After 15 years of software eating the world, AI agents are now positioned to eat SaaS. Engineers increasingly build custom solutions in minutes rather than buying SaaS tools, and companies question renewal costs as agents make internal development feasible. This threatens SaaS economics built on growth and retention, particularly for simple CRUD tools and dashboards. However, mission-critical systems requiring high uptime, compliance, network effects, or proprietary data remain protected. The shift will likely split the market between technically capable organizations building internally versus those still relying on SaaS vendors.