docs: Add langchain over time (#21434)

Co-authored-by: Erick Friis <erick@langchain.dev>

docs/Makefile

@@ -13,7 +13,7 @@ OUTPUT_NEW_DOCS_DIR = $(OUTPUT_NEW_DIR)/docs
 
 PYTHON = .venv/bin/python
 
-PARTNER_DEPS_LIST := $(shell ls -1 ../libs/partners | grep -vE "airbyte|ibm" | xargs -I {} echo "../libs/partners/{}" | tr '\n' ' ')
+PARTNER_DEPS_LIST := $(shell find ../libs/partners -mindepth 1 -maxdepth 1 -type d -exec test -e "{}/pyproject.toml" \; -print | grep -vE "airbyte|ibm" | tr '\n' ' ')
 
 PORT ?= 3001
 

docs/docs/changelog/langchain.mdx

@@ -1,36 +0,0 @@
-# langchain
-
-## 0.1.0 (Jan 5, 2024)
-
-#### Deleted
-
-No deletions.
-
-#### Deprecated
-
-Deprecated classes and methods will be removed in 0.2.0
-
-| Deprecated                | Alternative                       | Reason                                         |
-|---------------------------------|-----------------------------------|------------------------------------------------|
-| ChatVectorDBChain               | ConversationalRetrievalChain      | More general to all retrievers                 |
-| create_ernie_fn_chain           | create_ernie_fn_runnable          | Use LCEL under the hood                        |
-| created_structured_output_chain | create_structured_output_runnable | Use LCEL under the hood                        |
-| NatBotChain                     |                                   | Not used                                       |
-| create_openai_fn_chain          | create_openai_fn_runnable         | Use LCEL under the hood                        |
-| create_structured_output_chain  | create_structured_output_runnable | Use LCEL under the hood                        |
-| load_query_constructor_chain    | load_query_constructor_runnable   | Use LCEL under the hood                        |
-| VectorDBQA                      | RetrievalQA                       | More general to all retrievers                 |
-| Sequential Chain                | LCEL                              | Obviated by LCEL                               |
-| SimpleSequentialChain           | LCEL                              | Obviated by LCEL                               |
-| TransformChain                  | LCEL/RunnableLambda               | Obviated by LCEL                               |
-| create_tagging_chain            | create_structured_output_runnable | Use LCEL under the hood                        |
-| ChatAgent                       | create_react_agent                | Use LCEL builder over a class                  |
-| ConversationalAgent             | create_react_agent                | Use LCEL builder over a class                  |
-| ConversationalChatAgent         | create_json_chat_agent            | Use LCEL builder over a class                  |
-| initialize_agent                | Individual create agent methods   | Individual create agent methods are more clear |
-| ZeroShotAgent                   | create_react_agent                | Use LCEL builder over a class                  |
-| OpenAIFunctionsAgent            | create_openai_functions_agent     | Use LCEL builder over a class                  |
-| OpenAIMultiFunctionsAgent       | create_openai_tools_agent         | Use LCEL builder over a class                  |
-| SelfAskWithSearchAgent          | create_self_ask_with_search       | Use LCEL builder over a class                  |
-| StructuredChatAgent             | create_structured_chat_agent      | Use LCEL builder over a class                  |
-| XMLAgent                        | create_xml_agent                  | Use LCEL builder over a class                  |

