From 36d5e9511a96dbb0bb9f75f3a12c30df80dab993 Mon Sep 17 00:00:00 2001
From: Hussainbeam <88007126+SYED-M-HUSSAIN@users.noreply.github.com>
Date: Mon, 26 May 2025 12:20:09 +0500
Subject: [PATCH 1/2] fix(bedrock): return string content in
 ChatBedrockConverse streaming

---
 .../chat_models/bedrock_converse.py           | 21 ++++++++++---------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/libs/aws/langchain_aws/chat_models/bedrock_converse.py b/libs/aws/langchain_aws/chat_models/bedrock_converse.py
index 9695e26f..31a8ba1b 100644
--- a/libs/aws/langchain_aws/chat_models/bedrock_converse.py
+++ b/libs/aws/langchain_aws/chat_models/bedrock_converse.py
@@ -1022,9 +1022,9 @@ def _parse_stream_event(event: Dict[str, Any]) -> Optional[BaseMessageChunk]:
     if "messageStart" in event:
         # TODO: needed?
         return (
-            AIMessageChunk(content=[])
+            AIMessageChunk(content="")
             if event["messageStart"]["role"] == "assistant"
-            else HumanMessageChunk(content=[])
+            else HumanMessageChunk(content="")
         )
     elif "contentBlockStart" in event:
         block = {
@@ -1041,7 +1041,9 @@ def _parse_stream_event(event: Dict[str, Any]) -> Optional[BaseMessageChunk]:
                     index=event["contentBlockStart"]["contentBlockIndex"],
                 )
             )
-        return AIMessageChunk(content=[block], tool_call_chunks=tool_call_chunks)
+        # Apply the same content formatting as _parse_response
+        content = _str_if_single_text_block([block])
+        return AIMessageChunk(content=content, tool_call_chunks=tool_call_chunks)
     elif "contentBlockDelta" in event:
         block = {
             **_bedrock_to_lc([event["contentBlockDelta"]["delta"]])[0],
@@ -1057,19 +1059,19 @@ def _parse_stream_event(event: Dict[str, Any]) -> Optional[BaseMessageChunk]:
                     index=event["contentBlockDelta"]["contentBlockIndex"],
                 )
             )
-        return AIMessageChunk(content=[block], tool_call_chunks=tool_call_chunks)
+        # Apply the same content formatting as _parse_response
+        content = _str_if_single_text_block([block])
+        return AIMessageChunk(content=content, tool_call_chunks=tool_call_chunks)
     elif "contentBlockStop" in event:
         # TODO: needed?
-        return AIMessageChunk(
-            content=[{"index": event["contentBlockStop"]["contentBlockIndex"]}]
-        )
+        return AIMessageChunk(content="")
     elif "messageStop" in event:
         # TODO: snake case response metadata?
-        return AIMessageChunk(content=[], response_metadata=event["messageStop"])
+        return AIMessageChunk(content="", response_metadata=event["messageStop"])
     elif "metadata" in event:
         usage = _extract_usage_metadata(event["metadata"])
         return AIMessageChunk(
-            content=[], response_metadata=event["metadata"], usage_metadata=usage
+            content="", response_metadata=event["metadata"], usage_metadata=usage
         )
     elif "Exception" in list(event.keys())[0]:
         name, info = list(event.items())[0]
@@ -1079,7 +1081,6 @@ def _parse_stream_event(event: Dict[str, Any]) -> Optional[BaseMessageChunk]:
     else:
         raise ValueError(f"Received unsupported stream event:\n\n{event}")
 
-
 def _format_data_content_block(block: dict) -> dict:
     """Format standard data content block to format expected by Converse API."""
     if block["type"] == "image":

From ebec1d510a5cd1e8da9fc1d7a0b34969ee78934f Mon Sep 17 00:00:00 2001
From: Hussainbeam <88007126+SYED-M-HUSSAIN@users.noreply.github.com>
Date: Tue, 27 May 2025 15:27:56 +0500
Subject: [PATCH 2/2] This approach addresses @blanketspy99's concern while
 still fixing the original consistency issue. It's a more robust solution that
 considers both current and future use cases.

---
 .../chat_models/bedrock_converse.py            | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/libs/aws/langchain_aws/chat_models/bedrock_converse.py b/libs/aws/langchain_aws/chat_models/bedrock_converse.py
index 31a8ba1b..e7309539 100644
--- a/libs/aws/langchain_aws/chat_models/bedrock_converse.py
+++ b/libs/aws/langchain_aws/chat_models/bedrock_converse.py
@@ -1041,9 +1041,14 @@ def _parse_stream_event(event: Dict[str, Any]) -> Optional[BaseMessageChunk]:
                     index=event["contentBlockStart"]["contentBlockIndex"],
                 )
             )
-        # Apply the same content formatting as _parse_response
-        content = _str_if_single_text_block([block])
+            # Keep tool calls as list to preserve type information
+            content = [block]
+        else:
+            # Convert text content to string for consistency with other LangChain models
+            content = _str_if_single_text_block([block])
+        
         return AIMessageChunk(content=content, tool_call_chunks=tool_call_chunks)
+        
     elif "contentBlockDelta" in event:
         block = {
             **_bedrock_to_lc([event["contentBlockDelta"]["delta"]])[0],
@@ -1059,9 +1064,14 @@ def _parse_stream_event(event: Dict[str, Any]) -> Optional[BaseMessageChunk]:
                     index=event["contentBlockDelta"]["contentBlockIndex"],
                 )
             )
-        # Apply the same content formatting as _parse_response
-        content = _str_if_single_text_block([block])
+            # Keep tool calls as list to preserve type information
+            content = [block]
+        else:
+            # Convert text content to string for consistency with other LangChain models
+            content = _str_if_single_text_block([block])
+        
         return AIMessageChunk(content=content, tool_call_chunks=tool_call_chunks)
+        
     elif "contentBlockStop" in event:
         # TODO: needed?
         return AIMessageChunk(content="")