Set start_time earlier

python/langsmith/client.py

@@ -1153,10 +1153,15 @@ def _run_transform(
             run_create: dict = run.dict()  # type: ignore
         else:
             run_create = cast(dict, run)
+        if not update and not run_create.get("start_time"):
+            # Should not hit here if you're using run_trees or other higher-order
+            # abstractions
+            run_create["start_time"] = datetime.datetime.now(datetime.timezone.utc)
         if "id" not in run_create:
             run_create["id"] = uuid.uuid4()
         elif isinstance(run_create["id"], str):
             run_create["id"] = uuid.UUID(run_create["id"])
+
         if "inputs" in run_create and run_create["inputs"] is not None:
             if copy:
                 run_create["inputs"] = ls_utils.deepish_copy(run_create["inputs"])
@@ -1165,8 +1170,6 @@ def _run_transform(
             if copy:
                 run_create["outputs"] = ls_utils.deepish_copy(run_create["outputs"])
             run_create["outputs"] = self._hide_run_outputs(run_create["outputs"])
-        if not update and not run_create.get("start_time"):
-            run_create["start_time"] = datetime.datetime.now(datetime.timezone.utc)
 
         # Only retain LLM & Prompt manifests
         if "serialized" in run_create:

python/langsmith/run_trees.py

@@ -81,6 +81,8 @@ class Config:
     @root_validator(pre=True)
     def infer_defaults(cls, values: dict) -> dict:
         """Assign name to the run."""
+        if not values.get("start_time"):
+            values["start_time"] = datetime.now(timezone.utc)
         if values.get("name") is None and values.get("serialized") is not None:
             if "name" in values["serialized"]:
                 values["name"] = values["serialized"]["name"]

python/tests/unit_tests/test_client.py

@@ -972,6 +972,7 @@ def test_batch_ingest_run_retry_on_429(mock_raise_for_status):
                 "id": str(uuid.uuid4()),
                 "trace_id": str(uuid.uuid4()),
                 "dotted_order": str(uuid.uuid4()),
+                "start_time": datetime.now(tz=timezone.utc),
             }
         ],
     )