fix(langchain): removing more v0 content #861

sydney-runkle · 2025-10-13T15:38:00Z

removing v0 content

Copilot

Pull Request Overview

This PR modernizes LangChain's documentation by removing outdated v0 content and updating it to reflect the current middleware-based architecture. The changes reorganize content to improve user experience and maintain consistency across documentation sections.

Key changes:

Refactored middleware patterns from legacy hooks to modern decorator and class-based approaches
Moved "Create tools" section from beginning to end in tools documentation for better information flow
Updated API patterns throughout multiple files to use current middleware architecture

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
`src/oss/langchain/tools.mdx`	Moved "Create tools" section to end and expanded agent data access content
`src/oss/langchain/short-term-memory.mdx`	Updated state management and hooks to use middleware patterns
`src/oss/langchain/runtime.mdx`	Modernized runtime access examples to use middleware instead of hooks
`src/oss/langchain/rag.mdx`	Added missing state_schema property to middleware class
`src/oss/langchain/middleware.mdx`	Reorganized decorator and class-based middleware sections
`src/oss/langchain/context-engineering.mdx`	Complete rewrite to focus on practical middleware-based patterns
`src/oss/langchain/agents.mdx`	Added middleware references and updated hook descriptions

src/oss/langchain/middleware.mdx

github-actions · 2025-10-13T15:39:11Z

Preview ID generated: preview-srchip-1760369918-75ab621

github-actions · 2025-10-13T15:58:04Z

Preview ID generated: preview-srchip-1760371054-ce01201

Copilot

Pull Request Overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (2)

src/oss/langchain/short-term-memory.mdx:67

Missing closing bracket for the messages array in the JavaScript code.

});

src/oss/langchain/context-engineering.mdx:1

The function perform_search is referenced but not defined. This will cause a runtime error when the example is executed. Consider providing a placeholder implementation or noting that it's a stub function.

---

src/oss/langchain/context-engineering.mdx

github-actions · 2025-10-13T16:11:28Z

Preview ID generated: preview-srchip-1760371860-09bf38d

sydney-runkle · 2025-10-13T16:33:07Z

src/oss/langchain/agents.mdx

 For more details on streaming, see [Streaming](/oss/langchain/streaming).
 </Tip>
+
+### Middleware


can add specific code examples here if we want, but I think middleware section makes more sense

github-actions · 2025-10-13T16:50:26Z

Preview ID generated: preview-srchip-1760374199-c008c3d

sydney-runkle · 2025-10-13T16:56:44Z

src/oss/langchain/short-term-memory.mdx

 from langchain.agents import create_agent, AgentState
+from langchain.agents.middleware import AgentMiddleware
 from langgraph.checkpoint.memory import InMemorySaver
+
 class CustomAgentState(AgentState):  # [!code highlight]
    user_id: str  # [!code highlight]
+    preferences: dict  # [!code highlight]
+
+class StateExtensionMiddleware(AgentMiddleware[CustomAgentState]):
+    state_schema = CustomAgentState  # [!code highlight]

 agent = create_agent(
    "openai:gpt-5",
    [get_user_info],
-    state_schema=CustomAgentState,  # [!code highlight]
+    middleware=[StateExtensionMiddleware()],  # [!code highlight]
    checkpointer=InMemorySaver(),
 )


This seems unfortunate to me :/

Also not a great example of state extension? Both of these seem context-y?

src/oss/langchain/short-term-memory.mdx

sydney-runkle · 2025-10-13T16:58:55Z

src/oss/langchain/short-term-memory.mdx

-from langchain_core.messages.utils import count_tokens_approximately
-from langchain.agents import create_agent, AgentState
+from langchain.agents import create_agent
+from langchain.agents.middleware import SummarizationMiddleware


github-actions · 2025-10-13T17:05:57Z

Preview ID generated: preview-srchip-1760375129-9bc72ff

github-actions · 2025-10-13T17:09:22Z

Preview ID generated: preview-srchip-1760375332-0ab38d5

github-actions · 2025-10-13T17:12:46Z

Preview ID generated: preview-srchip-1760375536-7581bf7

github-actions · 2025-10-13T17:14:56Z

Preview ID generated: preview-srchip-1760375669-afa4ae5

github-actions · 2025-10-14T01:46:30Z

Preview ID generated: preview-srchip-1760406357-8eda49f

src/oss/langchain/middleware.mdx

github-actions · 2025-10-14T01:49:47Z

Preview ID generated: preview-srchip-1760406558-ab7c31b

Copilot

Pull Request Overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (2)

src/oss/langchain/middleware.mdx:1

The unreachable return statement has been removed, but the exception handling logic is still incomplete. The retry should continue to the next iteration within the loop rather than falling through.

---

src/oss/langchain/context-engineering.mdx:1

The function perform_search is referenced but not defined. This appears to be a placeholder that should either be implemented or marked as a conceptual example.

---

eyurtsev · 2025-10-14T02:00:05Z

src/oss/langchain/middleware.mdx

+        }
+    return None
+
+# Wrap-style: retry logic


I don't know if "wrap-style" would make sense to folks

eyurtsev · 2025-10-14T02:01:08Z

src/oss/langchain/middleware.mdx

+
+## Decorator-based middleware
+
+For simple middleware that only needs a single hook, decorators provide the quickest way to add functionality:


This might work better as tabs or separate snippets, not sure, but code block is long

removing v0 content

initial fixes

b0dcd02

Copilot AI review requested due to automatic review settings October 13, 2025 15:38

sydney-runkle requested review from katmayb and lnhsingh as code owners October 13, 2025 15:38

github-actions bot added langchain For docs changes to LangChain oss labels Oct 13, 2025

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improving more pages

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nit

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sydney-runkle commented Oct 13, 2025

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sydney-runkle marked this pull request as draft October 13, 2025 16:37

sydney-runkle added 2 commits October 13, 2025 12:47

rewrite section

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patterns

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sydney-runkle commented Oct 13, 2025

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sydney-runkle commented Oct 13, 2025

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some improvements

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little

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output snippet woo

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update size

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sydney-runkle commented Oct 14, 2025

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Update src/oss/langchain/middleware.mdx

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sydney-runkle marked this pull request as ready for review October 14, 2025 01:53

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sydney-runkle merged commit f675574 into main Oct 14, 2025
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sydney-runkle deleted the sr/chipping-at-v1-pages branch October 14, 2025 02:03

mdrxy pushed a commit that referenced this pull request Oct 14, 2025

fix(langchain): removing more v0 content (#861)

f87bbbc

removing v0 content


		## Decorator-based middleware

		For simple middleware that only needs a single hook, decorators provide the quickest way to add functionality:

fix(langchain): removing more v0 content #861

fix(langchain): removing more v0 content #861

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sydney-runkle commented Oct 13, 2025 •

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