loop-verifier

loop-verifier is a skill for Claude Code, Codex from haidrrrry/loop-engineering-skills. It costs 121 tokens per session (1,122 once invoked), scanned A, original, MIT.

A checking guide for coding tasks that defines the checks before implementation and runs them before work is called finished.

In plain words
What is it for?
Use it to turn project rules and task requirements into a check list, test edge cases, and confirm whether a coding task is actually done.
Why use it?
It reduces the risk of accepting code because the agent's own checks repeat the same mistakes. It also requires real test, build, and lint results where available.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/haidrrrry/loop-engineering-skills/loop-verifier
Any agent
npx skills add haidrrrry/loop-engineering-skills --skill loop-verifier
Clone the repo
git clone --depth 1 https://github.com/haidrrrry/loop-engineering-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for loop-verifier

README.md
[![agentmods](https://agentmods.dev/badge/skills/haidrrrry/loop-engineering-skills/loop-verifier.svg)](https://agentmods.dev/skills/haidrrrry/loop-engineering-skills/loop-verifier)
Your own site
<a href="https://agentmods.dev/skills/haidrrrry/loop-engineering-skills/loop-verifier"><img src="https://agentmods.dev/badge/skills/haidrrrry/loop-engineering-skills/loop-verifier.svg" alt="Measured on agentmods" height="20"></a>
Per session 121 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,122 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00121 $0.01122
Opus 5 $0.00060 $0.00561
Sonnet 5 $0.00024 $0.00224
Haiku 4.5 $0.00012 $0.00112

Measured 5d ago against content hash 67c58b57eeb5, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

loop-verifier scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/loop-verifier/SKILL.md · 104 lines

How it starts

The opening of the file, as written. The whole thing — 104 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Loop Verifier

The checker half of the maker/checker split. Turns "the agent says it's done" into "the gates say it's done." Built on one anti-cheating rule from the research: checks must be derived from the TASK, before or independently of the implementation — an agent that writes its checks after coding tends to write checks that mirror its own mistakes.

The protocol

1. Before implementing: write the checks

From the task description and .loop/GATES.md, produce the concrete check list for this task:

  • Which universal gates apply (they all do) and what they mean here
  • Which task-type gates apply (code / bug fix / refactor / docs / dependency)
  • The project-specific commands (build, test, lint) that must exit clean
  • 3–5 task-specific checks: edge cases, invariants, a worked example with a known expected result

Write this list down BEFORE writing any implementation. This ordering is the whole defense against self-confirming verification.

2. After implementing: run the gates

  • Execute every runnable check for real (tests, build, lint). Paste actual output, not a summary of expected output.
  • For non-runnable checks, walk each one explicitly: state the check, quote the evidence from the work, mark pass/fail.
  • The Decompose audit is always included: every requirement in the task gets a quote from the output that satisfies it. No quote = gap = fail.

3. Verdict rules

  • PASS requires: all applicable gates green, all checks walked, no check skipped silently.
  • FAIL must name which gate failed and why — that line feeds the retry.
  • A check you couldn't run (missing env, no test framework) is reported as UNRUN, and UNRUN on a required gate means the verdict is FAIL, not PASS. Unverifiable is not verified.
  • Never soften a verdict because effort was high. The verdict describes the work, not the attempt.

4. Escalation triggers (hand to the human immediately)

  • Any action on the GATES.md "Never" list would be required to proceed
  • The same gate has failed 3 times for the same root cause
  • The task requires changing the gates themselves
  • Trust level is L1 and the fix requires applying changes

Read the full file on GitHub · 104 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago First seen · 104 lines · 121 tokens per session scan A 67c58b57eeb5

Subscribe to this mod's changes

loop-verifier is a skill published in the GitHub repository haidrrrry/loop-engineering-skills (2 stars, last pushed 2mo ago), licensed MIT. It adds 121 tokens to every session and 1,122 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.