Simple Document Processing MCP Server

Instructions

Implementation Reference

• src/tools/txtTools.ts:204-252 (handler)

  Implements the text_diff tool: reads two UTF-8 text files, computes line-level differences using the 'diff' library, formats the diff output, and saves it to a new file in the specified output directory.

  export async function compareTexts(
    file1Path: string,
    file2Path: string,
    outputDir: string
  ) {
    try {
      console.error(`Starting text comparison...`);
      console.error(`File 1: ${file1Path}`);
      console.error(`File 2: ${file2Path}`);
      console.error(`Output directory: ${outputDir}`);
  
      // 確保輸出目錄存在
      try {
        await fs.access(outputDir);
        console.error(`Output directory exists: ${outputDir}`);
      } catch {
        console.error(`Creating output directory: ${outputDir}`);
        await fs.mkdir(outputDir, { recursive: true });
        console.error(`Created output directory: ${outputDir}`);
      }
  
      const uniqueId = generateUniqueId();
      const text1 = await fs.readFile(file1Path, "utf-8");
      const text2 = await fs.readFile(file2Path, "utf-8");
  
      const diff = diffLines(text1, text2);
      const diffResult = diff
        .map((part) => {
          const prefix = part.added ? "+ " : part.removed ? "- " : "  ";
          return prefix + part.value;
        })
        .join("");
  
      const outputPath = path.join(outputDir, `diff_${uniqueId}.txt`);
      await fs.writeFile(outputPath, diffResult);
      console.error(`Written diff result to ${outputPath}`);
  
      return {
        success: true,
        data: `Successfully compared texts: ${outputPath}`,
      };
    } catch (error) {
      console.error(`Error in compareTexts:`, error);
      return {
        success: false,
        error: error instanceof Error ? error.message : "Unknown error",
      };
    }
  }

• src/tools/txtTools.ts:61-82 (schema)

  Defines the Tool object for 'text_diff' including name, description, and input schema specifying two file paths and output directory.

  export const TEXT_DIFF_TOOL: Tool = {
    name: "text_diff",
    description: "Compare two text files and show differences",
    inputSchema: {
      type: "object",
      properties: {
        file1Path: {
          type: "string",
          description: "Path to the first text file",
        },
        file2Path: {
          type: "string",
          description: "Path to the second text file",
        },
        outputDir: {
          type: "string",
          description: "Directory where diff result should be saved",
        },
      },
      required: ["file1Path", "file2Path", "outputDir"],
    },
  };

• src/index.ts:283-300 (registration)

  In the central CallToolRequestSchema handler, dispatches 'text_diff' calls to the compareTexts function, handles the result, and formats the response.

  if (name === "text_diff") {
    const { file1Path, file2Path, outputDir } = args as {
      file1Path: string;
      file2Path: string;
      outputDir: string;
    };
    const result = await compareTexts(file1Path, file2Path, outputDir);
    if (!result.success) {
      return {
        content: [{ type: "text", text: `Error: ${result.error}` }],
        isError: true,
      };
    }
    return {
      content: [{ type: "text", text: fileOperationResponse(result.data) }],
      isError: false,
    };
  }

• src/index.ts:47-49 (registration)

  Registers the list of all tools (including text_diff via imported tools array) for the ListToolsRequestSchema.

  server.setRequestHandler(ListToolsRequestSchema, async () => ({
    tools,
  }));

• src/tools/_index.ts:9-9 (registration)

  Aggregates and exports the array of all Tool objects, including TEXT_DIFF_TOOL, which is used by the server for listing available tools.

  export const tools = [DOCUMENT_READER_TOOL, PDF_MERGE_TOOL, PDF_SPLIT_TOOL, DOCX_TO_PDF_TOOL, DOCX_TO_HTML_TOOL, HTML_CLEAN_TOOL, HTML_TO_TEXT_TOOL, HTML_TO_MARKDOWN_TOOL, HTML_EXTRACT_RESOURCES_TOOL, HTML_FORMAT_TOOL, TEXT_DIFF_TOOL, TEXT_SPLIT_TOOL, TEXT_FORMAT_TOOL, TEXT_ENCODING_CONVERT_TOOL, EXCEL_READ_TOOL, FORMAT_CONVERTER_TOOL];