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Deprecations and Breaking Changes

This code contains a list of deprecations and removals in the langchain and langchain-core packages.

New features and improvements are not listed here. See the overview for a summary of what's new in this release.

Breaking changes​

As of release 0.2.0, langchain is required to be integration-agnostic. This means that code in langchain should not by default instantiate any specific chat models, llms, embedding models, vectorstores etc; instead, the user will be required to specify those explicitly.

The following functions and classes require an explicit LLM to be passed as an argument:

  • langchain.agents.agent_toolkits.vectorstore.toolkit.VectorStoreToolkit
  • langchain.agents.agent_toolkits.vectorstore.toolkit.VectorStoreRouterToolkit
  • langchain.chains.openai_functions.get_openapi_chain
  • langchain.chains.router.MultiRetrievalQAChain.from_retrievers
  • langchain.indexes.VectorStoreIndexWrapper.query
  • langchain.indexes.VectorStoreIndexWrapper.query_with_sources
  • langchain.indexes.VectorStoreIndexWrapper.aquery_with_sources
  • langchain.chains.flare.FlareChain

The following classes now require passing an explicit Embedding model as an argument:

  • langchain.indexes.VectostoreIndexCreator

The following code has been removed:

  • langchain.natbot.NatBotChain.from_default removed in favor of the from_llm class method.

Behavior was changed for the following code:

@tool decorator​

@tool decorator now assigns the function doc-string as the tool description. Previously, the @tool decorator using to prepend the function signature.

Before 0.2.0:

@tool
def my_tool(x: str) -> str:
"""Some description."""
return "something"

print(my_tool.description)

Would result in: my_tool: (x: str) -> str - Some description.

As of 0.2.0:

It will result in: Some description.

Code that moved to another package​

Code that was moved from langchain into another package (e.g, langchain-community)

If you try to import it from langchain, the import will keep on working, but will raise a deprecation warning. The warning will provide a replacement import statement.

python -c "from langchain.document_loaders.markdown import UnstructuredMarkdownLoader"
LangChainDeprecationWarning: Importing UnstructuredMarkdownLoader from langchain.document_loaders is deprecated. Please replace deprecated imports:

>> from langchain.document_loaders import UnstructuredMarkdownLoader

with new imports of:

>> from langchain_community.document_loaders import UnstructuredMarkdownLoader

We will continue supporting the imports in langchain until release 0.4 as long as the relevant package where the code lives is installed. (e.g., as long as langchain_community is installed.)

However, we advise for users to not rely on these imports and instead migrate to the new imports. To help with this process, we’re releasing a migration script via the LangChain CLI. See further instructions in migration guide.

Code targeted for removal​

Code that has better alternatives available and will eventually be removed, so there’s only a single way to do things. (e.g., predict_messages method in ChatModels has been deprecated in favor of invoke).

astream events V1​

If you are using astream_events, please review how to migrate to astream events v2.

langchain_core​

try_load_from_hub​

In module: utils.loading Deprecated: 0.1.30 Removal: 0.3.0

Alternative: Using the hwchase17/langchain-hub repo for prompts is deprecated. Please use https://smith.langchain.com/hub instead.

BaseLanguageModel.predict​

In module: language_models.base Deprecated: 0.1.7 Removal: 0.3.0

Alternative: invoke

BaseLanguageModel.predict_messages​

In module: language_models.base Deprecated: 0.1.7 Removal: 0.3.0

Alternative: invoke

BaseLanguageModel.apredict​

In module: language_models.base Deprecated: 0.1.7 Removal: 0.3.0

Alternative: ainvoke

BaseLanguageModel.apredict_messages​

In module: language_models.base Deprecated: 0.1.7 Removal: 0.3.0

Alternative: ainvoke

RunTypeEnum​

In module: tracers.schemas Deprecated: 0.1.0 Removal: 0.3.0

Alternative: Use string instead.

