Andreessen Horowitz Backs Runta With $20M Seed to Keep AI Agents in Check

Andreessen Horowitz has led a $20 million seed round in Runta, a startup building sandboxes and runtime guardrails designed to keep increasingly autonomous AI agents under control. The financing values the company at more than $100 million and was led by a16z's Martin Casado, according to the deal terms disclosed around its July 16, 2026 launch.