langchain - 💡(How to fix) Fix configurable data is no longer included in the metadata. [3 comments, 3 participants]

Submission checklist

• This is a bug, not a usage question.
• I added a clear and descriptive title that summarizes this issue.
• I used the GitHub search to find a similar question and didn't find it.
• I am sure that this is a bug in LangChain rather than my code.
• The bug is not resolved by updating to the latest stable version of LangChain (or the specific integration package).
• This is not related to the langchain-community package.
• I posted a self-contained, minimal, reproducible example. A maintainer can copy it and run it AS IS.

Package (Required)

• langchain
• langchain-openai
• langchain-anthropic
• langchain-classic
• langchain-core
• langchain-model-profiles
• langchain-tests
• langchain-text-splitters
• langchain-chroma
• langchain-deepseek
• langchain-exa
• langchain-fireworks
• langchain-groq
• langchain-huggingface
• langchain-mistralai
• langchain-nomic
• langchain-ollama
• langchain-openrouter
• langchain-perplexity
• langchain-qdrant
• langchain-xai
• Other / not sure / general

Related Issues / PRs

Since langchain-core 1.3.0, configurable section is no longer stored in the metadata due to commit af4d711a2f2ebcaa524af34abb0262dfdac9678a

Reproduction Steps / Example Code (Python)

session_store = {}
def get_session_history(session_id):
    if session_id not in session_store:
        session_store[session_id] = ChatMessageHistory()
    return session_store[session_id]
def demo_langchain_history_stream():
    session_id = "demo_session_123123"
    prompt = ChatPromptTemplate.from_messages([
        ("system", "你是一个乐于助人的助手"),
        ("human", "{input}"),
    ])
    chain = prompt | llm | StrOutputParser()
    agent = RunnableWithMessageHistory(chain, get_session_history,
                                       input_key="user",
                                       output_key="assistant", history_key="session_id")

    gen = agent.stream(
        {'input': "你是什么大模型"},
        config={"configurable": {"session_id": session_id}},
    )
    for chunk in gen:
        print(chunk)

Error Message and Stack Trace (if applicable)

Description

langchain-core 1.2.31 can include configurable data.

System Info

System Information

OS: Linux OS Version: #1 SMP Debian 5.10.251-3 (2026-04-30) Python Version: 3.12.13 (main, May 12 2026, 10:24:44) [GCC 10.2.1 20210110]

Package Information

langchain_core: 1.3.3 langchain: 1.2.15 langchain_community: 0.4.1 langsmith: 0.8.3 langchain_classic: 1.0.7 langchain_openai: 1.2.1 langchain_protocol: 0.0.15 langchain_text_splitters: 1.1.2 langgraph_sdk: 0.3.14

Optional packages not installed

deepagents deepagents-cli

Other Dependencies

aiohttp: 3.13.5 dataclasses-json: 0.6.7 httpx: 0.28.1 httpx-sse: 0.4.3 jsonpatch: 1.33 langgraph: 1.1.10 numpy: 2.4.4 openai: 2.36.0 orjson: 3.11.9 packaging: 26.2 pydantic: 2.13.4 pydantic-settings: 2.14.1 PyYAML: 6.0.3 pyyaml: 6.0.3 requests: 2.33.1 requests-toolbelt: 1.0.0 SQLAlchemy: 2.0.49 sqlalchemy: 2.0.49 tenacity: 9.1.4 tiktoken: 0.12.0 typing-extensions: 4.15.0 uuid-utils: 0.15.0 xxhash: 3.7.0 zstandard: 0.25.0