TracerSessionV1Base​

In module: tracers.schemas Deprecated: 0.1.0 Removal: 0.3.0

Alternative:

TracerSessionV1Create​

In module: tracers.schemas Deprecated: 0.1.0 Removal: 0.3.0

Alternative:

TracerSessionV1​

In module: tracers.schemas Deprecated: 0.1.0 Removal: 0.3.0

Alternative:

TracerSessionBase​

In module: tracers.schemas Deprecated: 0.1.0 Removal: 0.3.0

Alternative:

TracerSession​

In module: tracers.schemas Deprecated: 0.1.0 Removal: 0.3.0

Alternative:

BaseRun​

In module: tracers.schemas Deprecated: 0.1.0 Removal: 0.3.0

Alternative: Run

LLMRun​

In module: tracers.schemas Deprecated: 0.1.0 Removal: 0.3.0

Alternative: Run

ChainRun​

In module: tracers.schemas Deprecated: 0.1.0 Removal: 0.3.0

Alternative: Run

ToolRun​

In module: tracers.schemas Deprecated: 0.1.0 Removal: 0.3.0

Alternative: Run

BaseChatModel.call​

In module: language_models.chat_models Deprecated: 0.1.7 Removal: 0.3.0

Alternative: invoke

BaseChatModel.call_as_llm​

In module: language_models.chat_models Deprecated: 0.1.7 Removal: 0.3.0

Alternative: invoke

BaseChatModel.predict​

In module: language_models.chat_models Deprecated: 0.1.7 Removal: 0.3.0

Alternative: invoke

BaseChatModel.predict_messages​

In module: language_models.chat_models Deprecated: 0.1.7 Removal: 0.3.0

Alternative: invoke

BaseChatModel.apredict​

In module: language_models.chat_models Deprecated: 0.1.7 Removal: 0.3.0

Alternative: ainvoke

BaseChatModel.apredict_messages​

In module: language_models.chat_models Deprecated: 0.1.7 Removal: 0.3.0

Alternative: ainvoke

BaseLLM.call​

In module: language_models.llms Deprecated: 0.1.7 Removal: 0.3.0

Alternative: invoke

BaseLLM.predict​

In module: language_models.llms Deprecated: 0.1.7 Removal: 0.3.0

Alternative: invoke

BaseLLM.predict_messages​

In module: language_models.llms Deprecated: 0.1.7 Removal: 0.3.0

Alternative: invoke

BaseLLM.apredict​

In module: language_models.llms Deprecated: 0.1.7 Removal: 0.3.0

Alternative: ainvoke

BaseLLM.apredict_messages​

In module: language_models.llms Deprecated: 0.1.7 Removal: 0.3.0

Alternative: ainvoke

BaseRetriever.get_relevant_documents​

In module: retrievers Deprecated: 0.1.46 Removal: 0.3.0

Alternative: invoke

BaseRetriever.aget_relevant_documents​

In module: retrievers Deprecated: 0.1.46 Removal: 0.3.0

Alternative: ainvoke

ChatPromptTemplate.from_role_strings​

In module: prompts.chat Deprecated: 0.0.1 Removal:

Alternative: from_messages classmethod

ChatPromptTemplate.from_strings​

In module: prompts.chat Deprecated: 0.0.1 Removal:

Alternative: from_messages classmethod

BaseTool.call​

In module: tools Deprecated: 0.1.47 Removal: 0.3.0

Alternative: invoke

convert_pydantic_to_openai_function​

In module: utils.function_calling Deprecated: 0.1.16 Removal: 0.3.0

Alternative: langchain_core.utils.function_calling.convert_to_openai_function()

convert_pydantic_to_openai_tool​

In module: utils.function_calling Deprecated: 0.1.16 Removal: 0.3.0

Alternative: langchain_core.utils.function_calling.convert_to_openai_tool()

convert_python_function_to_openai_function​

In module: utils.function_calling Deprecated: 0.1.16 Removal: 0.3.0

Alternative: langchain_core.utils.function_calling.convert_to_openai_function()

format_tool_to_openai_function​

In module: utils.function_calling Deprecated: 0.1.16 Removal: 0.3.0

Alternative: langchain_core.utils.function_calling.convert_to_openai_function()

format_tool_to_openai_tool​

In module: utils.function_calling Deprecated: 0.1.16 Removal: 0.3.0

Alternative: langchain_core.utils.function_calling.convert_to_openai_tool()

langchain​

AgentType​

In module: agents.agent_types Deprecated: 0.1.0 Removal: 0.3.0

Alternative: Use LangGraph or new agent constructor methods like create_react_agent, create_json_agent, create_structured_chat_agent, etc.

Chain.call​

In module: chains.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative: invoke

Chain.acall​

In module: chains.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative: ainvoke

Chain.run​

In module: chains.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative: invoke

Chain.arun​

In module: chains.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative: ainvoke

Chain.apply​

In module: chains.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative: batch

LLMChain​

In module: chains.llm Deprecated: 0.1.17 Removal: 0.3.0

Alternative: RunnableSequence, e.g., prompt | llm

This migration guide has a side-by-side comparison.

