LangChain Docs MCP server

Tools provided by LangChain Docs 3

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• query_docs_filesystem_docs_by_lang_chainNo outputSchema

  Run a read-only shell-like query against a virtualized, in-memory filesystem rooted at `/` that contains ONLY the Docs by LangChain documentation pages and OpenAPI specs. This is NOT a shell on any real machine — nothing runs on the user's computer, the server host, or any network. The filesystem is a sandbox backed by documentation chunks. This is how you read documentation pages: there is no separate "get page" tool. To read a page, pass its `.mdx` path to `head` or `cat` — a page at the URL path `/some/page` lives at `/some/page.mdx`. To search the docs with exact keyword or regex matches,

  Input command: string

  • command: stringrequired

    A shell command to run against the virtualized documentation filesystem (e.g., `rg -il "keyword" /`, `tree / -L 2`, `head -80 /path/file.mdx`).

• search_docs_by_lang_chainNo outputSchema

  Search across the Docs by LangChain knowledge base to find relevant information, code examples, API references, and guides. Use this tool when you need to answer questions about Docs by LangChain, find specific documentation, understand how features work, or locate implementation details. The search returns contextual content with titles and direct links to the documentation pages. If you need the full content of a specific page, use the query_docs_filesystem tool to `head` or `cat` the page path (append `.mdx` to the path returned from search — e.g. a result at `/some/page` is read with `head

  Input query: string

  • query: stringrequired

    Search query

• submit_feedbackNo outputSchema

  Report a problem with this documentation site so the docs team can fix it. Use when a documentation page is incorrect, outdated, confusing, incomplete, or has a broken example. This is for feedback about the documentation content itself — not for product support requests or feedback about this tool or assistant.

  Input feedback: string, path: string

  • feedback: stringrequired

    A clear description of the documentation issue or suggestion — what is incorrect, outdated, missing, or confusing.

  • path: stringrequired

    The URL path of the documentation page the feedback is about (the page you were reading, without the `.mdx` extension).

Resources 1

• langchaintext/markdown

  Use when building AI agents, integrating LLMs with tools, managing agent state and memory, deploying agents to production, or tracing and evaluating agent behavior. LangChain is the framework for composing agents from models, tools, and middleware; use it for custom agent architectures, tool integration, and multi-step reasoning workflows.