An AI SDR is software that performs the top-of-funnel work a sales development rep does: find accounts, research them, write the first message, send it, follow up, handle the reply, and book the meeting. Some products do all seven steps. Most do three or four well and the rest badly. The category arrived promising a headcount replacement and spent two years being corrected by customers. The useful reading in 2026 is neither "it works" nor "it's a scam." The technology is real