loom-code-review

loom-code-review is a skill for Claude Code, Codex from cosmix/loom. It costs 22 tokens per session (2,033 once invoked), scanned A, original, MIT.

A code-review guide for checking proposed changes for bugs, security problems, speed issues, and hard-to-maintain code. It also helps produce prioritized feedback on pull requests and other changes.

In plain words
What is it for?
Use it to review pull requests, check changes before merging, assess designs, and give clear feedback on architecture and implementation choices.
Why use it?
It helps reviewers focus first on problems that could harm users or make a release unsafe, while separating normal review from an attacker-focused security audit.

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/cosmix/loom/loom-code-review
Any agent
npx skills add cosmix/loom --skill loom-code-review
Clone the repo
git clone --depth 1 https://github.com/cosmix/loom

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 loom-code-review

README.md
[![agentmods](https://agentmods.dev/badge/skills/cosmix/loom/loom-code-review.svg)](https://agentmods.dev/skills/cosmix/loom/loom-code-review)
Your own site
<a href="https://agentmods.dev/skills/cosmix/loom/loom-code-review"><img src="https://agentmods.dev/badge/skills/cosmix/loom/loom-code-review.svg" alt="Measured on agentmods" height="20"></a>
Per session 22 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,033 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 $0.00022 $0.02033
Opus 5 $0.00011 $0.01017
Sonnet 5 $0.00004 $0.00407
Haiku 4.5 $0.00002 $0.00203

Measured today against content hash e88493bd6892, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

loom-code-review 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 today.

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/loom-code-review/SKILL.md · 161 lines

How it starts

The opening of the file, as written. The whole thing — 161 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Code Review

Overview

Review a change for correctness, security, performance, and maintainability, then produce prioritized, actionable feedback. Optimize signal: gate on what breaks users; comment (don't gate) on the rest.

Review vs. adversarial security audit

Different jobs — don't conflate:

  • Code review (this skill): holistic, author-empathetic. Reviews the diff and its blast radius against stated intent across four lenses. Assumes good faith; catches the bugs a careful peer catches.
  • Security audit (Skill(skill="loom-skills", args="loom-security-audit"), Skill(skill="loom-skills", args="loom-threat-model")): attacker mindset, threat model, whole-attack-surface. Assumes hostile input everywhere.

For auth, crypto, payments, deserialization, or anything touching a trust boundary: do the code review AND trigger a security audit. A passing code review is not a security sign-off.

Severity taxonomy

Label every comment. BLOCKER, SILENT_FAILURE, and CRITICAL gate the merge.

Severity Gate? Meaning
BLOCKER Security hole, data loss, crash, corruption. Merge is unsafe.
SILENT_FAILURE Exit 0 but the operation actually failed (sandbox-blocked download, partial fetch, stale cache, swallowed error). Always investigate before merge.
CRITICAL Logic error / real bug that will bite in normal use.
MAJOR Maintainability, tech debt, missing test for a real path. Fix soon.
MINOR / nit Style, naming, micro-optimization. Prefix with nit: so the author can skip it.

Approve-with-comments discipline: if nothing is BLOCKER/SILENT_FAILURE/CRITICAL, approve and leave the MAJOR/MINOR notes as non-blocking. Don't hold a PR hostage over nits or personal style. Blocking on taste is the top reviewer anti-pattern — it trains authors to ignore you.

Read the full file on GitHub · 161 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. today Changed · -20 tokens per session e88493bd6892
  2. 4d ago First seen · 161 lines · 42 tokens per session scan A 580d4857b1fc

Subscribe to this mod's changes

loom-code-review is a skill published in the GitHub repository cosmix/loom (54 stars, last pushed today), licensed MIT. It adds 22 tokens to every session and 2,033 once invoked, about $0.0001 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 2026-08-30.