Loop Builder

🔁 loop-builder

A Claude Code skill that builds the **harness** for a long task *before* running it — so you design the loop once and only **verify the output**, instead of babysitting every step.

Stop prompting your agent one step at a time. Define a **goal** and a **verifiable done-condition**; `loop-builder` scaffolds a file-based loop on disk (vision, specs, plan, prompts, engine), runs a planning pass, asks for **one** approval, then loops autonomously until the work clears your requirements — and hands you back a diff plus the proof it passed.

This is **loop engineering**: the leverage moves from the quality of a single prompt to the design of the system that prompts, runs, and *verifies* the agent.

Works on **a single machine**. No special infrastructure, no second computer. The only dependency for unattended runs is the `claude` CLI and a git repo.

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Why

For the last couple of years we prompted agents one task at a time, driving every step by hand. The shift: you build a loop that handles discovery → planning → work → checking → iterating until the goal is met. One human role remains — **stay the engineer**: you design the boundaries and verify the result. You don't sit *in* the loop, you sit *on* it.

The hard-won lesson from people running these at scale: an unbounded "open" loop with a loose standard becomes a slop machine. So `loop-builder` builds a **closed** loop by default — a bounded path with an eval-gate at each step that runs on a normal budget and gets better every pass.

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How it works

INTERVIEW (4-5 questions)
      │
SCAFFOLD loops//  +  PLANNING  →  IMPLEMENTATION_PLAN.md
      │
   ┌──┴── GATE 1: you approve VISION + PLAN     ← the "design"
   │
BUILDING loop (autonomous: maker → verifier → commit, one task per pass)
      │
   ┌──┴── GATE 2: you verify the output (diff + eval results)   ← the "verify"

Only two moments need you: **approve the plan**, then **verify the output**. Everything in between is