docs/docs/changes/changelog/core.mdx

@@ -1,27 +1,10 @@
 # langchain-core
 
-## 0.1.7 (Jan 5, 2024)
-
-#### Deleted
-
-No deletions.
+## 0.1.x
 
 #### Deprecated
 
 - `BaseChatModel` methods `__call__`, `call_as_llm`, `predict`, `predict_messages`. Will be removed in 0.2.0. Use `BaseChatModel.invoke` instead.
 - `BaseChatModel` methods `apredict`, `apredict_messages`. Will be removed in 0.2.0. Use `BaseChatModel.ainvoke` instead.
 - `BaseLLM` methods `__call__, `predict`, `predict_messages`. Will be removed in 0.2.0. Use `BaseLLM.invoke` instead.
-- `BaseLLM` methods `apredict`, `apredict_messages`. Will be removed in 0.2.0. Use `BaseLLM.ainvoke` instead.
-
-#### Fixed
-
-- Restrict recursive URL scraping: [#15559](https://github.com/langchain-ai/langchain/pull/15559)
-
-#### Added
-
-No additions.
-
-#### Beta
-
-- Marked `langchain_core.load.load` and `langchain_core.load.loads` as beta.
-- Marked `langchain_core.beta.runnables.context.ContextGet` and `langchain_core.beta.runnables.context.ContextSet` as beta.
+- `BaseLLM` methods `apredict`, `apredict_messages`. Will be removed in 0.2.0. Use `BaseLLM.ainvoke` instead.

docs/docs/changes/changelog/langchain.mdx

@@ -0,0 +1,93 @@
+# langchain
+
+## 0.2.0
+
+### Deleted
+
+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.
+
+### Deprecated
+
+We have two main types of deprecations:
+
+1. 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
+python -c "from langchain.document_loaders.markdown import UnstructuredMarkdownLoader"
+
+```
+
+```python
+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.
+
+1. 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`).
+
+Many of these were marked for removal in 0.2. We have bumped the removal to 0.3.
+
+
+## 0.1.0 (Jan 5, 2024)
+
+### Deleted
+
+No deletions.
+
+### Deprecated
+
+Deprecated classes and methods will be removed in 0.2.0
+
+| Deprecated                      | Alternative                       | Reason                                         |
+|---------------------------------|-----------------------------------|------------------------------------------------|
+| ChatVectorDBChain               | ConversationalRetrievalChain      | More general to all retrievers                 |
+| create_ernie_fn_chain           | create_ernie_fn_runnable          | Use LCEL under the hood                        |
+| created_structured_output_chain | create_structured_output_runnable | Use LCEL under the hood                        |
+| NatBotChain                     |                                   | Not used                                       |
+| create_openai_fn_chain          | create_openai_fn_runnable         | Use LCEL under the hood                        |
+| create_structured_output_chain  | create_structured_output_runnable | Use LCEL under the hood                        |
+| load_query_constructor_chain    | load_query_constructor_runnable   | Use LCEL under the hood                        |
+| VectorDBQA                      | RetrievalQA                       | More general to all retrievers                 |
+| Sequential Chain                | LCEL                              | Obviated by LCEL                               |
+| SimpleSequentialChain           | LCEL                              | Obviated by LCEL                               |
+| TransformChain                  | LCEL/RunnableLambda               | Obviated by LCEL                               |
+| create_tagging_chain            | create_structured_output_runnable | Use LCEL under the hood                        |
+| ChatAgent                       | create_react_agent                | Use LCEL builder over a class                  |
+| ConversationalAgent             | create_react_agent                | Use LCEL builder over a class                  |
+| ConversationalChatAgent         | create_json_chat_agent            | Use LCEL builder over a class                  |
+| initialize_agent                | Individual create agent methods   | Individual create agent methods are more clear |
+| ZeroShotAgent                   | create_react_agent                | Use LCEL builder over a class                  |
+| OpenAIFunctionsAgent            | create_openai_functions_agent     | Use LCEL builder over a class                  |
+| OpenAIMultiFunctionsAgent       | create_openai_tools_agent         | Use LCEL builder over a class                  |
+| SelfAskWithSearchAgent          | create_self_ask_with_search       | Use LCEL builder over a class                  |
+| StructuredChatAgent             | create_structured_chat_agent      | Use LCEL builder over a class                  |
+| XMLAgent                        | create_xml_agent                  | Use LCEL builder over a class                  |

docs/docs/langchain_over_time.mdx

@@ -1,45 +0,0 @@
-# LangChain Over Time
-
-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.
-
-## 0.2
-
-
-## 0.1
-
-The 0.1 release marked a few key changes for LangChain.
-By this point, the LangChain ecosystem had become large both in the breadth of what it enabled as well as the community behind it.
-
-
-**Split of packages**
-
-LangChain was split up into several packages to increase modularity and decrease bloat.
-First, `langchain-core` is created as a lightweight core library containing the base abstractions,
-some core implementations of those abstractions, and the generic runtime for creating chains.
-Next, all third party integrations are split into `langchain-community` or their own individual partner packages.
-Higher level chains and agents remain in `langchain`.
-
-**`Runnables`**
-
-Having a specific class for each chain was proving not very scalable or flexible.
-Although these classes were left alone (without deprecation warnings) for this release,
-in the documentation much more space was given to generic runnables.
-
-## < 0.1
-
-There are several key characteristics of LangChain pre-0.1.
-
-**Singular Package**
-
-LangChain was largely a singular package.
-The only exception was was `langchain-experimental`, which largely held more experimental code.
-This meant that ALL integrations lived inside `langchain`.
-
-
-**Chains as classes**
-
-Most high level chains were largely their own classes.
-There was a base `Chain` class from which all chains inherited.
-This meant that in order to chain the logic inside a chain you basically had to modify the source code.
-There were a few chains that were meant to be more generic (`SequentialChain`, `RouterChain`)

docs/docs/langsmith/index.ipynb

@@ -7,6 +7,25 @@
     "tags": []
    },
    "source": [
+    "# 🦜🛠️ LangSmith\n",
+    "\n",
+    "[LangSmith](https://smith.langchain.com) helps you trace and evaluate your language model applications and intelligent agents to help you\n",
+    "move from prototype to production.\n",
+    "\n",
+    "Check out the [interactive walkthrough](/docs/langsmith/walkthrough) to get started.\n",
+    "\n",
+    "For more information, please refer to the [LangSmith documentation](https://docs.smith.langchain.com/).\n",
+    "\n",
+    "For tutorials and other end-to-end examples demonstrating ways to integrate LangSmith in your workflow,\n",
+    "check out the [LangSmith Cookbook](https://github.com/langchain-ai/langsmith-cookbook). Some of the guides therein include:\n",
+    "\n",
+    "- Leveraging user feedback in your JS application ([link](https://github.com/langchain-ai/langsmith-cookbook/blob/main/feedback-examples/nextjs/README.md)).\n",
+    "- Building an automated feedback pipeline ([link](https://github.com/langchain-ai/langsmith-cookbook/blob/main/feedback-examples/algorithmic-feedback/algorithmic_feedback.ipynb)).\n",
+    "- How to evaluate and audit your RAG workflows ([link](https://github.com/langchain-ai/langsmith-cookbook/tree/main/testing-examples/qa-correctness)).\n",
+    "- How to fine-tune an LLM on real usage data ([link](https://github.com/langchain-ai/langsmith-cookbook/blob/main/fine-tuning-examples/export-to-openai/fine-tuning-on-chat-runs.ipynb)).\n",
+    "- How to use the [LangChain Hub](https://smith.langchain.com/hub) to version your prompts ([link](https://github.com/langchain-ai/langsmith-cookbook/blob/main/hub-examples/retrieval-qa-chain/retrieval-qa.ipynb))\n",
+    "\n",
+    "\n",
     "# LangSmith Walkthrough\n",
     "[![Open In Colab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/langchain-ai/langchain/blob/master/docs/docs/langsmith/walkthrough.ipynb)\n",
     "\n",

