Cloudflare Workers Paid plan has no spending cap, making it vulnerable to unexpectedly high bills from bot attacks or buggy code. While Workers requests themselves are cheap at $0.30 per million, costs escalate steeply when Workers interact with other services like D1, R2, or KV; a real case saw a $4,868 bill from database write bugs. Other platforms like Vercel and Netlify offer native spending caps or rate limits, though coverage varies by service.
A developer's Vercel bill increased 10x due to over 1 million requests from Meta's bot crawler targeting a preview deployment shared on WhatsApp. The unexpected charges weren't from user traffic but from Meta's aggressive crawling, and Vercel declined to assist with the bill.