }
+
     #[test]
     fn git_sync_files_ignores_inherited_git_env() {
         let _lock = TEST_ENV_LOCK
diff --git a/docs/sandboxes/manage-sandboxes.mdx b/docs/sandboxes/manage-sandboxes.mdx
index 0db6d7678..0c0809730 100644
--- a/docs/sandboxes/manage-sandboxes.mdx
+++ b/docs/sandboxes/manage-sandboxes.mdx
@@ -337,6 +337,13 @@ openshell sandbox create --upload ./src:/workspace/src --upload ./config:/worksp
 
 </Note>
 
+By default, uploads inside a Git repository respect `.gitignore` rules so that
+build artifacts, dependency caches, and other ignored files are not transferred.
+If `.gitignore` filtering excludes every file in the upload path, the CLI falls
+back to an unfiltered upload and prints a warning. Pass `--no-git-ignore` to
+opt into unfiltered uploads explicitly, upload a path outside the Git work
+tree, or force-add the intended files if they should remain Git-aware.
+
 ## Delete Sandboxes
 
 Deleting a sandbox stops all processes, releases resources, and purges injected credentials.
diff --git a/e2e/rust/tests/sync.rs b/e2e/rust/tests/sync.rs
index a42447865..a57793a74 100644
--- a/e2e/rust/tests/sync.rs
+++ b/e2e/rust/tests/sync.rs
@@ -73,7 +73,10 @@ async fn sandbox_file_upload_download_round_trip() {
     // Verify nested file.
     let nested = fs::read_to_string(download_dir.join("subdir/nested.txt"))
         .expect("read subdir/nested.txt after download");
-    assert_eq!(nested, "nested-content", "subdir/nested.txt content mismatch");
+    assert_eq!(
+        nested, "nested-content",
+        "subdir/nested.txt content mismatch"
+    );
 
     // ---------------------------------------------------------------
     // Step 4 — Large-file round-trip (~512 KiB) to exercise multi-chunk
@@ -112,7 +115,8 @@ async fn sandbox_file_upload_download_round_trip() {
         .await
         .expect("download large file");
 
-    let actual_data = fs::read(large_down.join("large.bin")).expect("read large.bin after download");
+    let actual_data =
+        fs::read(large_down.join("large.bin")).expect("read large.bin after download");
     let actual_hash = {
         let mut hasher = Sha256::new();
         hasher.update(&actual_data);
@@ -152,8 +156,8 @@ async fn sandbox_file_upload_download_round_trip() {
         .await
         .expect("download single file");
 
-    let single_content = fs::read_to_string(single_down.join("single.txt"))
-        .expect("read single.txt after download");
+    let single_content =
+        fs::read_to_string(single_down.join("single.txt")).expect("read single.txt after download");
     assert_eq!(
         single_content, "single-file-payload",
         "single.txt content mismatch"
@@ -364,7 +368,11 @@ async fn sandbox_download_file_only() {
             .expect("sandbox create --keep");
 
     guard
-        .exec(&["sh", "-c", "printf greeting-payload > /sandbox/greeting.txt"])
+        .exec(&[
+            "sh",
+            "-c",
+            "printf greeting-payload > /sandbox/greeting.txt",
+        ])
         .await
         .expect("seed greeting.txt inside the sandbox");
 
@@ -436,7 +444,9 @@ async fn sandbox_download_directory_only() {
 /// match the short markers individually instead.
 fn assert_resolves_outside_workspace(err: &str, label: &str) {
     assert!(
-        err.contains("resolves to") && err.contains("outside the") && err.contains("sandbox workspace"),
+        err.contains("resolves to")
+            && err.contains("outside the")
+            && err.contains("sandbox workspace"),
         "expected resolves-outside-workspace error for {label}, got: {err}"
     );
 }
@@ -543,3 +553,90 @@ async fn sandbox_download_handles_dash_leading_basename() {
 
     guard.cleanup().await;
 }
+
+/// Regression for #1778: uploading a directory whose contents are entirely
+/// excluded by `.gitignore` must still transfer the files instead of
+/// silently reporting success with zero bytes sent.
+///
+/// Reproduces the reported workflow: download files from a sandbox into a
+/// local git repo where the target directory is gitignored, then re-upload
+/// to the same sandbox at a different path.
+#[tokio::test]
+async fn upload_gitignored_directory_falls_back_to_unfiltered() {
+    let mut guard =
+        SandboxGuard::create_keep(&["sh", "-c", "echo Ready && sleep infinity"], "Ready")
+            .await
+            .expect("sandbox create --keep");
+
+    // Seed a file inside the sandbox so we have something to download.
+    guard
+        .exec(&[
+            "sh",
+            "-c",
+            "mkdir -p /sandbox/runs && printf downloaded-payload > /sandbox/runs/test.json",
+        ])
+        .await
+        .expect("seed runs/test.json inside the sandbox");
+
+    // Download the file into a local git repo where `runs/` is gitignored.
+    let tmpdir = tempfile::tempdir().expect("create tmpdir");
+    let repo = tmpdir.path().join("repo");
+    fs::create_dir_all(&repo).expect("create repo dir");
+
+    let git_init = tokio::process::Command::new("git")
+        .args(["init"])
+        .current_dir(&repo)
+        .stdout(Stdio::null())
+        .stderr(Stdio::null())
+        .status()
+        .await
+        .expect("git init");
+    assert!(git_init.success(), "git init should succeed");
+
+    fs::write(repo.join(".gitignore"), "runs/\n").expect("write .gitignore");
+
+    let download_dest = repo.join("runs");
+    fs::create_dir_all(&download_dest).expect("create runs dir");
+    let download_str = download_dest.to_str().expect("download path is UTF-8");
+
+    guard
+        .download("/sandbox/runs/test.json", download_str)
+        .await
+        .expect("download runs/test.json");
+
+    let local_file = download_dest.join("test.json");
+    assert!(local_file.exists(), "downloaded file should exist locally");
+
+    // Re-upload the gitignored directory (without --no-git-ignore).
+    let upload_str = download_dest.to_str().expect("upload path is UTF-8");
+    let upload_output = guard
+        .upload_with_gitignore(upload_str, "/sandbox/reuploaded", &repo)
+        .await
+        .expect("upload gitignored directory");
+
+    assert!(
+        upload_output.contains(".gitignore filtering excluded all files"),
+        "expected fallback warning in upload output, got: {upload_output}"
+    );
+
+    // Download the re-uploaded file and verify it arrived.
+    let verify_dir = tmpdir.path().join("verify");
+    fs::create_dir_all(&verify_dir).expect("create verify dir");
+    let verify_str = verify_dir.to_str().expect("verify path is UTF-8");
+
+    guard
+        .download("/sandbox/reuploaded", verify_str)
+        .await
+        .expect("download reuploaded directory");
+
+    // The upload wraps contents under the source basename, so the file
+    // lands at verify/runs/test.json.
+    let reuploaded = fs::read_to_string(verify_dir.join("runs/test.json"))
+        .expect("reuploaded test.json should exist");
+    assert_eq!(
+        reuploaded, "downloaded-payload",
+        "reuploaded file content mismatch — gitignored directory was not uploaded"
+    );
+
+    guard.cleanup().await;
+}