langchain-ai/langchainjs @langchain/openai@1.6.2 on GitHub

#11707 4109812 Thanks @richardscarrott! - feat(openai): support additional_tools on the Responses API. An additional_tools block on a SystemMessage, either bare in content or wrapped in a non_standard block, is sent verbatim as a top-level input item preceding the message.
additional_tools cannot work anywhere else, so it now throws instead of being dropped: on Chat Completions (set useResponsesApi: true), or on any message other than a SystemMessage. Assistant messages are exempt.
#11707 4109812 Thanks @richardscarrott! - fix(openai): accept non_standard-wrapped configuration_update and mcp_approval_response blocks. Previously only a bare block in content was hoisted to a top-level Responses API input item; a wrapped block, or one on a message built with contentBlocks, was silently dropped. Chat Completions now also sends the payload of a non_standard block rather than the wrapper.