Callbook AI

Callbook AI is a Y Combinator (S26) startup building AI voice agents that make and take business phone calls in English, Spanish, and Portuguese. Founded by Colombians Diego Avellaneda and Daniel Martinez, it began as a plug-and-play AI phone system for Zoho CRM and has sharpened its focus on automated debt collections and portfolio management across Latin America, handling calls, WhatsApp, SMS, and email from a single platform.