Overview
What’s new in LangChain?​
The following features have been added during the development of 0.1.x:
- Better streaming support via the Event Streaming API.
 - Standardized tool calling support
 - A standardized interface for structuring output
 - @chain decorator to more easily create RunnableLambdas
 - https://python.langchain.com/docs/expression_language/how_to/inspect/
 - In Python, better async support for many core abstractions (thank you @cbornet!!)
 - Include response metadata in 
AIMessageto make it easy to access raw output from the underlying models - Tooling to visualize your runnables or your langgraph app
 - Interoperability of chat message histories across most providers
 - Over 20+ partner packages in python for popular integrations
 
What’s coming to LangChain?​
- We’ve been working hard on langgraph. We will be building more capabilities on top of it and focusing on making it the go-to framework for agent architectures.
 - Vectorstores V2! We’ll be revisiting our vectorstores abstractions to help improve usability and reliability.
 - Better documentation and versioned docs!
 - We’re planning a breaking release (0.3.0) sometime between July-September to upgrade to full support of Pydantic 2, and will drop support for Pydantic 1 (including objects originating from the 
v1namespace of Pydantic 2). 
What changed?​
Due to the rapidly evolving field, LangChain has also evolved rapidly.
This document serves to outline at a high level what has changed and why.