LarkMCP

A powerful Model Context Protocol (MCP) server that exposes Lark OpenAPI documentation and API endpoints as structured, machine-consumable resources and tools.
Designed for seamless integration with LLMs, automation agents, and advanced developer workflows.

Feishu（飞书）対応

• 環境変数 LARK_ORIGIN を feishu に設定することで、Lark（グローバル）だけでなく Feishu（中国版）API・ドキュメントにも対応できます。
• OAuth 認証・API リクエスト・ドキュメント取得時に自動的に open.feishu.cn ドメインや中国語リソースを利用します。
• 例: Feishu で起動する場合

  LARK_ORIGIN=feishu node index.js
  

• デフォルト（Lark グローバル）は LARK_ORIGIN を省略または lark にしてください。

Usage

You can run the MCP server directly via npx (after publishing to npm):

npx @yuki-js/larkmcp

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Features

• MCP Server: Provides Lark documentation and API access via the Model Context Protocol.
• Lark Docs as Resources: Full index of Lark OpenAPI documentation available as a CSV resource.
• Fetch Lark Docs: Retrieve any Lark documentation page as structured JSON, ready for LLM consumption.
• User OAuth & API Proxy: Authenticate via OAuth and proxy requests to Lark OpenAPI endpoints.
• Extensible: Easily add new tools or resources for your own LLM/MCP workflows.
• Modern Node.js: Built with ES modules, async/await, and strong typing via Zod.

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Architecture

+-------------------+      MCP Protocol      +-----------------------------+
|   LLM / Client    | <------------------->  |  Lark OpenAPI Docs MCP      |
+-------------------+                        +-----------------------------+
                                                  |   |   |   |
                                                  |   |   |   |
                                                  v   v   v   v
                                         [Lark Docs] [Lark API] [OAuth]

• MCP Server: Handles all requests via the Model Context Protocol (stdio transport).
• Tools: Expose Lark doc fetch, user login, and API proxy as callable MCP tools.
• Resources: Serve a full CSV index of Lark documentation.

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Getting Started

Prerequisites

• Node.js v22+ recommended
• npm

Installation

git clone https://github.com/yuki-js/larkmcp.git
cd larkmcp
npm install @yuki-js/larkmcp

Running the MCP Server

node index.js

The server will start and listen for MCP stdio connections.

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Usage

You can connect to this MCP server from any MCP-compatible client, LLM, or automation agent.

Example: Fetching Lark Documentation

1. List all available Lark docs

Access the resource:

Resource URI: file://a-full-list-of-available-lark-document.csv/
Description: CSV file listing all available Lark documentation pages.

2. Fetch a specific Lark doc as JSON

Call the fetch_lark_doc tool:

{
  "tool": "fetch_lark_doc",
  "arguments": {
    "url": "https://open.larksuite.com/document/server-docs/docs/docs/docx-v1/document/list"
  }
}

3. Authenticate and Call Lark API

• Use the login_user tool to start OAuth and obtain a user access token.
• Use the test_lark_api tool to call any Lark OpenAPI endpoint.

Example:

{
  "tool": "login_user",
  "arguments": { "step": "start" }
}

Then poll for completion:

{
  "tool": "login_user",
  "arguments": { "step": "poll" }
}

Once authenticated, call the API:

{
  "tool": "test_lark_api",
  "arguments": {
    "endpoint": "/open-apis/contact/v3/user/me",
    "method": "GET"
  }
}

---

MCP Tools & Resources

Tools

fetch_lark_doc

• Description: Fetches a Lark documentation page as raw JSON.
• Arguments:
  • url (string): Human-facing Lark doc URL or path.
• Returns: JSON with doc content and metadata.

login_user

• Description: Initiates OAuth login flow for Lark API.
• Arguments:
  • step ("start" | "poll"): Start OAuth or poll for completion.
• Returns: OAuth URL (start) or access token (poll).

test_lark_api

• Description: Calls any Lark OpenAPI endpoint with the authenticated user.
• Arguments:
  • endpoint (string): Lark API endpoint path.
  • method (string, optional): HTTP method (default: GET).
  • body (object, optional): Request body for POST/PUT.
• Returns: API response (status, headers, body).

Resources

a-full-list-of-available-lark-document

• URI: file://a-full-list-of-available-lark-document.csv/
• Description: CSV file listing all available Lark documentation pages.

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Developer Experience

Recommended VSCode Extensions

• ESLint
• Prettier - Code formatter

推奨拡張は .vscode/extensions.json でも自動提案されます。

Code Linting & Formatting

• 静的解析:

  npm run lint
  

• コード整形:

  npm run format
  

.eslintrc.json でESLintルールをカスタマイズできます。

Prettierの設定はプロジェクトで強制していません。各自の好みに合わせて.prettierrcを編集・利用してください（デフォルトは空設定です）。

---

Development

Project Structure

.
├── index.js
├── package.json
├── server/
│   ├── mcpServer.js
│   ├── resources/
│   │   └── larkDocIndex.js
│   └── tools/
│       ├── fetchLarkDoc.js
│       ├── loginUser.js
│       └── testLarkApi.js
├── data/
│   └── a-full-list-of-available-lark-document.csv
└── utils/

Adding New Tools/Resources

• Implement your tool/resource in server/tools/ or server/resources/.
• Register it in server/mcpServer.js.

Contributing

Pull requests and issues are welcome!
Please open an issue to discuss your ideas or report bugs.

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License

This project is licensed under the ISC License.

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Acknowledgements

• Lark Open Platform
• Model Context Protocol (MCP)
• Zod