Claude Code just dropped "Getting Started with Loops" This is their first official document about Loop Engineering. Spoiler: prompt engineering didn't survive. Here's the full guide in one post: 1. Turn-based Every prompt you send already runs as a loop: Claude gathers context, takes action, checks its own work, and repeats until it decides the task is done or realizes it needs your input. 2. Goal-based You define what "done" looks like with /goal, and Claude keeps iterating toward it. Every time it tries to stop, a separate evaluator model checks your condition - if it's not met, Claude gets sent back to work until the goal is reached or the turn limit hits. 3. Time-based This is the /loop command: нou set an interval and a prompt fires on schedule. For example, every 5 minutes Claude checks your PR, addresses review comments, and fixes failing CI. 4. Proactive Here you set up an event once, and the loop triggers itself whenever that event happens - with zero human input. Anthropic also shared optimization advice - and this part matters most: - Loop quality depends on system quality. - Tokens are the real cost None of this is magic. It's the same familiar parts - /goal, /loop, Skills, Hooks - composed into systems that run without you. I built exactly that kind of system in my article: Loop that wakes up at 6 AM, finds work on its own, reviews itself, and leaves ready PRs for you. Step by step, from SKILL(.)md to cron trigger: