diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript01.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript01.luau
new file mode 100644
index 00000000..06e0c946
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript01.luau
@@ -0,0 +1,2 @@
+local BatchScript01 = {}
+return BatchScript01
diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript02.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript02.luau
new file mode 100644
index 00000000..909a59bd
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript02.luau
@@ -0,0 +1,2 @@
+local BatchScript02 = {}
+return BatchScript02
diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript03.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript03.luau
new file mode 100644
index 00000000..94d767ad
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript03.luau
@@ -0,0 +1,2 @@
+local BatchScript03 = {}
+return BatchScript03
diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript04.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript04.luau
new file mode 100644
index 00000000..77f95530
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript04.luau
@@ -0,0 +1,2 @@
+local BatchScript04 = {}
+return BatchScript04
diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript05.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript05.luau
new file mode 100644
index 00000000..e9cf8932
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript05.luau
@@ -0,0 +1,2 @@
+local BatchScript05 = {}
+return BatchScript05
diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript06.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript06.luau
new file mode 100644
index 00000000..96e56c10
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript06.luau
@@ -0,0 +1,2 @@
+local BatchScript06 = {}
+return BatchScript06
diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript07.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript07.luau
new file mode 100644
index 00000000..89fc6ec8
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript07.luau
@@ -0,0 +1,2 @@
+local BatchScript07 = {}
+return BatchScript07
diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript08.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript08.luau
new file mode 100644
index 00000000..026fa1f2
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript08.luau
@@ -0,0 +1,2 @@
+local BatchScript08 = {}
+return BatchScript08
diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript09.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript09.luau
new file mode 100644
index 00000000..57ccd37e
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript09.luau
@@ -0,0 +1,2 @@
+local BatchScript09 = {}
+return BatchScript09
diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript10.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript10.luau
new file mode 100644
index 00000000..9a2dd32d
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript10.luau
@@ -0,0 +1,2 @@
+local BatchScript10 = {}
+return BatchScript10
diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript11.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript11.luau
new file mode 100644
index 00000000..8ea7033c
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript11.luau
@@ -0,0 +1,2 @@
+local BatchScript11 = {}
+return BatchScript11
diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript12.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript12.luau
new file mode 100644
index 00000000..0d25ddc1
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript12.luau
@@ -0,0 +1,2 @@
+local BatchScript12 = {}
+return BatchScript12
diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript13.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript13.luau
new file mode 100644
index 00000000..1fb0d90e
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript13.luau
@@ -0,0 +1,2 @@
+local BatchScript13 = {}
+return BatchScript13
diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript14.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript14.luau
new file mode 100644
index 00000000..de006942
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript14.luau
@@ -0,0 +1,2 @@
+local BatchScript14 = {}
+return BatchScript14
diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript15.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript15.luau
new file mode 100644
index 00000000..06a8adea
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript15.luau
@@ -0,0 +1,2 @@
+local BatchScript15 = {}
+return BatchScript15
diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript16.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript16.luau
new file mode 100644
index 00000000..9d7a9548
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript16.luau
@@ -0,0 +1,2 @@
+local BatchScript16 = {}
+return BatchScript16
diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript17.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript17.luau
new file mode 100644
index 00000000..203a88d4
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript17.luau
@@ -0,0 +1,2 @@
+local BatchScript17 = {}
+return BatchScript17
diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript18.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript18.luau
new file mode 100644
index 00000000..687ff57e
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript18.luau
@@ -0,0 +1,2 @@
+local BatchScript18 = {}
+return BatchScript18
diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript19.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript19.luau
new file mode 100644
index 00000000..c7ba3de9
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript19.luau
@@ -0,0 +1,2 @@
+local BatchScript19 = {}
+return BatchScript19
diff --git a/rojo-test/serve-tests/git_sync_defaults/src/BatchScript20.luau b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript20.luau
new file mode 100644
index 00000000..f4a27c68
--- /dev/null
+++ b/rojo-test/serve-tests/git_sync_defaults/src/BatchScript20.luau
@@ -0,0 +1,2 @@
+local BatchScript20 = {}
+return BatchScript20
diff --git a/src/change_processor.rs b/src/change_processor.rs
index 4a27b907..c04fc14d 100644
--- a/src/change_processor.rs
+++ b/src/change_processor.rs
@@ -1013,6 +1013,7 @@ impl JobThreadContext {
             removed_instances: patch_set.removed_instances,
             updated_instances: Vec::new(),
             stage_ids: HashSet::new(),
+            stage_paths: Vec::new(),
         };
 
