compress_local_image

Instructions

Implementation Reference

• src/tools.ts:119-171 (handler)

  Primary handler function that executes the image compression logic using Tinify: loads image, preserves metadata if specified, converts format if needed, determines output path (auto-appending _compressed), saves file, and returns original/compressed sizes and ratio.

  async function handleCompressLocalImageTool({
    imagePath,
    outputPath,
    outputFormat,
    preserveMetadata,
  }: {
    imagePath: string;
    outputPath?: string;
    outputFormat?: SupportedImageTypes;
    preserveMetadata?: string[];
  }) {
    const originalSize = fs.statSync(imagePath).size;
    tinify.key = config.apiKey!;
    let source = tinify.fromFile(imagePath);
  
    if (preserveMetadata?.length) {
      source = source.preserve(...preserveMetadata);
    }
  
    let ext = path.extname(imagePath).slice(1);
  
    if (outputFormat) {
      source.convert({
        type: outputFormat,
      });
      ext = outputFormat.split('/')[1];
    }
  
    let dest = outputPath;
    if (!dest) {
      const dir = path.dirname(imagePath);
      const basename = path.basename(imagePath, path.extname(imagePath));
      dest = path.join(dir, `${basename}.${ext}`);
    }
  
    // add _compressed to the filename
    const destDir = path.dirname(dest);
    const destBasename = path.basename(dest, path.extname(dest));
    if (!destBasename.endsWith('_compressed')) {
      dest = path.join(destDir, `${destBasename}_compressed.${ext}`);
    }
  
    await source.toFile(dest);
  
    const compressedSize = fs.statSync(dest).size;
    const compressionRatio = (originalSize - compressedSize) / originalSize;
  
    return {
      originalSize,
      compressedSize,
      compressionRatio,
    };
  }

• src/tools.ts:17-50 (schema)

  Tool schema definition including name, description, and inputSchema with properties for imagePath (required), outputPath, outputFormat (enum from SUPPORTED_IMAGE_TYPES), and preserveMetadata.

  const COMPRESS_LOCAL_IMAGE_TOOL: Tool = {
    name: 'compress_local_image',
    description: 'Compress a local image file',
    inputSchema: {
      type: 'object',
      properties: {
        imagePath: {
          type: 'string',
          description: 'The ABSOLUTE path to the image file to compress',
          example: '/Users/user/Downloads/image.jpg',
        },
        outputPath: {
          type: 'string',
          description: 'The ABSOLUTE path to save the compressed image file',
          example: '/Users/user/Downloads/image_compressed.jpg',
        },
        outputFormat: {
          type: 'string',
          description: 'The format to save the compressed image file',
          enum: SUPPORTED_IMAGE_TYPES,
          example: 'image/jpeg',
        },
        preserveMetadata: {
          type: 'array',
          description: 'The metadata to preserve in the image file',
          items: {
            type: 'string',
            enum: ['copyright', 'creation', 'location'],
          },
        },
      },
      required: ['imagePath'],
    },
  };

• src/tools.ts:117-117 (registration)

  Registration of the compress_local_image tool (via COMPRESS_LOCAL_IMAGE_TOOL) in the exported TOOLS array for MCP tool discovery.

  export const TOOLS = [COMPRESS_LOCAL_IMAGE_TOOL, COMPRESS_REMOTE_IMAGE_TOOL, RESIZE_IMAGE_TOOL];

• src/tools.ts:244-261 (registration)

  Registration of the tool handler in TOOL_HANDLERS object, which extracts arguments, calls the core handler, and formats the MCP response with JSON stringified results.

  compress_local_image: async (request) => {
    const result = await handleCompressLocalImageTool(
      request.params.arguments as {
        imagePath: string;
        outputPath?: string;
        outputFormat?: SupportedImageTypes;
      },
    );
    return {
      content: [
        {
          type: 'text',
          text: JSON.stringify(result, null, 2),
        },
      ],
      metadata: {},
    };
  },

• src/tools.ts:9-15 (helper)

  Helper constant defining supported image MIME types used in inputSchema enum and output format handling.

  const SUPPORTED_IMAGE_TYPES: SupportedImageTypes[] = [
    'image/jpeg',
    'image/png',
    'image/webp',
    'image/jpg',
    'image/avif',
  ];