Fyxer uses OpenAI models to draft emails Fyxer's executive-assistant agent uses OpenAI models combined with fine-tuning, persistent memory, and a real user-feedback loop to sort inboxes and draft email replies in each user's own voice, according to OpenAI. The company's production lesson is that trust for executive-assistant agents comes less from a generic model upgrade and more from a tight personalization loop that captures preferences, remembers context, and continuously corrects behavior from user feedback. The write-up argues static prompt engineering is insufficient for high-agency tasks, requiring a stateful architecture that adapts to individual user behavior. OpenAI https://openai.com/index/fyxer Fyxer uses OpenAI models to draft emails Which summary reads better? Pick one — models revealed after.Both summaries are AI-generated. Automating high-trust write actions like email drafting in a user's specific voice requires combining LLM fine-tuning with persistent memory and an active human-feedback loop. For engineers shipping production agents, this proves that static prompt engineering is insufficient for high-agency tasks, necessitating a stateful architecture that continuously adapts to individual user behavior. Implementing this triple-tier stack of fine-tuning, memory, and feedback is the emerging blueprint for moving agents from read-only assistants to trusted, autonomous executors. Fyxer’s assistant combines OpenAI models with fine-tuning, memory, and real user feedback to sort inboxes and draft replies in each user’s own voice. The production lesson is that trust for executive-assistant agents comes less from a generic model upgrade and more from a tight personalization loop that captures preferences, remembers context, and continuously corrects behavior from user feedback.