langchain-ai/langchainjs @langchain/core@1.2.11

on GitHub

Patch Changes

• #11603 fec9cd8 Thanks @thushanth-bengre-langchain! - fix(core): build streaming llmOutput.tokenUsage from the fully-accumulated chunk instead of whichever individual chunk's usage_metadata arrived last

  Affects both core streaming paths — .stream()/.streamEvents() (_streamIterator) and .invoke()/.generate() when a streaming-preferring callback is attached (_generateWithCache's hasStreamingHandler branch). Previously, llmOutput.tokenUsage was overwritten by each chunk in turn, so only the last chunk carrying usage_metadata won — correct for providers that emit one cumulative total on a final chunk, but wrong for providers (e.g. @langchain/google, @langchain/anthropic) that emit usage_metadata as a per-chunk delta across multiple chunks, where the values must be summed.

  Note for provider authors: this assumes each streamed chunk's usage_metadata is either a per-chunk delta or appears only on a single final chunk. A provider that instead repeats a cumulative total on every chunk will now see it summed (and inflated) in llmOutput.tokenUsage, matching the existing behavior of the correctly-working message.usage_metadata field.

  Also fixes @langchain/google's invoke({streaming: true}) path (no streaming-preferring callback attached), where llmOutput was never populated at all.

• #11590 ffebdc2 Thanks @thushanth-bengre-langchain! - Fix OpenAI Responses API replay under Zero Data Retention when a response contains more than one reasoning item, for both v0 and v1. In v0, the default replay path now reuses response_metadata.output directly, preserving every reasoning item's id/encrypted_content in original order. In v1, AIMessage.contentBlocks (outputVersion: "v1") is fixed the same way. additional_kwargs.reasoning is unchanged.