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EVENT / TOPICHistorical

LangChain Integrates MCP Protocol with Stateless Mode and Elicitation Support

1 reports1 sources10/13/2026 updated

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LangChain has moved the core of the MCP protocol into its main package (langchain.mcp), eliminating the need for the separate langchain-mcp-adapters library. The protocol has been rewritten on top of FastMCP, and a new stateless core mode replaces the previous session‑based interactions that were used for every MCP call. In addition to the stateless change, LangChain now supports elicitation interruption: when a server initiates a query mid‑conversation, the request can be retried or aborted through LangGraph’s interruption handling. A client‑side cache has also been added to reduce redundant network traffic. These updates streamline MCP usage, improve flexibility for dynamic dialogue, and enhance performance by removing session overhead and adding caching capabilities.

Written with AI from the reporting · updated 10/14/2026

Latest developmentOct 14, 03:56
LangChain integrates Model Context Protocol into main package with stateless core and elicitation support
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  1. 1Unclassified fact stationJul 28, 00:00recorded Oct 14, 22:22single sourcerevised

    MCP 协议在 LangChain 中实现 stateless 协议与 elicitation 支持

    Read original source ↗ LangChain BlogReplay this moment in the explorer
    Evidence & revisions · 1 source records
    Subject：
    LangChain
    Action：
    发布 MCP 协议新版本支持，包括 stateless 核心、elicitation 中断、客户端缓存及 FastMCP 4 升级
    Object：
    MCP 协议与 LangChain 整合
    Occurred (fact side)：
    Jul 28, 00:00
    LangChain Blog ↗Report pageRevision 2 · currently revised
    Published (valid side)：
    Oct 14, 03:56
    First seen (known side)：
    Oct 14, 22:22
    Fact stationSingle source · one-sided claimRevised

    Copy may have been revised later; time replay is bounded. Layer labels group reading only, not causation between layers.

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Oct 14
  1. LangChain BlogRelated fact: single sourceSource report revised
    LangChain integrates Model Context Protocol into main package with stateless core and elicitation support

    Report first recorded Oct 14, 22:22

    LangChain has revamped its support for Model Context Protocol (MCP) by moving it into the main package (langchain.mcp) built on FastMCP, replacing the separate langchain-mcp-adapters install. This update supports elicitation via interrupts and client-side caching. The new stateless MCP spec eliminates session pinning, improving server reliability and scalability, and allows tool lists to be cacheable, preventing re-fetching on every run. MCP tool calls from ChatGPT users have increased 98x across 2026, more than doubling in August alone.

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