Linkup Search API: $20 on Sign-up (Professional Email, Topped Up Monthly)
Linkup
Signing up with a professional email credits your account with $20 automatically, and eligible accounts are topped back up to $20 each month; a Search call costs from $0.005, roughly 4,000 searches
Official docs: "When you first sign up with a professional email address, your account is automatically credited with $20. We will top up eligible accounts back to $20 each month." Pricing: Search with searchResults output costs $0.005 per call at flash / fast / standard depth; sourcedAnswer and structured cost $0.006 per call; deep depth and the Research endpoint cost more. The homepage also says "Run 4,000 queries for free", which matches $20 divided by $0.005.
A professional email is required; the docs do not say whether free mail such as Gmail gets the credit, nor what "eligible" means or whether the monthly top-up will last, so the terms may change. An AI web-search API in the same category as Tavily, Exa and Brave.