agent architecture

I structure my chats in Claude as departments for my startup, VYNS. I have a few chats that persist for personal use, and most other one-off chats I end up deleting after I gather the intel I need. But for VYNS, I keep a few persistent chats that are critical for my work as a solo founder. The most important of these are my Build logs, sequential chats where the previous one summarizes all key findings and stages as a prompt for the next to open and resume our work once the current chat reaches capacity. I also keep dedicated chats for Marketing, Philosophical, Competitor Research, Partnership Opps, and Local Resources. What I eventually want to build is an agent for each chat and an Executive Assistant agent that reads across and internally interacts with all of these based on my activity throughout the day, synthesizes findings, and reports back with a daily briefing highlighting my top priorities across the VYNS build and my personal brand. The limitation: no major LLM that I know of exposes read access to existing chat history. The threads are locked inside the web interface. This means I have to manually copy and paste references between chats and to my EA agent, as I largely do now. This isn't a small gap. It's a missing architectural primitive that would unlock an entirely new category of AI-assisted organizational design.