LangSmith not capturing Bedrock Claude thinking blocks

[austinmw]

Hi, I'm currently using LangSmith with a langgraph.prebuilt.create_react_agent to capture traces. I'm using the Anthropic Claude Sonnet 4.5 model with interleaved thinking enabled. I am able to see user messages, assistant messages, tool calls and tool responses in the traces. However, I'm unable to see any thinking blocks in the traces. I know they exist because I see them in my Streamlit app.

Setup details:

• Tracing enabled via LANGCHAIN_TRACING_V2=true environment variable
• Model initialized with init_chat_model(model_id, model_provider="bedrock_converse", ...)
• Thinking enabled via additional_model_request_fields={"thinking": {"type": "enabled", "budget_tokens": N}}
• Agent created with create_react_agent(model, tools)

[angus-langchain]

@austinmw Can you please provide an MRE for this issue as its unclear whether its an issue with LangSmith, LangGraph, or Bedrock Claude

[angus-langchain]

closing as stale