MCP Docs RAG Server

Instructions

Implementation Reference

• src/index.ts:553-583 (handler)

  Handler for executing the 'add_text_file' tool. Validates inputs, calls downloadFile helper to add the text file as a document, and returns success or 'already exists' message.

  case "add_text_file": {
    const fileUrl = String(request.params.arguments?.file_url);
    const documentName = String(request.params.arguments?.document_name);
    
    if (!fileUrl) {
      throw new Error("File URL is required");
    }
    
    if (!documentName) {
      throw new Error("Document name is required");
    }
    
    const result = await downloadFile(fileUrl, documentName);
    
    // If document already exists, inform the user without updating
    if (result.exists) {
      return {
        content: [{
          type: "text",
          text: `Document '${result.name}' already exists. Please use list_documents to view existing documents.`
        }]
      };
    }
    
    return {
      content: [{
        type: "text",
        text: `Added document '${result.name}' with content from ${fileUrl}. The index will be created when you query this document for the first time.`
      }]
    };
  }

• src/index.ts:411-428 (registration)

  Registration of the 'add_text_file' tool in the ListToolsRequestSchema handler, defining its name, description, and input schema.

  {
    name: "add_text_file",
    description: "Add a text file to the docs directory with a specified name. Please do not use 'docs' in the document name.",
    inputSchema: {
      type: "object",
      properties: {
        file_url: {
          type: "string",
          description: "URL of the text file to download"
        },
        document_name: {
          type: "string",
          description: "Name of the document (will be used as directory name). Choose a descriptive name rather than using the URL filename (e.g. 'hono' instead of 'llms-full.txt')"
        }
      },
      required: ["file_url", "document_name"]
    }
  }

• src/index.ts:263-285 (helper)

  Helper function downloadFile that implements the core logic of downloading a text file from URL to a document directory as 'index.txt', checking if already exists.

  export async function downloadFile(fileUrl: string, documentName: string): Promise<{ name: string; exists: boolean }> {
    // ドキュメント用のディレクトリを作成
    const docDir = path.join(DOCS_PATH, documentName);
    
    // ディレクトリが存在する場合は更新せずに通知
    if (fs.existsSync(docDir)) {
      return { name: documentName, exists: true };
    }
    
    // ディレクトリが存在しない場合は作成
    fs.mkdirSync(docDir, { recursive: true });
    
    // ファイル名を取得（URLのパス部分の最後）
    const fileName = path.basename(fileUrl);
    
    // index.txtとしてファイルを保存
    const filePath = path.join(docDir, 'index.txt');
    
    // ファイルをダウンロード
    await execAsync(`cd "${docDir}" && wget -O "index.txt" ${fileUrl}`);
    
    return { name: documentName, exists: false };
  }