I measured what it costs an AI agent to read my Obsidian vault — a derived index made it ~150x cheapertranslating…

I keep a plain Obsidian vault — about 1.4 MB of markdown across notes, projects and an inbox — and I let coding agents (the Claude Code / Cursor kind) work inside it: searching, summarizing, drafting. The first thing I measured changed how I set all of this up: an agent that…