{"id":33,"library":"langchain","title":"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","language":"python","source_language":"en","source_url":"https://docs.langchain.com/oss/python/release-policy","tags":["langchain","llm","agents","orchestration","python","nodejs"],"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":[{"reason":"Required for OpenAI model access. Not included in base langchain package.","package":"langchain-openai","optional":false},{"reason":"Required for Anthropic/Claude model access. Not included in base langchain package.","package":"langchain-anthropic","optional":false},{"reason":"Required for stateful multi-agent workflows. Foundational runtime in v1.0.","package":"langgraph","optional":true}],"imports":[{"note":"Moved to partner package in 0.2. Wrong import raises ImportError in 1.0.","wrong":"from langchain import ChatOpenAI","symbol":"ChatOpenAI","correct":"from langchain_openai import ChatOpenAI"},{"note":"Moved to partner package in 0.2. Wrong import raises ImportError in 1.0.","wrong":"from langchain import ChatAnthropic","symbol":"ChatAnthropic","correct":"from langchain_anthropic import ChatAnthropic"},{"note":"create_react_agent still works in 1.0 but create_agent is now the idiomatic entry point.","wrong":"from langgraph.prebuilt import create_react_agent","symbol":"create_agent","correct":"from langchain import create_agent"}],"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":[{"fix":"Replace AgentExecutor with create_agent from langchain","message":"AgentExecutor is removed in v1.0. Use create_agent instead.","severity":"breaking","affected_versions":"< 1.0.0"},{"fix":"Use create_agent or direct llm.invoke() calls","message":"LCEL pipe syntax (prompt | llm | parser) is deprecated. Use explicit chaining.","severity":"breaking","affected_versions":"< 1.0.0"},{"fix":"Pin langchain-community version explicitly in requirements.txt","message":"langchain-community does not follow semver. Breaking changes can occur in minor releases.","severity":"breaking","affected_versions":"all"},{"fix":"Always install langchain-openai or langchain-anthropic alongside langchain","message":"pip install langchain alone is insufficient. Provider packages must be installed separately.","severity":"gotcha","affected_versions":"all"},{"fix":"astream_events(version='v2')","message":"astream_events(version='v1') uses vulnerable serialization. Use v2.","severity":"deprecated","affected_versions":"< 1.0.0"},{"fix":"Set the OPENAI_API_KEY environment variable or pass `openai_api_key='your_api_key'` to `ChatOpenAI`.","message":"OpenAI API key is missing. Set OPENAI_API_KEY environment variable or pass `api_key` directly to the client.","severity":"gotcha","affected_versions":"all"}],"env_vars":null,"last_verified":"2026-05-12T05:13:29.788Z","next_check":"2026-03-28T00:00:00.000Z","problems":[{"fix":"Ensure you're using the correct Python environment and install LangChain with 'pip install langchain'.","cause":"The 'langchain' module is not installed or is installed in a different Python environment.","error":"ModuleNotFoundError: No module named 'langchain'"},{"fix":"Install the module using 'pip install langchain-community'.","cause":"The 'langchain_community' module is not installed.","error":"ModuleNotFoundError: No module named 'langchain_community'"},{"fix":"Install the module using 'pip install langchain-openai'.","cause":"The 'langchain_openai' module is not installed.","error":"ModuleNotFoundError: No module named 'langchain_openai'"},{"fix":"Update your code to use the current modules and functions provided by LangChain for question answering tasks.","cause":"The 'question_answering' module has been deprecated or removed in recent versions of LangChain.","error":"ModuleNotFoundError: No module named 'langchain.chains.question_answering'"},{"fix":"Verify the correct module name and ensure it is available in your installed version of LangChain.","cause":"The 'neo4j_vector' module is not available in the 'langchain.vectorstores' package.","error":"ModuleNotFoundError: No module named 'langchain.vectorstores.neo4j_vector'"}],"ecosystem":"pypi","meta_description":null,"install_score":95,"install_tag":"verified","quickstart_score":80,"quickstart_tag":"verified","pypi_latest":null,"install_checks":{"last_tested":"2026-05-12","tag":"verified","tag_description":"installs cleanly on critical runtimes, fast import, recently tested","results":[{"runtime":"python:3.10-alpine","python_version":"3.10","os_libc":"alpine (musl)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":3.81,"mem_mb":39.7,"disk_size":"103.4M"},{"runtime":"python:3.10-slim","python_version":"3.10","os_libc":"slim (glibc)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":2.86,"mem_mb":39.7,"disk_size":"105M"},{"runtime":"python:3.11-alpine","python_version":"3.11","os_libc":"alpine (musl)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":4.85,"mem_mb":42.4,"disk_size":"104.7M"},{"runtime":"python:3.11-slim","python_version":"3.11","os_libc":"slim (glibc)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":4.11,"mem_mb":42.4,"disk_size":"113M"},{"runtime":"python:3.12-alpine","python_version":"3.12","os_libc":"alpine (musl)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":4.3,"mem_mb":41.7,"disk_size":"102.0M"},{"runtime":"python:3.12-slim","python_version":"3.12","os_libc":"slim (glibc)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":4.41,"mem_mb":41.7,"disk_size":"103M"},{"runtime":"python:3.13-alpine","python_version":"3.13","os_libc":"alpine (musl)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":4.2,"mem_mb":42.3,"disk_size":"101.7M"},{"runtime":"python:3.13-slim","python_version":"3.13","os_libc":"slim (glibc)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":4.18,"mem_mb":42.3,"disk_size":"103M"},{"runtime":"python:3.9-alpine","python_version":"3.9","os_libc":"alpine (musl)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":3.63,"mem_mb":40.4,"disk_size":"127.1M"},{"runtime":"python:3.9-slim","python_version":"3.9","os_libc":"slim (glibc)","variant":"default","exit_code":0,"wheel_type":null,"failure_reason":null,"install_time_s":null,"import_time_s":3.29,"mem_mb":40.4,"disk_size":"134M"}]},"quickstart_checks":{"last_tested":"2026-05-12","tag":"verified","tag_description":"quickstart runs on critical runtimes, recently tested","results":[{"runtime":"python:3.10-alpine","exit_code":0},{"runtime":"python:3.10-slim","exit_code":0},{"runtime":"python:3.11-alpine","exit_code":0},{"runtime":"python:3.11-slim","exit_code":0},{"runtime":"python:3.12-alpine","exit_code":0},{"runtime":"python:3.12-slim","exit_code":0},{"runtime":"python:3.13-alpine","exit_code":0},{"runtime":"python:3.13-slim","exit_code":0},{"runtime":"python:3.9-alpine","exit_code":0},{"runtime":"python:3.9-slim","exit_code":0}]}}