         let applied = apply_patch_set(&mut tree, structural_patch);
@@ -1027,7 +1028,7 @@ impl JobThreadContext {
         );
     }
 
-    fn handle_tree_event(&self, patch_set: PatchSet) {
+    fn handle_tree_event(&self, mut patch_set: PatchSet) {
         // Log incoming patch summary at debug level
         log::debug!(
             "Processing client patch: {} removed, {} added, {} updated",
@@ -1308,6 +1309,10 @@ impl JobThreadContext {
             // Applied after the PatchSet to keep metadata in sync.
             let mut metadata_updates: Vec<(Ref, PathBuf)> = Vec::new();
 
+            // Paths to stage via git add after all writes complete.
+            // Starts with pre-resolved paths from api.rs, then Source writes are appended.
+            let mut pending_stage_paths = std::mem::take(&mut patch_set.stage_paths);
+
             for update in &patch_set.updated_instances {
                 let id = update.id;
 
@@ -1821,12 +1826,7 @@ impl JobThreadContext {
                                             err
                                         );
                                     } else if patch_set.stage_ids.contains(&id) {
-                                        if let Some(ref repo_root) = self.git_repo_root {
-                                            crate::git::git_add(
-                                                repo_root,
-                                                std::slice::from_ref(write_path),
-                                            );
-                                        }
+                                        pending_stage_paths.push(write_path.clone());
                                     }
                                 } else {
                                     log::warn!("Cannot change Source to non-string value.");
@@ -1898,6 +1898,14 @@ impl JobThreadContext {
                 }
             }
 
+            // Consolidated git staging: one git_add call for all paths
+            // (pre-resolved from api.rs + Source writes from this function).
+            if !pending_stage_paths.is_empty() {
+                if let Some(ref repo_root) = self.git_repo_root {
+                    crate::git::git_add(repo_root, &pending_stage_paths);
+                }
+            }
+
             applied
         };
 
diff --git a/src/snapshot/patch.rs b/src/snapshot/patch.rs
index 7a4195ea..235ed12d 100644
--- a/src/snapshot/patch.rs
+++ b/src/snapshot/patch.rs
@@ -24,6 +24,12 @@ pub struct PatchSet {
     /// Populated from WriteRequest.stage_ids, consumed by change_processor.
     #[serde(default, skip)]
     pub stage_ids: HashSet<Ref>,
+    /// Pre-resolved filesystem paths to stage via git add.
+    /// Populated by api.rs (for files already on disk), consumed by change_processor
+    /// together with any Source write paths from stage_ids.
+    /// All staging is consolidated into a single git_add call to avoid index.lock races.
+    #[serde(default, skip)]
+    pub stage_paths: Vec<std::path::PathBuf>,
 }
 
 impl PatchSet {
@@ -33,6 +39,7 @@ impl PatchSet {
             added_instances: Vec::new(),
             updated_instances: Vec::new(),
             stage_ids: HashSet::new(),
+            stage_paths: Vec::new(),
         }
     }
 }
diff --git a/src/web/api.rs b/src/web/api.rs
index 0f1ed75a..380873f5 100644
--- a/src/web/api.rs
+++ b/src/web/api.rs
@@ -764,15 +764,10 @@ impl ApiService {
                 added_instances,
                 updated_instances,
                 stage_ids,
+                stage_paths: paths_to_stage,
             })
             .unwrap();
 
