Autonomous AI agents are no longer theoretical. In Q1 2026, 68% of new DeFi protocols shipped with at least one AI agent. Protocols like x402 have processed $600M+ in machine-to-machine payments. Miners are pivoting GPU capacity from Bitcoin to AI workloads. This piece maps the five layers of the AI-crypto stack that every builder and investor should understand right now—from decentralized compute to agentic payments to the security gaps nobody has solved yet.