docs/docs/langsmith/index.md

@@ -1,22 +0,0 @@
----
-sidebar_class_name: hidden
----
-
-# 🦜🛠️ LangSmith
-
-[LangSmith](https://smith.langchain.com) helps you trace and evaluate your language model applications and intelligent agents to help you
-move from prototype to production.
-
-Check out the [interactive walkthrough](/docs/langsmith/walkthrough) to get started.
-
-For more information, please refer to the [LangSmith documentation](https://docs.smith.langchain.com/).
-
-For tutorials and other end-to-end examples demonstrating ways to integrate LangSmith in your workflow,
-check out the [LangSmith Cookbook](https://github.com/langchain-ai/langsmith-cookbook). Some of the guides therein include:
-
-- Leveraging user feedback in your JS application ([link](https://github.com/langchain-ai/langsmith-cookbook/blob/main/feedback-examples/nextjs/README.md)).
-- Building an automated feedback pipeline ([link](https://github.com/langchain-ai/langsmith-cookbook/blob/main/feedback-examples/algorithmic-feedback/algorithmic_feedback.ipynb)).
-- How to evaluate and audit your RAG workflows ([link](https://github.com/langchain-ai/langsmith-cookbook/tree/main/testing-examples/qa-correctness)).
-- How to fine-tune an LLM on real usage data ([link](https://github.com/langchain-ai/langsmith-cookbook/blob/main/fine-tuning-examples/export-to-openai/fine-tuning-on-chat-runs.ipynb)).
-- How to use the [LangChain Hub](https://smith.langchain.com/hub) to version your prompts ([link](https://github.com/langchain-ai/langsmith-cookbook/blob/main/hub-examples/retrieval-qa-chain/retrieval-qa.ipynb))
-

