langchain

vlangchain-core==1.4.5 scope: langchain-core Feature

This release adds 1 notable feature for engineering teams evaluating rollout.

Published 8d AI Agents & Assistants

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Topics

agents ai ai-agents anthropic chatgpt deepagents

+11 more

enterprise gemini generative-ai langchain langgraph llm multiagent openai pydantic python typescript

Summary

AI summary

Tighten structured output model fallbacks and fix async tracer fallback in sync context.

Changes in this release

Type	Severity	Summary	CVE
Feature	Low	Adds validation of tool call chunks during streaming for standard tests. Adds validation of tool call chunks during streaming for standard tests. Source: llm_adapter@2026-06-11 Confidence: high	—
Bugfix	Medium	Fixes async tracer on_chat_model_start fallback in sync context. Fixes async tracer on_chat_model_start fallback in sync context. Source: llm_adapter@2026-06-11 Confidence: high	—
Bugfix	Low	Tightens structured output model fallbacks in langchain. Tightens structured output model fallbacks in langchain. Source: llm_adapter@2026-06-11 Confidence: high	—

Full changelog

Changes since langchain-core==1.4.4

release(core): 1.4.5 (#38056)
feat(standard-tests): validate tool call chunks during streaming (#34707)
fix(core): async tracer on_chat_model_start fallback in sync context (#35233)
fix(langchain): tighten structured output model fallbacks (#38042)

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Earlier breaking changes

vlangchain-core==1.4.0 Deletes schema items marked for removal in schemas.py
vlangchain-core==1.4.0 Deletes function_calling.py utils marked for removal
vlangchain-core==1.4.0 Deletes get_relevant_documents function from API
vlangchain-core==1.4.0 Deletes pydantic_v1 module entirely from codebase
vlangchain-core==1.4.0 Deletes BaseMemory module, moved to langchain-classic