How much equity should I give my first engineer? I will not promote

I have started an AI company in Spain and I sell AI agents to large companies. We have a suite of vertical AI agents, each taking care of a part of our customer's customer journey. I will not go more in detail to keep us as anonymous as possible. I have already shipped the first agent which is in production generating six figure ARR for us. I have signed a contract for a second agent in the suite which doubles our ARR and we are in the final stages of signing a new deal which will give us 3.5x growth in a m