docs/docs/versions/overview.mdx

@@ -0,0 +1,102 @@
+---
+sidebar_position: 0
+sidebar_label: Overview
+---
+
+# LangChain Over Time
+
+## 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](https://python.langchain.com/docs/expression_language/streaming/#using-stream-events)
+- [Standardized tool calling support](https://blog.langchain.dev/tool-calling-with-langchain/)
+- A standardized interface for [structuring output](https://github.com/langchain-ai/langchain/discussions/18154)
+- [@chain decorator](https://python.langchain.com/docs/expression_language/how_to/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](https://github.com/cbornet)!!)
+- Include response metadata in `AIMessage` to make it easy to access raw output from the underlying models
+- Tooling to visualize [your runnables](https://python.langchain.com/docs/expression_language/how_to/inspect/) or [your langgraph app](https://github.com/langchain-ai/langgraph/blob/main/examples/visualization.ipynb)
+- Interoperability of chat message histories across most providers
+- [Over 20+ partner packages in python](https://python.langchain.com/docs/integrations/platforms/) for popular integrations
+
+## What’s coming to LangChain?
+
+- We’ve been working hard on [langgraph](https://python.langchain.com/docs/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](https://github.com/langchain-ai/langchain/discussions/19339), and will drop support for Pydantic 1 (including objects originating from the `v1` namespace 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.
+
+### TLDR
+
+**As of 0.2.0:**
+
+- This release completes the work that we started with release 0.1.0 by removing the dependency of `langchain` on `langchain-community`.
+- `langchain` package no longer requires `langchain-community` . Instead `langchain-community` will now depend on `langchain-core` and `langchain` .
+- User code that still relies on deprecated imports from `langchain` will continue to work as long `langchain_community` is installed. These imports will start raising errors in release 0.4.x.
+
+**As of 0.1.0:**
+
+- `langchain` was split into the following component packages: `langchain-core`, `langchain`, `langchain-community`, `langchain-[partner]` to improve the usability of langchain code in production settings. You can read more about it on our [blog](https://blog.langchain.dev/langchain-v0-1-0/).
+
+### Ecosystem Organization
+
+By the release of 0.1.0, LangChain had grown to a large ecosystem with many integrations and a large community.
+
+To improve the usability of LangChain in production, we split the single `langchain` package into multiple packages. This allowed us to create a good foundation architecture for the LangChain ecosystem and improve the usability of `langchain` in production.
+
+Here is the high level break down of the Eco-system:
+
+- **langchain-core**:  contains core abstractions involving LangChain Runnables, tooling for observability, and base implementations of important abstractions (e.g., Chat Models).
+- **langchain:** contains generic code that is built using interfaces defined in `langchain-core`. This package is for code that generalizes well across different implementations of specific interfaces. For example, `create_tool_calling_agent` works across chat models that support [tool calling capabilities](https://blog.langchain.dev/tool-calling-with-langchain/).
+- **langchain-community**: community maintained 3rd party integrations. Contains integrations based on interfaces defined in **langchain-core**. Maintained by the LangChain community.
+- **Partner Packages (e.g., langchain-[partner])**: Partner packages are packages dedicated to especially popular integrations (e.g., `langchain-openai`, `langchain-anthropic` etc.). The dedicated packages generally benefit from better reliability and support.
