Castline is an AI sales agent that researches prospects, writes personalized cold emails, and manages full sequences — 24/7, without human intervention.
Scans LinkedIn, company news, and job postings to identify your ideal targets. Builds enriched prospect lists automatically — no manual research.
Writes every cold email from scratch based on real research, not merge tags. Each message is unique — your prospects can't tell it's automated.
Manages multi-step email sequences with A/B testing, optimal send-time optimization, and intelligent follow-up triggers based on engagement.
Learns from opens, clicks, and replies. Continuously improves targeting and message quality — your best-performing SDR gets smarter every week.
For years, cold outreach was a volume game. More emails, more chances. But LLMs changed the rules. Now the team with the best AI and the best data wins — regardless of headcount.
Castline gives every B2B founder a full outbound team: researcher, writer, and SDR — all in one autonomous agent. At a fraction of the cost.
Stop buying tools. Start hiring employees. Castline works while you sleep, learns from every campaign, and builds pipeline without adding headcount.