{"id":"langchain","title":"LangChain","library":"langchain","description":"LangChain is an orchestration framework for building LLM-powered applications and agents. It provides abstractions for chaining model calls, tool use, memory, and multi-agent coordination. As of v1.0, LangGraph is the foundational runtime for stateful agent execution.","status":"active","version":"1.0.x","install":[{"cmd":"pip install langchain langchain-openai langchain-anthropic","lang":"bash","label":"Python"},{"cmd":"npm install langchain @langchain/openai @langchain/anthropic","lang":"bash","label":"Node.js"}],"dependencies":[{"package":"langchain-openai","reason":"Required for OpenAI model access. Not included in base langchain package.","optional":false},{"package":"langchain-anthropic","reason":"Required for Anthropic/Claude model access. Not included in base langchain package.","optional":false},{"package":"langgraph","reason":"Required for stateful multi-agent workflows. Foundational runtime in v1.0.","optional":true}],"imports":[{"symbol":"ChatOpenAI","correct":"from langchain_openai import ChatOpenAI","wrong":"from langchain import ChatOpenAI","note":"Moved to partner package in 0.2. Wrong import raises ImportError in 1.0."},{"symbol":"ChatAnthropic","correct":"from langchain_anthropic import ChatAnthropic","wrong":"from langchain import ChatAnthropic","note":"Moved to partner package in 0.2. Wrong import raises ImportError in 1.0."},{"symbol":"create_agent","correct":"from langchain import create_agent","wrong":"from langgraph.prebuilt import create_react_agent","note":"create_react_agent still works in 1.0 but create_agent is now the idiomatic entry point."}],"quickstart":{"code":"from langchain_openai import ChatOpenAI\n\nllm = ChatOpenAI(model='gpt-4o', temperature=0)\nresponse = llm.invoke('What is the capital of France?')\nprint(response.content)","lang":"python","description":"Minimal LLM call using ChatOpenAI in LangChain 1.0."},"warnings":[{"severity":"breaking","message":"AgentExecutor is removed in v1.0. Use create_agent instead.","affected_versions":"< 1.0.0","fix":"Replace AgentExecutor with create_agent from langchain"},{"severity":"breaking","message":"LCEL pipe syntax (prompt | llm | parser) is deprecated. Use explicit chaining.","affected_versions":"< 1.0.0","fix":"Use create_agent or direct llm.invoke() calls"},{"severity":"breaking","message":"langchain-community does not follow semver. Breaking changes can occur in minor releases.","affected_versions":"all","fix":"Pin langchain-community version explicitly in requirements.txt"},{"severity":"gotcha","message":"pip install langchain alone is insufficient. Provider packages must be installed separately.","affected_versions":"all","fix":"Always install langchain-openai or langchain-anthropic alongside langchain"},{"severity":"deprecated","message":"astream_events(version='v1') uses vulnerable serialization. Use v2.","affected_versions":"< 1.0.0","fix":"astream_events(version='v2')"}],"last_verified":"2026-02-28","next_check":"2026-03-28","source_url":"https://docs.langchain.com/oss/python/release-policy","language":"en","source_language":"en","tags":["langchain","llm","agents","orchestration","python","nodejs"]}