+- `langgraph`: Build robust and stateful multi-actor applications with LLMs by modeling steps as edges and nodes in a graph.
+- `langserve`: Deploy LangChain chains as REST APIs.
+
+
+In the 0.1.0 release, `langchain-community` was retained as required a dependency of `langchain`.
+
+This allowed imports of vectorstores, chat models, and other integrations to continue working through `langchain`
+rather than forcing users to update all of their imports to `langchain-community`.
+
+For the 0.2.0 release, we’re removing the dependency of `langchain` on `langchain-community`. This is something we’ve been planning to do since the 0.1 release because we believe this is the right package architecture.
+
+Old imports will continue to work as long as `langchain-community` is installed. These imports will be removed in the 0.4.0 release.
+
+To understand why we think breaking the dependency of `langchain` on `langchain-community` is best we should understand what each package is meant to do.
+
+`langchain` is meant to contain high-level chains and agent architectures. The logic in these should be specified at the level of abstractions like `ChatModel` and `Retriever`, and should not be specific to any one integration. This has two main benefits:
+
+1. `langchain` is fairly lightweight. Here is the full list of required dependencies (after the split)
+
+    ```toml
+    python = ">=3.8.1,<4.0"
+    langchain-core = "^0.2.0"
+    langchain-text-splitters = ">=0.0.1,<0.1"
+    langsmith = "^0.1.17"
+    pydantic = ">=1,<3"
+    SQLAlchemy = ">=1.4,<3"
+    requests = "^2"
+    PyYAML = ">=5.3"
+    numpy = "^1"
+    aiohttp = "^3.8.3"
+    tenacity = "^8.1.0"
+    jsonpatch = "^1.33"
+    ```
+
+2. `langchain` chains/agents are largely integration-agnostic, which makes it easy to experiment with different integrations and future-proofs your code should there be issues with one specific integration.
+
+There is also a third less tangible benefit which is that being integration-agnostic forces us to find only those very generic abstractions and architectures which generalize well across integrations. Given how general the abilities of the foundational tech are, and how quickly the space is moving, having generic architectures is a good way of future-proofing your applications.
+
+`langchain-community` is intended to have all integration-specific components that are not yet being maintained in separate `langchain-{partner}` packages. Today this is still the majority of integrations and a lot of code. This code is primarily contributed by the community, while `langchain` is largely written by core maintainers. All of these integrations use optional dependencies and conditional imports, which prevents dependency bloat and conflicts but means compatible dependency versions are not made explicit. Given the volume of integrations in `langchain-community` and the speed at which integrations change, it’s very hard to follow semver versioning, and we currently don’t.
+
+All of which is to say that there’s no large benefits to `langchain` depending on `langchain-community` and some obvious downsides: the functionality in `langchain` should be integration agnostic anyways, `langchain-community` can’t be properly versioned, and depending on `langchain-community` increases the [vulnerability surface](https://github.com/langchain-ai/langchain/discussions/19083) of `langchain`.
+
+For more context about the reason for the organization please see our blog: https://blog.langchain.dev/langchain-v0-1-0/

docs/docs/versions/packages.mdx

@@ -1,3 +1,8 @@
+---
+sidebar_position: 3
+sidebar_label: Packages
+---
+
 # 📕 Package Versioning
 
