LangChain 1.0 released
LangChain reached 1.0. The release notes list the final changes before it: new middleware (shell, file search, tool retry), an injectable ToolRuntime, state-schema options for create_agent, and Python 3.14 support.
What happened
langchain==1.0.0 was released on GitHub, the same day as LangGraph 1.0.
The technical details
The release notes are a list of changes since 0.3.27. The notable ones:
- middleware:
ShellToolMiddlewareandClaudeBashToolMiddleware, file-search middleware, tool retry middleware, and model/tool call limits - an injectable
ToolRuntime, so tools can access runtime context and state state_schemasupport increate_agent- Python 3.14 support
Why it matters
When I studied LangChain in April–May 2026, I used version 1.4. The 1.0 API is the base of what I learned: create_agent plus middleware around tool calls, with LangGraph underneath. These notes only list changes, so the design explanation is in LangChain’s agent docs, linked above.
Sources
- langchain==1.0.0 release notes — GitHub · langchain-ai/langchain
- LangChain docs: Agents — LangChain
This is a summary written from the linked public sources. Figures and numbers are as reported there.