-        if let Some(repo_root) = self.serve_session.git_repo_root() {
-            if !paths_to_stage.is_empty() {
-                crate::git::git_add(repo_root, &paths_to_stage);
-            }
-        }
-
         msgpack_ok(WriteResponse { session_id })
     }
 
diff --git a/tests/tests/git_sync_defaults.rs b/tests/tests/git_sync_defaults.rs
index c5f2e92f..fd37c11e 100644
--- a/tests/tests/git_sync_defaults.rs
+++ b/tests/tests/git_sync_defaults.rs
@@ -690,3 +690,212 @@ fn init_style_script_staging_targets_init_file() {
         );
     }
 }
+
+// ===========================================================================
+// Batch staging: many files in a single write request
+// ===========================================================================
+
+const BATCH_SCRIPT_COUNT: usize = 20;
+
+fn batch_script_name(i: usize) -> String {
+    format!("BatchScript{:02}", i)
+}
+
+fn batch_script_rel_path(i: usize) -> String {
+    format!("src/{}.luau", batch_script_name(i))
+}
+
+#[test]
+fn batch_stage_20_files_no_index_lock_race() {
+    let mut session = TestServeSession::new_with_git("git_sync_defaults", |path| {
+        git_commit_all(path, "initial commit");
+        for i in 1..=BATCH_SCRIPT_COUNT {
+            fs::write(
+                path.join(batch_script_rel_path(i)),
+                format!("-- modified {}\nreturn {{}}\n", i),
+            )
+            .unwrap();
+        }
+    });
+    let info = session.wait_to_come_online();
+    let read = session.get_api_read(info.root_instance_id).unwrap();
+
+    let mut stage_ids = Vec::new();
+    for i in 1..=BATCH_SCRIPT_COUNT {
+        if let Some((id, _)) = find_instance_by_name(&read.instances, &batch_script_name(i)) {
+            stage_ids.push(id);
+        }
+    }
+    assert!(
+        stage_ids.len() >= BATCH_SCRIPT_COUNT,
+        "Should find all {} batch scripts, found {}",
+        BATCH_SCRIPT_COUNT,
+        stage_ids.len()
+    );
+
+    let write_request = WriteRequest {
+        session_id: info.session_id,
+        removed: vec![],
+        added: HashMap::new(),
+        updated: vec![],
+        stage_ids,
+    };
+    session.post_api_write(&write_request).unwrap();
+    thread::sleep(Duration::from_millis(1500));
+
+    for i in 1..=BATCH_SCRIPT_COUNT {
+        assert!(
+            git_is_staged(session.path(), &batch_script_rel_path(i)),
+            "{} should be staged",
+            batch_script_name(i)
+        );
+    }
+}
+
+#[test]
+fn batch_source_write_20_files_all_staged() {
+    let mut session = TestServeSession::new_with_git("git_sync_defaults", |path| {
+        git_commit_all(path, "initial commit");
+    });
+    let info = session.wait_to_come_online();
+    let read = session.get_api_read(info.root_instance_id).unwrap();
+
+    let mut updates = Vec::new();
+    let mut stage_ids = Vec::new();
+    for i in 1..=BATCH_SCRIPT_COUNT {
+        if let Some((id, _)) = find_instance_by_name(&read.instances, &batch_script_name(i)) {
+            let mut props = UstrMap::default();
+            props.insert(
+                ustr("Source"),
+                Some(Variant::String(format!(
+                    "-- batch pull {}\nreturn {{}}\n",
+                    i
+                ))),
+            );
+            updates.push(InstanceUpdate {
+                id,
+                changed_name: None,
+                changed_class_name: None,
+                changed_properties: props,
+                changed_metadata: None,
+            });
+            stage_ids.push(id);
+        }
+    }
+    assert!(
+        updates.len() >= BATCH_SCRIPT_COUNT,
+        "Should find all {} batch scripts, found {}",
