Image Worker MCP

import { ErrorCode, McpError } from '@modelcontextprotocol/sdk/types.js'; import fetch from 'node-fetch'; import { SUPPORTED_INPUT_FORMATS, SUPPORTED_OUTPUT_FORMATS } from './constants'; /** * Validates if the provided format is supported for input */ export function isValidInputFormat(format: string): boolean { return SUPPORTED_INPUT_FORMATS.includes(format.toLowerCase()); } /** * Validates if the provided format is supported for output */ export function isValidOutputFormat(format: string): boolean { return SUPPORTED_OUTPUT_FORMATS.includes(format.toLowerCase()); } /** * Validates if the provided dimensions are valid */ export function isValidDimensions(width?: number, height?: number): boolean { if (width !== undefined && (width <= 0 || width > 10000)) { return false; } if (height !== undefined && (height <= 0 || height > 10000)) { return false; } return true; } /** * Validates if the provided quality is valid */ export function isValidQuality(quality?: number): boolean { if (quality !== undefined && (quality < 1 || quality > 100)) { return false; } return true; } /** * Extracts the file extension from a filename */ export function getFileExtension(filename: string): string { const parts = filename.split('.'); return parts.length > 1 ? parts.pop()!.toLowerCase() : ''; } /** * Converts a base64 string to a Buffer */ export function base64ToBuffer(base64: string): Buffer { // Remove data URL prefix if present const base64Data = base64.replace(/^data:image\/\w+;base64,/, ''); return Buffer.from(base64Data, 'base64'); } /** * Converts a Buffer to a base64 string */ export function bufferToBase64(buffer: Buffer, mimeType: string): string { return `data:${mimeType};base64,${buffer.toString('base64')}`; } /** * Normalizes a file path by handling escaped characters and spaces * * This function handles cases like 'a\ name.png' by converting them to 'a name.png' */ export function normalizeFilePath(filePath: string): string { // Replace escaped spaces (\ ) with actual spaces let normalizedPath = filePath.replace(/\\+ /g, ' '); // Replace other common escaped characters normalizedPath = normalizedPath .replace(new RegExp("\\\\+'", 'g'), "'") .replace(new RegExp('\\\\+"', 'g'), '"') .replace(new RegExp('\\\\+`', 'g'), '`') .replace(new RegExp('\\\\+\\(', 'g'), '(') .replace(new RegExp('\\\\+\\)', 'g'), ')') .replace(new RegExp('\\\\+\\[', 'g'), '[') .replace(new RegExp('\\\\+\\]', 'g'), ']') .replace(new RegExp('\\\\+\\{', 'g'), '{') .replace(new RegExp('\\\\+\\}', 'g'), '}'); return normalizedPath; } /** * Fetches an image from a URL and returns it as a Buffer */ export async function fetchImageFromUrl(url: string): Promise<Buffer> { try { const response = await fetch(url); // Check if the response is successful if (!response.ok) { throw new McpError( ErrorCode.InvalidParams, `Failed to fetch image from URL: ${url}, status code: ${response.status}`, ); } // Check if the content type is an image const contentType = response.headers.get('content-type'); if (!contentType || !contentType.startsWith('image/')) { throw new McpError( ErrorCode.InvalidParams, `URL does not point to an image: ${url}, content-type: ${contentType}`, ); } // Get the response as an ArrayBuffer and convert to Buffer const arrayBuffer = await response.arrayBuffer(); return Buffer.from(arrayBuffer); } catch (error) { if (error instanceof McpError) { throw error; } throw new McpError( ErrorCode.InternalError, `Error fetching image from URL: ${error instanceof Error ? error.message : String(error)}`, ); } }