langchain-ai/langchainjs @langchain/core@1.1.48 on GitHub

#10832 1b24369 Thanks @info-arnav! - fix(core, openrouter): make CJS default re-exports callable
#10666 2bb55b0 Thanks @hnustwjj! - feat(openrouter): surface reasoning content as v1 standard content blocks
convertOpenRouterResponseToBaseMessage and
convertOpenRouterDeltaToBaseMessageChunk now copy OpenRouter's
reasoning (flat string) and reasoning_details (structured array) fields
onto additional_kwargs.reasoning_content / additional_kwargs.reasoning_details.
A new ChatOpenRouterTranslator is registered in @langchain/core under
the "openrouter" provider key so AIMessage.contentBlocks emits standard
{type: "reasoning"} blocks alongside text and tool calls.
Previously, reasoning text returned by reasoning-capable models routed
through OpenRouter (DeepSeek R1, Minimax M2, Claude extended thinking,
o-series, etc.) was silently dropped: only the reasoning_tokens count
was preserved via usage_metadata. Consumers using standard content blocks
(including the frontend agent UI patterns shown in the docs) could not
display the model's chain of thought.
#10918 3999fab Thanks @christian-bromann! - fix(openai): stream custom tool calls through Responses API chunks