+        BATCH_SCRIPT_COUNT,
+        updates.len()
+    );
+
+    let write_request = WriteRequest {
+        session_id: info.session_id,
+        removed: vec![],
+        added: HashMap::new(),
+        updated: updates,
+        stage_ids,
+    };
+    session.post_api_write(&write_request).unwrap();
+    thread::sleep(Duration::from_millis(2000));
+
+    for i in 1..=BATCH_SCRIPT_COUNT {
+        let rel = batch_script_rel_path(i);
+        assert!(
+            git_is_staged(session.path(), &rel),
+            "{} should be staged after batch Source write",
+            batch_script_name(i)
+        );
+        let content = fs::read_to_string(session.path().join(&rel)).unwrap();
+        assert!(
+            content.contains(&format!("batch pull {}", i)),
+            "{} should have new content on disk",
+            batch_script_name(i)
+        );
+    }
+}
+
+#[test]
+fn batch_mixed_stage_and_source_write() {
+    let mut session = TestServeSession::new_with_git("git_sync_defaults", |path| {
+        git_commit_all(path, "initial commit");
+        // Modify the first 10 files on disk (push-accepted: already on disk, just stage)
+        for i in 1..=10 {
+            fs::write(
+                path.join(batch_script_rel_path(i)),
+                format!("-- push modified {}\nreturn {{}}\n", i),
+            )
+            .unwrap();
+        }
+    });
+    let info = session.wait_to_come_online();
+    let read = session.get_api_read(info.root_instance_id).unwrap();
+
+    let mut updates = Vec::new();
+    let mut stage_ids = Vec::new();
+
+    // Files 1-10: push-accepted (already modified on disk, just stage)
+    for i in 1..=10 {
+        if let Some((id, _)) = find_instance_by_name(&read.instances, &batch_script_name(i)) {
+            stage_ids.push(id);
+        }
+    }
+
+    // Files 11-20: pull-accepted (Source write + stage)
+    for i in 11..=BATCH_SCRIPT_COUNT {
+        if let Some((id, _)) = find_instance_by_name(&read.instances, &batch_script_name(i)) {
+            let mut props = UstrMap::default();
+            props.insert(
+                ustr("Source"),
+                Some(Variant::String(format!(
+                    "-- pull source {}\nreturn {{}}\n",
+                    i
+                ))),
+            );
+            updates.push(InstanceUpdate {
+                id,
+                changed_name: None,
+                changed_class_name: None,
+                changed_properties: props,
+                changed_metadata: None,
+            });
+            stage_ids.push(id);
+        }
+    }
+
+    assert!(
+        stage_ids.len() >= BATCH_SCRIPT_COUNT,
+        "Should have {} stage_ids, got {}",
+        BATCH_SCRIPT_COUNT,
+        stage_ids.len()
+    );
+
+    let write_request = WriteRequest {
+        session_id: info.session_id,
+        removed: vec![],
+        added: HashMap::new(),
+        updated: updates,
+        stage_ids,
+    };
+    session.post_api_write(&write_request).unwrap();
+    thread::sleep(Duration::from_millis(2000));
+
+    // All 20 files should be staged
+    for i in 1..=BATCH_SCRIPT_COUNT {
+        assert!(
+            git_is_staged(session.path(), &batch_script_rel_path(i)),
+            "{} should be staged in mixed batch",
+            batch_script_name(i)
+        );
+    }
+
+    // Files 11-20 should have the new pull content
+    for i in 11..=BATCH_SCRIPT_COUNT {
+        let content = fs::read_to_string(session.path().join(batch_script_rel_path(i))).unwrap();
+        assert!(
+            content.contains(&format!("pull source {}", i)),
+            "{} should have pull content on disk",
+            batch_script_name(i)
+        );
+    }
+}