Signal Sideband collects URLs shared in group chats and fetches OG metadata for previews. Problem: X/Twitter links return nothing useful behind their auth wall. The preview cards were blank.

the fix

Grok (xAI) has native access to X/Twitter content, so it’s the right tool for summarizing those links. The preview worker now:

  1. Skips HTML scrape for x.com / twitter.com domains (pointless)
  2. Sends the raw URL to Grok with sender context
  3. Gets back a one-sentence summary + 2-4 topic tags
  4. For non-Twitter links, uses the scraped OG metadata as context for better summaries

The prompt is simple — JSON response format, content-focused tags, include who shared it: