openfoodfacts-mcp

Instructions

Implementation Reference

• src/tools/upload-image.ts:38-49 (handler)

  The handler function for the upload_image tool. It processes the base64 input, constructs the multipart form data, and submits it to the OFF API.

  async (args) => {
  	const imageBuffer = Buffer.from(args.image_data, 'base64');
  
  	const formData = new FormData();
  	formData.set('code', args.barcode);
  	formData.set('imagefield', `${args.imagefield}_${args.lc}`);
  	formData.set(`imgupload_${args.imagefield}_${args.lc}`, new Blob([imageBuffer]), 'image.jpg');
  
  	const data = await offPostMultipart(config, '/cgi/product_image_upload.pl', formData);
  
  	return jsonResult(data as Record<string, unknown>);
  },

• src/tools/upload-image.ts:8-25 (schema)

  The Zod schema defining the input arguments for the upload_image tool.

  const inputSchema = strictSchemaWithAliases(
  	{
  		barcode: z.string().describe('Product barcode'),
  		imagefield: z.enum([
  			'front',
  			'ingredients',
  			'nutrition',
  			'packaging',
  			'other',
  		]).describe('Image type'),
  		image_data: z.string().describe('Base64-encoded image data (JPEG or PNG)'),
  		lc: z.string().default('en').describe('Language code for the image (default: en)'),
  	},
  	{
  		code: 'barcode',
  		type: 'imagefield',
  	},
  );

• src/tools/upload-image.ts:27-51 (registration)

  Function to register the 'upload_image' tool with the MCP server.

  export function registerUploadImage(server: McpServer, config: Config): void {
  	server.registerTool(
  		'upload_image',
  		{
  			title: 'Upload product image',
  			description: 'Upload a product image to Open Food Facts. Requires OFF_USER_ID and OFF_PASSWORD.\n\nPrefer more photos over fewer. Panels with text (ingredients, nutrition, certifications, recycling instructions) are highest value as OFF can OCR them. Plain sides with just a colour or logo are lowest value but still worth uploading if you have them.\n\nUse the most appropriate imagefield (front, ingredients, nutrition, packaging). Use "other" for additional photos — this uploads without selecting the image as a display image, which is useful when a good display image already exists or for supplementary angles.\n\nThe OFF server auto-selects images for front/nutrition/ingredients/packaging on upload unless one is already selected. If you get "status not ok" but a positive imgid, the image uploaded successfully but was not selected (e.g. a display image already exists).\n\nFor images on disk, base64-encode them first (e.g. via shell: `base64 -i photo.jpg`).',
  			inputSchema,
  			annotations: {
  				readOnlyHint: false,
  			},
  		},
  		async (args) => {
  			const imageBuffer = Buffer.from(args.image_data, 'base64');
  
  			const formData = new FormData();
  			formData.set('code', args.barcode);
  			formData.set('imagefield', `${args.imagefield}_${args.lc}`);
  			formData.set(`imgupload_${args.imagefield}_${args.lc}`, new Blob([imageBuffer]), 'image.jpg');
  
  			const data = await offPostMultipart(config, '/cgi/product_image_upload.pl', formData);
  
  			return jsonResult(data as Record<string, unknown>);
  		},
  	);
  }