diff --git a/portkey_ai/langchain/portkey_langchain_callback_handler.py b/portkey_ai/langchain/portkey_langchain_callback_handler.py
index c6a1d163..945f758d 100644
--- a/portkey_ai/langchain/portkey_langchain_callback_handler.py
+++ b/portkey_ai/langchain/portkey_langchain_callback_handler.py
@@ -5,7 +5,6 @@
 from uuid import UUID, uuid4
 from portkey_ai.api_resources.apis.logger import Logger
 import re
-from datetime import datetime
 
 try:
     from langchain_core.callbacks.base import BaseCallbackHandler
@@ -17,12 +16,13 @@ class LangchainCallbackHandler(BaseCallbackHandler):
     def __init__(
         self,
         api_key: str,
-        metadata: Optional[Dict[str, Any]] = {},
+        metadata: Optional[Dict[str, Any]] = None,
     ) -> None:
         super().__init__()
 
         self.api_key = api_key
-        self.metadata = metadata
+        self.metadata: Dict[str, Any] = metadata or {}
+        self.metadata.update({"_source": "Langchain", "_source_type": "Agent"})
 
         self.portkey_logger = Logger(api_key=api_key)
 
@@ -68,9 +68,11 @@ def on_llm_start(
         info_obj = self.start_event_information(
             run_id,
             parent_run_id,
-            "llm_start",
+            serialized.get("name", "llm"),
             self.global_trace_id,
             request_payload,
+            "llm",
+            tags,
             self.metadata,
         )
         self.event_map["llm_start_" + str(run_id)] = info_obj
@@ -88,8 +90,8 @@ def on_llm_end(
         """Run when LLM ends running."""
 
         start_time = self.event_map["llm_start_" + str(run_id)]["start_time"]
-        end_time = int(datetime.now().timestamp())
-        total_time = (end_time - start_time) * 1000
+        end_time = time.time()
+        total_time = f"{((end_time - start_time) * 1000):04.0f}"
 
         response_payload = self.on_llm_end_transformer(response, kwargs=kwargs)
         self.event_map["llm_start_" + str(run_id)]["response"] = response_payload
@@ -126,12 +128,13 @@ def on_chain_start(
         info_obj = self.start_event_information(
             run_id,
             parent_span_id,
-            "chain_start",
+            request_payload.get("name", "chain"),
             self.global_trace_id,
             request_payload,
+            "chain",
+            tags,
             self.metadata,
         )
-
         self.event_map["chain_start_" + str(run_id)] = info_obj
         pass
 
@@ -147,8 +150,8 @@ def on_chain_end(
         """Run when chain ends running."""
 
         start_time = self.event_map["chain_start_" + str(run_id)]["start_time"]
-        end_time = int(datetime.now().timestamp())
-        total_time = (end_time - start_time) * 1000
+        end_time = time.time()
+        total_time = f"{((end_time - start_time) * 1000):04.0f}"
 
         response_payload = self.on_chain_end_transformer(outputs)
 
@@ -185,9 +188,11 @@ def on_tool_start(
         info_obj = self.start_event_information(
             run_id,
             parent_run_id,
-            "tool_start",
+            request_payload.get("serialized", {}).get("name", "tool"),
             self.global_trace_id,
             request_payload,
+            "tool",
+            tags,
             self.metadata,
         )
         self.event_map["tool_start_" + str(run_id)] = info_obj
@@ -205,8 +210,8 @@ def on_tool_end(
         """Run when tool ends running."""
 
         start_time = self.event_map["tool_start_" + str(run_id)]["start_time"]
-        end_time = int(datetime.now().timestamp())
-        total_time = (end_time - start_time) * 1000
+        end_time = time.time()
+        total_time = f"{((end_time - start_time) * 1000):04.0f}"
 
         response_payload = self.on_tool_end_transformer(output)
         self.event_map["tool_start_" + str(run_id)]["response"] = response_payload
@@ -250,9 +255,20 @@ def start_event_information(
         span_name,
         trace_id,
         request_payload,
+        span_type,
+        tags,
         metadata=None,
     ):
-        start_time = int(datetime.now().timestamp())
+        start_time = time.time()
+        source_metadata = {}
+        portkey_metadata = {}
+        portkey_metadata.update(metadata)
+        if span_type:
+            source_metadata.update({"type": span_type})
+        if len(tags):
+            source_metadata.update({"tags": tags})
+        if source_metadata:
+            portkey_metadata.update({"source_metadata": json.dumps(source_metadata)})
         return {
             "span_id": str(span_id),
             "parent_span_id": str(parent_span_id),
@@ -260,7 +276,7 @@ def start_event_information(
             "trace_id": trace_id,
             "request": request_payload,
             "start_time": start_time,
-            "metadata": metadata,
+            "metadata": portkey_metadata,
         }
 
     def serialize(self, obj):