Diopter protects teams from AI social engineering on video and voice calls, so the person answering does not have to be the last line of defense. Synthetic video and cloned audio have made it harder to trust the calls where teams approve payments, grant access, verify claims and make hiring decisions. A finance employee joins a video call with a CFO who isn't real and authorizes fifteen transfers. A bank manager hears a voice he recognizes and moves $35M. A hiring loop passes a candidate who is a synthetic persona. Fraud is rarely detectable from a single frame or voice sample. It unfolds across a conversation, and the arc is the unit of analysis. Diopter scores that arc live: it confirms who is on the call and validates payment instructions, detects synthetic video and cloned voices continuously rather than from one frame, tracks the authority, urgency, isolation, escalation and ask pattern attackers use, and flags requests that bypass your approval controls. Four signals become one verdict your team can act on. Diopter is built for enterprise security and fraud teams, private equity funds, and large enterprise fraud and IT. Detection runs on the endpoint by default, so only verdicts and scores leave the device, and it rolls out through the MDM your IT team already runs. SOC 2 Type II in progress.