og-renderer

Serverless OG image renderer for social media link previews. Deploys as a Vercel function.

How it works

1. Receives a ?u= query parameter with an encoded URL
2. Launches headless Chromium via Puppeteer and navigates to the URL
3. Waits for the #card element to appear
4. Screenshots the element and processes it with Sharp (resized to 1200×630px JPEG)
5. Returns the image with aggressive cache headers

API

GET /render?u=<encoded-url>

Only URLs from brainrot.girard-davila.net are allowed (SSRF protection). All other origins return 403.

Response headers:

• Cache-Control: public, max-age=86400, stale-while-revalidate=604800

Tech stack

• Node.js 22, TypeScript
• @sparticuz/chromium — serverless-optimized Chromium
• puppeteer-core — headless browser control
• sharp — image resizing and JPEG encoding
• Vercel — serverless hosting

Local development

npm install
vercel dev
# → http://localhost:3000/render?u=<encoded-url>

Deployment

vercel deploy         # preview
vercel deploy --prod  # production