My coding agents keep a record of what they decided and why, not just what they built A developer built a system that forces AI coding agents to log their reasoning and decisions into an Obsidian vault, synced across machines and a phone. The setup uses three hooks that inject context, nudge the agent, and block session closure until a devlog entry is written, preserving the 'why' behind code changes. A session with a coding agent ends and whatever it figured out along the way goes with it. The code survives, since it's on disk. The reasoning behind the code doesn't: why this table got a composite index instead of two separate ones, why the retry logic gave up after three attempts instead of five, which approach got tried first and thrown out. Open a new session next week on the same project and the agent starts from the code alone, with no memory of any of that. Claude Code has a memory system for this, and it's genuinely good at what it does. Cursor has nothing like it. I run the two on different machines for different kinds of work, Claude Code where I vibecode, Cursor on a separate box for the work I want to sit with, so it was never a question of getting one tool's session context into the other's. What I wanted was a record of the reasoning that outlives any single machine: an Obsidian vault, synced with the self-hosted obsidian-livesync plugin, that both machines write into and that also lands on my phone for a quick read when I'm nowhere near either one.