ai-agents-openai-compatibility-langchain-s-chatopenai-message-conversion-function-d0671767

THEN Modify _convert_dict_to_message and _convert_message_to_dict in langchain_openai to preserve all extra fields beyond the defined schema, mirroring the openai library's forward-compatible design. This allows new API fields or custom extensions to pass through without being silently discarded.

# Instead of manually mapping known fields, iterate over all keys and pass through unknown ones.
# For dict-to-message conversion, accept extra kwargs and store them in additional_kwargs or a custom attribute.
# For message-to-dict conversion, include all fields from the message's additional_kwargs and any extra attributes.