Image Analysis MCP Server

#!/usr/bin/env node import { Server } from '@modelcontextprotocol/sdk/server/index.js'; import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js'; import { CallToolRequestSchema, ErrorCode, ListToolsRequestSchema, McpError, } from '@modelcontextprotocol/sdk/types.js'; import { OpenAI } from 'openai'; import axios from 'axios'; import * as dotenv from 'dotenv'; import * as fs from 'fs'; // Import fs for file reading import * as path from 'path'; // Import path for path operations import * as os from 'os'; // Import os module import * as mime from 'mime-types'; // Revert to import statement // Load environment variables from .env file dotenv.config(); // Get OpenAI API key from environment variables const OPENAI_API_KEY = process.env.OPENAI_API_KEY; if (!OPENAI_API_KEY) { throw new Error('OPENAI_API_KEY environment variable is required'); } // Initialize OpenAI client const openai = new OpenAI({ apiKey: OPENAI_API_KEY, }); // --- Argument Type Guards --- const isValidAnalyzeImageArgs = ( args: any ): args is { imageUrl: string } => typeof args === 'object' && args !== null && typeof args.imageUrl === 'string'; const isValidAnalyzeImagePathArgs = ( args: any ): args is { imagePath: string } => // New type guard for path tool typeof args === 'object' && args !== null && typeof args.imagePath === 'string'; // --- End Argument Type Guards --- class ImageAnalysisServer { private server: Server; constructor() { this.server = new Server( { name: 'image-analysis-server', version: '1.1.0', // Version bump }, { capabilities: { tools: {}, }, } ); this.setupToolHandlers(); // Error handling this.server.onerror = (error) => console.error('[MCP Error]', error); process.on('SIGINT', async () => { await this.server.close(); process.exit(0); }); } private setupToolHandlers() { // Define tool list this.server.setRequestHandler(ListToolsRequestSchema, async () => ({ tools: [ { name: 'analyze_image', description: 'Receives an image URL and analyzes the image content using GPT-4o-mini', inputSchema: { type: 'object', properties: { imageUrl: { type: 'string', description: 'URL of the image to analyze', }, }, required: ['imageUrl'], }, }, // --- New Tool Definition --- { name: 'analyze_image_from_path', description: 'Loads an image from a local file path and analyzes its content using GPT-4o-mini. AI assistants need to provide a valid path for the server execution environment (e.g., Linux path if the server is running on WSL).', inputSchema: { type: 'object', properties: { imagePath: { type: 'string', description: 'Local file path of the image to analyze (must be accessible from the server execution environment)', }, }, required: ['imagePath'], }, }, // --- End New Tool Definition --- ], })); // Tool execution handler this.server.setRequestHandler(CallToolRequestSchema, async (request) => { const toolName = request.params.name; const args = request.params.arguments; try { let analysis: string; if (toolName === 'analyze_image') { if (!isValidAnalyzeImageArgs(args)) { throw new McpError( ErrorCode.InvalidParams, 'Invalid arguments for analyze_image: imageUrl (string) is required' ); } const imageUrl = args.imageUrl; await this.validateImageUrl(imageUrl); // Validate URL accessibility analysis = await this.analyzeImageWithGpt4({ type: 'url', data: imageUrl }); } else if (toolName === 'analyze_image_from_path') { if (!isValidAnalyzeImagePathArgs(args)) { throw new McpError( ErrorCode.InvalidParams, 'Invalid arguments for analyze_image_from_path: imagePath (string) is required' ); } const imagePath = args.imagePath; // Basic security check: prevent absolute paths trying to escape common roots (adjust as needed) // This is a VERY basic check and might need refinement based on security requirements. if (path.isAbsolute(imagePath) && !imagePath.startsWith(process.cwd()) && !imagePath.startsWith(os.homedir()) && !imagePath.startsWith('/mnt/')) { // Allow relative paths, paths within cwd, home, or WSL mounts. Adjust if needed. console.warn(`Potential unsafe path access attempt blocked: ${imagePath}`); throw new McpError(ErrorCode.InvalidParams, 'Invalid or potentially unsafe imagePath provided.'); } const resolvedPath = path.resolve(imagePath); // Resolve relative paths if (!fs.existsSync(resolvedPath)) { throw new McpError(ErrorCode.InvalidParams, `File not found at path: ${resolvedPath}`); } const imageDataBuffer = fs.readFileSync(resolvedPath); const base64String = imageDataBuffer.toString('base64'); const mimeType = mime.lookup(resolvedPath) || 'application/octet-stream'; // Detect MIME type or default if (!mimeType.startsWith('image/')) { throw new McpError(ErrorCode.InvalidParams, `File is not an image: ${mimeType}`); } analysis = await this.analyzeImageWithGpt4({ type: 'base64', data: base64String, mimeType: mimeType }); } else { throw new McpError( ErrorCode.MethodNotFound, `Unknown tool: ${toolName}` ); } // Return successful analysis return { content: [ { type: 'text', text: analysis, }, ], }; } catch (error) { console.error(`Error calling tool ${toolName}:`, error); // Return error content return { content: [ { type: 'text', text: `Tool execution error (${toolName}): ${error instanceof Error ? error.message : String(error)}`, }, ], isError: true, }; } }); } // Method to check if the image URL is valid (existing) private async validateImageUrl(url: string): Promise<void> { try { const response = await axios.head(url); const contentType = response.headers['content-type']; if (!contentType || !contentType.startsWith('image/')) { throw new Error(`URL is not an image: ${contentType}`); } } catch (error) { if (axios.isAxiosError(error)) { throw new Error(`Cannot access image URL: ${error.message}`); } throw error; } } // Method to analyze images with GPT-4o-mini (modified: accepts URL or Base64) private async analyzeImageWithGpt4( imageData: { type: 'url', data: string } | { type: 'base64', data: string, mimeType: string } ): Promise<string> { try { let imageInput: any; if (imageData.type === 'url') { imageInput = { type: 'image_url', image_url: { url: imageData.data } }; } else { // Construct data URI for OpenAI API imageInput = { type: 'image_url', image_url: { url: `data:${imageData.mimeType};base64,${imageData.data}` } }; } const response = await openai.chat.completions.create({ model: 'gpt-4o-mini', messages: [ { role: 'system', content: 'Analyze the image content in detail and provide an explanation in English.', }, { role: 'user', content: [ { type: 'text', text: 'Please analyze the following image and explain its content in detail.' }, imageInput, // Use the constructed image input ], }, ], max_tokens: 1000, }); return response.choices[0]?.message?.content || 'Could not retrieve analysis results.'; } catch (error) { console.error('OpenAI API error:', error); throw new Error(`OpenAI API error: ${error instanceof Error ? error.message : String(error)}`); } } async run() { const transport = new StdioServerTransport(); await this.server.connect(transport); console.error('Image Analysis MCP server (v1.1.0) running on stdio'); // Updated version } } const server = new ImageAnalysisServer(); server.run().catch(console.error);