ChatBedrockConverse cannot handle Bedrock DeepSeek R1 response

[mesutgurlek]

Hi, I am trying to use Bedrock Deepseek R1 model via ChatBedrockConverse class, that wraps the boto3 Converse API.
Initially, I tested the related script in https://docs.aws.amazon.com/bedrock/latest/userguide/model-parameters-deepseek.html
It seems that, boto3 API returns unexpexted keys in the response json:

[{'text': '\n\n1. **"Levitating" - Dua Lipa ft. DaBaby**  \n2. **"Blinding Lights" - The Weeknd**  \n3. **"Rolling in the Deep" - Adele**'}, {'SDK_UNKNOWN_MEMBER': {'name': 'reasoningContent'}}]

The SDK_UNKNOWN_MEMBER key raises error in the _bedrock_to_lc function in the implementation:

langchain-aws/libs/aws/langchain_aws/chat_models/bedrock_converse.py

Lines 1250 to 1257 in 1b61a6f

	else:
	raise ValueError(
	"Unexpected content block type in content. Expected to have one of "
	"'text', 'tool_use', 'image', 'video, 'document', 'tool_result',"
	"'json', 'guard_content', or "
	"'reasoning_content' keys. Received:\n\n{block}"
	)
	return lc_content

I am also opening a ticket to AWS support but is there any way to handle in the langchain implementation ?

[michaelnchin]

SDK_UNKNOWN_MEMBER technically represents an error in the Converse API response, so we might be throwing an exception here intentionally.

In this case, the error is due to passing reasoningContent into the request, which isn't currently supported for DeepSeek on Converse API (see analysis here). I'm not yet certain if this is something we should explicitly handle on the LangChain side.

[michaelnchin]

Today's release (v0.2.16) added new provisions for passing DeepSeek reasoning blocks with ChatBedrockConverse - @mesutgurlek , could you try it out, and let us know if you are still having the same issue? If so, please provide a brief reproducible code sample.