Lens

What is Lens?

Lens is a high-performance image proxy and web services toolkit built with modern TypeScript. It provides a comprehensive suite of web utilities including image processing, screenshot capture, font serving, and more, all exposed as an MCP server via JSON-RPC 2.0 over HTTP.

How to use Lens?

Clone the repository, install dependencies with pnpm, copy .env.example to .env, and run pnpm dev to start the development server on http://localhost:3000. For MCP server use, configure Claude Desktop with the URL https://api.bysages.com/mcp in claude_desktop_config.json.

Key features of Lens

• Image proxy with IPX-powered resize, format conversion, and optimization
• Website screenshot capture with Playwright-aligned options and caching
• Article content extraction (Markdown/HTML) via the Reader service
• Google Fonts compatible API (v1 and v2) with variable font support
• Dynamic Open Graph image generation
• Smart favicon extraction from multiple sources with fallback
• Cached Gravatar avatar proxy supporting email or hash input

Use cases of Lens

• Transform and optimize images on-the-fly for web performance
• Capture screenshots of websites for previews or archiving
• Extract clean article content from any URL for reading
• Serve custom fonts with a Google Fonts compatible endpoint
• Generate dynamic OG images for social media sharing
• Retrieve Gravatar avatars with caching and drop-in API replacement

FAQ from Lens

What is the MCP server in Lens?

Lens exposes all its services as tools via a JSON-RPC 2.0 MCP server endpoint (POST /mcp), allowing AI assistants like Claude to use image processing, screenshots, content extraction, and more.

What runtime dependencies does Lens require?

Lens requires Node.js 22+ and pnpm 10+ (or npm). Optional Redis caching significantly improves performance; without Redis, services degrade gracefully.

How are responses cached in Lens?

Cached responses include X-Cache headers (HIT/MISS) and ETag headers for conditional 304 responses. Most services cache results for 24 hours (screenshots, OG images) or 30 days (favicons).

What transports and authentication does Lens support?

Lens runs over HTTP. No authentication is mentioned in the README; security is handled via optional ALLOWED_DOMAINS environment variable for the image proxy. The MCP server uses HTTP POST.

Are there any rate limiting features?

Yes, Lens includes rate limiting for expensive operations like screenshot capture to protect server resources.