Markdown.

Markdown is a plain-text file format that AI agent read natively. An MD file is just a markdown file, a fancy, nicely formatted text file. It's what Notion runs off.

My whole agent system is built on it. The agent's role, its jobs, its processes, its context, its Skills, all of it is just well-structured markdown folders sitting on my machine.

That's the part builders should care about. Because it's plain text, none of it is locked to one company. If Claude goes bankrupt tomorrow, you select ChatGPT instead and everything still runs off your markdown files. Same files, different brain. That portability is the whole reason I build on markdown instead of inside someone else's app, where your setup is trapped the day you want to leave.