A commit tells you what changed. It never tells you what was tried at 2am and abandoned, which constraint made the obvious approach impossible, or why the retry has a comment that says "do not touch".
That knowledge lives in agent sessions, and agent sessions are the least durable thing in modern engineering. They sit in a JSONL file under a mangled path, or inside a SQLite blob, until someone clears their cache. We treat them like terminal scrollback. They are closer to lab notebooks.
Motif starts from the opposite assumption: the session is the artifact worth keeping. Everything else in the product follows from that one line.
The asymmetry is what makes this expensive. Writing the code took an hour; working out which code to write took a day, and only the hour survives. A new teammate reads the hour and re-lives the day. So does an agent, every single session, because it starts from a repository that records only conclusions.
You can see the cost in how people work around it. The CLAUDE.md that grows until nobody maintains it. The Slack thread someone links to for the third time. The comment that says do not change this without saying why, because the why was in a session that closed months ago. Each of those is a hand-rolled, lossy attempt to keep reasoning that the tools threw away.
Treating the session as the artifact changes what the software has to do. It has to collect without being asked, because nobody remembers to save. It has to survive the tool that produced it, because tools get swapped. And it has to be queryable by the thing that will need it most, which is not a person browsing a dashboard but an agent about to guess.