Everyone's talking about loop engineering. Here's what it actually is. It's not the ReAct loop your agent already runs (reason, act, observe, repeat). That ships built in. You don't engineer that. Loop engineering is everything wrapped around the agent: what kicks it off, what feeds it work, what checks the output, what decides to run again or stop. The agent owns the inner loop. You design the outer one. Core idea: the prompt is no longer the unit of work, the loop is. Give it a goal and a success condition, and it keeps taking turns until that condition holds. Codex and Claude Code already ship this natively as /goal. It also sidesteps context rot. Instead of one long session piling up dead ends, each iteration starts fresh, reads state, does one unit of work, exits. The catch is tokens. Loops burn them on every retry and re-read, so cap it before trusting it to run overnight. Is anyone here already building with loops instead of turn by turn prompting?