The Agent-to-Agent Continuity Gap Nobody Is Talking About

TL;DR: Most AI agent memory discussions still assume one agent talking to itself across sessions. But real coding workflows already involve Claude, Codex, Cursor, and Gemini touching the same repo in the same week. The hard problem is not "how does an agent remember." It is "how do multiple agents stay coordinated on the same project without stepping on each other." That problem does not live inside any one agent. It lives in the repo. I wrote a post last week arguing that AI coding agent memory belongs in the repository, not the chat window. Checkpoints, not transcripts.