 As of now, LangChain has an ad hoc release process: releases are cut with high frequency by
@@ -23,7 +28,7 @@ Patch version increases will occur for:
 
 ## `langchain`
 
-`langchain` is currently on version `0.1.x`
+`langchain` is currently on version `0.2.x`
 
 Minor version increases will occur for:
 
@@ -34,16 +39,13 @@ Patch version increases will occur for:
 - Bug fixes
 - New features
 - Any changes to private interfaces
-- Any changes to `beta` features
-
-We are working on the `langchain` v0.2 release, which will have some breaking changes to legacy Chains and Agents.
-Additionally, we will remove `langchain-community` as a dependency and stop re-exporting integrations that have been moved to `langchain-community`.
+- Any changes to `beta` features.
 
 ## `langchain-community`
 
-`langchain-community` is currently on version `0.0.x`
+`langchain-community` is currently on version `0.2.x`
 
-All changes will be accompanied by a patch version increase.
+All changes will be accompanied by the same type of version increase as changes in `langchain`.
 
 ## `langchain-experimental`
 

docs/docs/versions/release_policy.mdx

@@ -0,0 +1,83 @@
+---
+sidebar_position: 2
+sidebar_label: Release Policy
+---
+
+# LangChain Releases
+
+The LangChain ecosystem is composed of different component packages (e.g., `langchain-core`, `langchain`, `langchain-community`, `langgraph`, `langserve`, partner packages etc.)
+
+## Versioning
+
+### `langchain` and `langchain-core`
+
+`langchain` and `langchain-core` follow [semantic versioning](https://semver.org/) in the format of 0.**Y**.**Z**. The packages are under rapid development, and so are currently versioning the packages with a major version of 0.
+
+Minor version increases will occur for:
+
+- Breaking changes for any public interfaces marked as `beta`.
+
+Patch version increases will occur for:
+
+- Bug fixes
+- New features
+- Any changes to private interfaces
+- Any changes to `beta` features
+
+When upgrading between minor versions, users should review the list of breaking changes and deprecations.
+
+From time to time, we will version packages as **release candidates**. These are versions that are intended to be released as stable versions, but we want to get feedback from the community before doing so. Release candidates will be versioned as 0.**Y**.**Z**rc**N**. For example, 0.2.0rc1. If no issues are found, the release candidate will be released as a stable version with the same version number. If issues are found, we will release a new release candidate with an incremented `N` value (e.g., 0.2.0rc2).
+
+### Other packages in the langchain ecosystem
+
+Other packages in the ecosystem (including user packages) can follow a different versioning scheme, but are generally expected to pin to specific minor versions of `langchain` and `langchain-core`.
+
+## Release Cadence
+
+We expect to space out **minor** releases (e.g., from 0.2.0 to 0.3.0) of `langchain` and `langchain-core` by at least 2-3 months, as such releases may contain breaking changes.
+
+Patch versions are released frequently as they contain bug fixes and new features.
+
+## API Stability
+
+The development of LLM applications is a rapidly evolving field, and we are constantly learning from our users and the community. As such, we expect that the APIs in `langchain` and `langchain-core` will continue to evolve to better serve the needs of our users.
+
+Even though both `langchain` and `langchain-core` are currently in a pre-1.0 state, we are committed to maintaining API stability in these packages.
+
+- Breaking changes to the public API will result in a minor version bump (the second digit)
+- Any bug fixes or new features will result in a patch version bump (the third digit)
+
+We will generally try to avoid making unnecessary changes, and will provide a deprecation policy for features that are being removed.
+
+### Stability of Other Packages
+
+The stability of other packages in the LangChain ecosystem may vary:
+
+- `langchain-community` is a community maintained package that contains 3rd party integrations. While we do our best to review and test changes in `langchain-community`, `langchain-community` is expected to experience more breaking changes than `langchain` and `langchain-core` as it contains many community contributions.
+- Partner packages may follow different stability and versioning policies, and users should refer to the documentation of those packages for more information; however, in general these packages are expected to be stable.
+
+### What is a "API Stability"?
+
+API stability means:
+
+- All the public APIs (everything in this documentation) will not be moved or renamed without providing backwards-compatible aliases.
+- If new features are added to these APIs – which is quite possible – they will not break or change the meaning of existing methods. In other words, "stable" does not (necessarily) mean "complete."
+- If, for some reason, an API declared stable must be removed or replaced, it will be declared deprecated but will remain in the API for at least two minor releases. Warnings will be issued when the deprecated method is called.
+
+### **APIs marked as internal**
+
+Certain APIs are explicitly marked as “internal” in a couple of ways:
+
+- Some documentation refers to internals and mentions them as such. If the documentation says that something is internal, it may change.
+- Functions, methods, and other objects prefixed by a leading underscore (**`_`**). This is the standard Python convention of indicating that something is private; if any method starts with a single **`_`**, it’s an internal API.
+    - **Exception:** Certain methods are prefixed with `_` , but do not contain an implementation. These methods are *meant* to be overridden by sub-classes that provide the implementation. Such methods are generally part of the **Public API** of LangChain.
+
+## Deprecation Policy
+
+We will generally avoid deprecating features until a better alternative is available.
+
+When a feature is deprecated, it will continue to work in the current and next minor version of `langchain` and `langchain-core`. After that, the feature will be removed.
+
+Since we're expecting to space out minor releases by at least 2-3 months, this means that a feature can be removed within 2-6 months of being deprecated.
+
+In some situations, we may allow the feature to remain in the code base for longer periods of time, if it's not causing issues in the packages, to reduce the burden on users.

