review-swarm

review-swarm is a skill for Claude Code from alonbaron/claude-skills. It costs 149 tokens per session (1,277 once invoked), scanned A, original, MIT.

A local code-review tool that asks several specialist reviewers to examine your changes in parallel and combines their findings.

In plain words
What is it for?
Use it to review a working diff before merging or opening a pull request. It returns checked, de-duplicated findings with severity and file-and-line locations.
Why use it?
It helps catch correctness, security, performance, design, simplicity, testing, and failure-path problems that one review may miss.

Skill for Claude Code

Written for Claude Code: argument-hint in frontmatter. Also seen: reads .claude/ paths; mentions CLAUDE.md; mentions subagents.

Part of the alon-skills plugin — 6 skills shipped together

Good fit Use it to review a working diff before merging or opening a pull request. It returns checked, de-duplicated findings with severity and file-and-line locations.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/alonbaron/claude-skills/review-swarm
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.

Any agent
npx skills add alonbaron/claude-skills --skill review-swarm
Clone the repo
git clone --depth 1 https://github.com/alonbaron/claude-skills

Made for: Claude Code.

Or install alon-skills, the plugin that ships this one along with the rest of its 6 skills.

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 review-swarm

README.md
[![agentmods](https://agentmods.dev/badge/skills/alonbaron/claude-skills/review-swarm/github.svg)](https://agentmods.dev/skills/alonbaron/claude-skills/review-swarm)
Your own site
<a href="https://agentmods.dev/skills/alonbaron/claude-skills/review-swarm"><img src="https://agentmods.dev/badge/skills/alonbaron/claude-skills/review-swarm/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for review-swarm

Your own site · 80×15
<a href="https://agentmods.dev/skills/alonbaron/claude-skills/review-swarm"><img src="https://agentmods.dev/badge/skills/alonbaron/claude-skills/review-swarm.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 149 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,277 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00149 $0.01277
Opus 5 $0.00075 $0.00639
Sonnet 5 $0.00030 $0.00255
Haiku 4.5 $0.00015 $0.00128

Measured 12d ago against content hash 4ac612731e0c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

review-swarm 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 12d 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/review-swarm/SKILL.md · 103 lines

How it starts

The opening of the file, as written. The whole thing — 103 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Review Swarm

Review the working changes with a panel of specialists in parallel, then keep only the findings that survive scrutiny. Free and local (Claude subagents).

Proactive use

If the user asks to review, check, or assess changes — or you've just finished a non-trivial implementation and a PR is next — invoke this without being asked: announce in one line ("Running review-swarm on ") and proceed. Never ask permission to run the skill.

Steps

  1. Scope the diff. Default: working tree vs the default branch. stagedgit diff --staged; branch → vs merge-base with main; a path → limit to it. Read the changed hunks and enough surrounding code to judge them. Size guard: over ~40 changed files or ~2000 changed lines, don't swarm the whole thing — split by area and say which slice you reviewed, or ask which slice matters. A swarm that overruns its context reports confidently on code it never read.
  2. Fan out specialists — in parallel. Spawn the reviewers below with the Agent tool, all in one message so they run concurrently. Give each the diff plus the files it needs and its single lens. Each returns findings as: severity · file:line · what · why · suggested fix.
    • Correctness — logic errors, edge cases, null/empty, off-by-one, concurrency/races.
    • Security & trust boundaries — authz/authn (JWT), input validation at boundaries, injection, IDOR, leaked secrets.
    • Data & performance — N+1 (JPA/Hibernate, SQLAlchemy), missing indexes, unbounded queries, transaction scope, lazy-load traps.
    • Architecture & altitude — does it fit the domain model? are invariants enforced at the core? wrong layer, leaky abstraction.
    • Simplicity (ponytail lens) — over-engineering, premature abstraction, dead code, a stdlib/native one-liner that replaces the change.
    • Tests & failure paths — non-trivial logic with no test, untested failure paths, error handling that could lose data.
  3. Adversarially verify. For each non-trivial finding, spawn a verifier that tries to refute it: is it real, reproducible, not already handled elsewhere? Drop findings that don't survive. Default to dropping when uncertain.
  4. Synthesize. Dedup overlaps, then rank: Blockers → Should-fix → Nits, each with file:line and a one-line fix. Close with a short "what's solid".

Read the full file on GitHub · 103 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. 12d ago First seen · 103 lines · 149 tokens per session scan A 4ac612731e0c

Subscribe to this mod's changes

review-swarm is a skill published in the GitHub repository alonbaron/claude-skills (13 stars, last pushed 1mo ago), licensed MIT. It adds 149 tokens to every session and 1,277 once invoked, about $0.0007 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.

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