LLMSingleActionAgent​

In module: agents.agent Deprecated: 0.1.0 Removal: 0.3.0

Alternative: Use LangGraph or new agent constructor methods like create_react_agent, create_json_agent, create_structured_chat_agent, etc.

Agent​

In module: agents.agent Deprecated: 0.1.0 Removal: 0.3.0

Alternative: Use LangGraph or new agent constructor methods like create_react_agent, create_json_agent, create_structured_chat_agent, etc.

OpenAIFunctionsAgent​

In module: agents.openai_functions_agent.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative: create_openai_functions_agent

ZeroShotAgent​

In module: agents.mrkl.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative: create_react_agent

MRKLChain​

In module: agents.mrkl.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative:

ConversationalAgent​

In module: agents.conversational.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative: create_react_agent

ConversationalChatAgent​

In module: agents.conversational_chat.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative: create_json_chat_agent

ChatAgent​

In module: agents.chat.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative: create_react_agent

OpenAIMultiFunctionsAgent​

In module: agents.openai_functions_multi_agent.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative: create_openai_tools_agent

ReActDocstoreAgent​

In module: agents.react.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative:

DocstoreExplorer​

In module: agents.react.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative:

ReActTextWorldAgent​

In module: agents.react.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative:

ReActChain​

In module: agents.react.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative:

SelfAskWithSearchAgent​

In module: agents.self_ask_with_search.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative: create_self_ask_with_search

SelfAskWithSearchChain​

In module: agents.self_ask_with_search.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative:

StructuredChatAgent​

In module: agents.structured_chat.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative: create_structured_chat_agent

RetrievalQA​

In module: chains.retrieval_qa.base Deprecated: 0.1.17 Removal: 0.3.0

Alternative: create_retrieval_chain This migration guide has a side-by-side comparison.

load_agent_from_config​

In module: agents.loading Deprecated: 0.1.0 Removal: 0.3.0

Alternative:

load_agent​

In module: agents.loading Deprecated: 0.1.0 Removal: 0.3.0

Alternative:

initialize_agent​

In module: agents.initialize Deprecated: 0.1.0 Removal: 0.3.0

Alternative: Use LangGraph or new agent constructor methods like create_react_agent, create_json_agent, create_structured_chat_agent, etc.

XMLAgent​

In module: agents.xml.base Deprecated: 0.1.0 Removal: 0.3.0

Alternative: create_xml_agent

CohereRerank​

In module: retrievers.document_compressors.cohere_rerank Deprecated: 0.0.30 Removal: 0.3.0

Alternative: langchain_cohere.CohereRerank

ConversationalRetrievalChain​

In module: chains.conversational_retrieval.base Deprecated: 0.1.17 Removal: 0.3.0

Alternative: create_history_aware_retriever together with create_retrieval_chain (see example in docstring) This migration guide has a side-by-side comparison.

create_extraction_chain_pydantic​

In module: chains.openai_tools.extraction Deprecated: 0.1.14 Removal: 0.3.0

Alternative: with_structured_output method on chat models that support tool calling.

create_openai_fn_runnable​

In module: chains.structured_output.base Deprecated: 0.1.14 Removal: 0.3.0

Alternative: with_structured_output method on chat models that support tool calling.

create_structured_output_runnable​

In module: chains.structured_output.base Deprecated: 0.1.17 Removal: 0.3.0

Alternative: with_structured_output method on chat models that support tool calling.

create_openai_fn_chain​

In module: chains.openai_functions.base Deprecated: 0.1.1 Removal: 0.3.0

Alternative: create_openai_fn_runnable

create_structured_output_chain​

In module: chains.openai_functions.base Deprecated: 0.1.1 Removal: 0.3.0

Alternative: ChatOpenAI.with_structured_output

create_extraction_chain​

In module: chains.openai_functions.extraction Deprecated: 0.1.14 Removal: 0.3.0

Alternative: with_structured_output method on chat models that support tool calling.

create_extraction_chain_pydantic​

In module: chains.openai_functions.extraction Deprecated: 0.1.14 Removal: 0.3.0

Alternative: with_structured_output method on chat models that support tool calling.


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