diff --git a/python/langsmith/_internal/_background_thread.py b/python/langsmith/_internal/_background_thread.py
index 6647e87c9..4e2d8a266 100644
--- a/python/langsmith/_internal/_background_thread.py
+++ b/python/langsmith/_internal/_background_thread.py
@@ -18,6 +18,7 @@
 )
 
 from langsmith import schemas as ls_schemas
+from langsmith import utils as ls_utils
 from langsmith._internal._constants import (
     _AUTO_SCALE_DOWN_NEMPTY_TRIGGER,
     _AUTO_SCALE_UP_NTHREADS_LIMIT,
@@ -157,6 +158,21 @@ def _tracing_thread_handle_batch(
             tracing_queue.task_done()
 
 
+def get_size_limit_from_env() -> Optional[int]:
+    size_limit_str = ls_utils.get_env_var(
+        "BATCH_INGEST_SIZE_LIMIT",
+    )
+    if size_limit_str is not None:
+        try:
+            return int(size_limit_str)
+        except ValueError:
+            logger.warning(
+                f"Invalid value for BATCH_INGEST_SIZE_LIMIT: {size_limit_str}, "
+                "continuing with default"
+            )
+    return None
+
+
 def _ensure_ingest_config(
     info: ls_schemas.LangSmithInfo,
 ) -> ls_schemas.BatchIngestConfig:
@@ -173,6 +189,9 @@ def _ensure_ingest_config(
     try:
         if not info.batch_ingest_config:
             return default_config
+        env_size_limit = get_size_limit_from_env()
+        if env_size_limit is not None:
+            info.batch_ingest_config["size_limit"] = env_size_limit
         return info.batch_ingest_config
     except BaseException:
         return default_config