docs/docs/versions/v0_2.mdx

@@ -0,0 +1,175 @@
+---
+sidebar_position: 1
+sidebar_label: v0.2
+---
+
+# LangChain v0.2
+
+LangChain v0.2 was released in May 2024. This release includes a number of breaking changes and deprecations. This document contains a guide on upgrading to 0.2.x, as well as a list of deprecations and breaking changes.
+
+## Migration
+
+This documentation will help you upgrade your code to LangChain `0.2.x.`. To prepare for migration, we first recommend you take the following steps:
+
+1. install the 0.2.x versions of langchain-core, langchain and upgrade to recent versions of other packages that you may be using (e.g. langgraph, langchain-community, langchain-openai, etc.)
+2. Verify that your code runs properly with the new packages (e.g., unit tests pass)
+3. Install a recent version of `langchain-cli` , and use the tool to replace old imports used by your code with the new imports. (See instructions below.)
+4. Manually resolve any remaining deprecation warnings
+5. Re-run unit tests
+
+### Upgrade to new imports
+
+We created a tool to help migrate your code. This tool is still in **beta** and may not cover all cases, but
+we hope that it will help you migrate your code more quickly.
+
+The migration script has the following limitations:
+
+1. It’s limited to helping users move from old imports to new imports. It doesn’t help address other deprecations.
+2. It can’t handle imports that involve `as` .
+3. New imports are always placed in global scope, even if the old import that was replaced was located inside some local scope (e..g, function body).
+4. It will likely miss some deprecated imports.
+
+Here is an example of the import changes that the migration script can help apply automatically:
+
+
+| From Package        | To Package               | Deprecated Import                                                  | New Import                                                          |
+|---------------------|--------------------------|--------------------------------------------------------------------|---------------------------------------------------------------------|
+| langchain           | langchain-community      | from langchain.vectorstores import InMemoryVectorStore             | from langchain_community.vectorstores import InMemoryVectorStore    |
+| langchain-community | langchain_openai         | from langchain_community.chat_models import ChatOpenAI             | from langchain_openai import ChatOpenAI                             |
+| langchain-community | langchain-core           | from langchain_community.document_loaders import Blob              | from langchain_core.document_loaders import Blob                    |
+| langchain           | langchain-core           | from langchain.schema.document import Document                     | from langchain_core.documents import Document                       |
+| langchain           | langchain-text-splitters | from langchain.text_splitter import RecursiveCharacterTextSplitter | from langchain_text_splitters import RecursiveCharacterTextSplitter |
+
+
+#### Deprecation Timeline
+
+We have two main types of deprecations:
+
+1. 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
+ python -c "from langchain.document_loaders.markdown import UnstructuredMarkdownLoader"
+
+    ```
+
+ ```python
+ 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.
+
+2. 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`).
+
+Many of these were marked for removal in 0.2. We have bumped the removal to 0.3.
+
+
+#### Installation
+
+```bash
+pip install langchain-cli
+langchain-cli --version # <-- Make sure the version is at least 0.0.22
+```
+
+#### Usage
+
+Given that the migration script is not perfect, you should make sure you have a backup of your code first (e.g., using version control like `git`).
+
+You will need to run the migration script **twice** as it only applies one import replacement per run.
+
+For example, say your code still uses `from langchain.chat_models import ChatOpenAI`:
+
+After the first run, you’ll get: `from langchain_community.chat_models import ChatOpenAI`
+After the second run, you’ll get: `from langchain_openai import ChatOpenAI`
+
+```bash
+# Run a first time
+# Will replace from langchain.chat_models import ChatOpenAI
+langchain-cli migrate [path to code] --diff # Preview
+langchain-cli migrate [path to code] # Apply
+
+# Run a second time to apply more import replacements
+langchain-cli migrate [path to code] --diff # Preview
+langchain-cli migrate [path to code] # Apply
+```
+
+#### Other Options
+
+```bash
+# See help menu
+langchain-cli migrate --help
+# Preview Changes without applying
+langchain-cli migrate --diff [path to code]
+# Run on code including ipython notebooks
+# Apply all import updates except for updates from langchain to langchain-core
+langchain-cli migrate --disable langchain_to_core --include-ipynb [path to code]
+```
+
+## Deprecations and Breaking Changes
+
+This code contains a list of deprecations and removals in the `langchain` and `langchain-core` packages.
+
+### Breaking Changes in 0.2.0
+
+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.
+
+
+### Deprecations
+
+We have two main types of deprecations:
+
+1. 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
+    python -c "from langchain.document_loaders.markdown import UnstructuredMarkdownLoader"
+    ```
+
+    ```python
+    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.
+
+2. 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`).
+
+    Many of these were marked for removal in 0.2. We have bumped the removal to 0.3.

docs/docusaurus.config.js

@@ -176,11 +176,6 @@ const config = {
                 docId: "people",
                 label: "People",
               },
-              {
-                type: "doc",
-                docId: "packages",
-                label: "Versioning",
-              },
               {
                 type: "doc",
                 docId: "contributing/index",

docs/sidebars.js

@@ -58,24 +58,26 @@ module.exports = {
       collapsible: false,
       items: [
         {
-          type: "category",
+          type: "doc",
           label: "🦜🛠️ LangSmith",
-          collapsed: true,
-          items: [
-            {
-              type: "autogenerated",
-              dirName: "langsmith",
-            },
-          ],
-          link: {
-            type: "doc",
-            id: "langsmith/index",
-          },
+          id: "langsmith/index",
         },
         "langgraph",
         "langserve",
       ],
     },
+    {
+      type: "category",
+      label: "Versions",
+      collapsed: false,
+      collapsible: false,
+      items: [
+        {
+          type: "autogenerated",
+          dirName: "versions",
+        }
+      ],
+    },
     "security",
   ],
   integrations: [