review-rust

review-rust is a skill for Claude Code from existential-birds/beagle. It costs 47 tokens per session (4,566 once invoked), scanned A, original, Apache-2.0.

A broad Rust code-review guide that checks a project before a push or pull request. It can divide the review by detected technology areas and requires an explicit file scope, compiler or linter checks, and recorded evidence.

In plain words
What is it for?
Use it for a pre-commit or pre-pull-request review of Rust files across a crate or workspace.
Why use it?
It helps prevent reviews from inventing findings, missing compiler or Clippy results, or reporting serious issues without first checking the relevant files and project state.

Skill for Claude Code

Written for Claude Code: disable-model-invocation in frontmatter. Also seen: mentions subagents.

Part of the beagle-rust plugin — 11 skills shipped together

Good fit Use it for a pre-commit or pre-pull-request review of Rust files across a crate or workspace.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/existential-birds/beagle/review-rust
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 existential-birds/beagle --skill review-rust
Clone the repo
git clone --depth 1 https://github.com/existential-birds/beagle

Made for: Claude Code.

Or install beagle-rust, the plugin that ships this one along with the rest of its 11 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-rust

README.md
[![agentmods](https://agentmods.dev/badge/skills/existential-birds/beagle/review-rust/github.svg)](https://agentmods.dev/skills/existential-birds/beagle/review-rust)
Your own site
<a href="https://agentmods.dev/skills/existential-birds/beagle/review-rust"><img src="https://agentmods.dev/badge/skills/existential-birds/beagle/review-rust/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-rust

Your own site · 80×15
<a href="https://agentmods.dev/skills/existential-birds/beagle/review-rust"><img src="https://agentmods.dev/badge/skills/existential-birds/beagle/review-rust.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 47 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,566 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 $0.00047 $0.04566
Opus 5.5 $0.00019 $0.01826
Sonnet 5.5 $0.00009 $0.00913
Haiku 4.5 $0.00005 $0.00457

Measured 1mo ago against content hash 66069d641075, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

review-rust 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 1mo 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.

plugins/beagle-rust/skills/review-rust/SKILL.md · 327 lines

How it starts

The opening of the file, as written. The whole thing — 327 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Rust Code Review

Arguments

  • --parallel: If the agent supports subagents, dispatch one per technology area in parallel; otherwise run sequentially with identical output.
  • Path: Target directory (default: current working directory)

Hard gates

Complete in order before writing Issues in the output (empty scope is allowed; fabricated findings are not).

  1. Scope gate: You have an explicit list of .rs paths under review (from Step 1 or the user-provided path). Pass: List printed or "No Rust files in scope" — then stop with no Issues.
  2. Compiler/linter gate: Step 3 commands were run from the crate or workspace root (Cargo.toml present); if they cannot run, one line states why (e.g. missing toolchain, no Cargo.toml, sandbox). Pass: You do not report a problem already shown as an error/warning in Step 3 output, and you do not duplicate compiler or clippy diagnostics the author must fix first.
  3. Protocol gate: the review-verification-protocol skill is loaded before Step 7. Pass: Every Critical/Major finding satisfies Step 8 (and the protocol); if there are zero findings, say "Protocol applied; no issues" in the Review Summary.
  4. Evidence gate (Critical/Major): For each Critical or Major item, you re-read the file at FILE:LINE with full surrounding context (not only the diff hunk). Pass: The Issue description matches observable code at that location.

Step 1: Identify Changed Files

git diff --name-only $(git merge-base HEAD main)..HEAD | grep -E '\.rs$'

Step 2: Check Rust Edition and MSRV

# Check Cargo.toml for edition and rust-version
grep -E 'edition|rust-version' Cargo.toml

# Check workspace members if workspace
grep -A 20 '\[workspace\]' Cargo.toml

Edition 2024 awareness (requires MSRV 1.85+):

If edition = "2024" is detected, the following behavioral changes apply throughout the review:

  • unsafe_op_in_unsafe_fn is deny by default — unsafe operations inside unsafe fn MUST use explicit unsafe {} blocks
  • extern "C" {} blocks must be unsafe extern "C" {}
  • #[no_mangle] and #[export_name] must be #[unsafe(no_mangle)] and #[unsafe(export_name)]
  • -> impl Trait captures ALL in-scope lifetimes by default (RPIT lifetime capture change); use + use<'a> for precise capture
  • gen is a reserved keyword — code using it as an identifier must use r#gen
  • ! (never type) falls back to ! instead of () — may change behavior of inferred types
  • Temporaries in if let conditions and tail expressions are dropped earlier than in edition 2021
  • Box<[T]> now implements IntoIterator

Read the full file on GitHub · 327 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. 1mo ago First seen · 327 lines · 47 tokens per session scan A 66069d641075

Subscribe to this mod's changes

review-rust is a skill published in the GitHub repository existential-birds/beagle (82 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 47 tokens to every session and 4,566 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-09-16.

Related

Other skills, from other repositories

no-bare-casts

Writing as in TypeScript or TSX production code, modifying a file that contains a bare as cast, silencing a type error with a cast, encountering as unknown as, or reviewing a cast site.

prisma/orm · 52 tokens

splitting-oversized-modules

Split an oversized Python module (a thousand-plus-line logic.py, models.py, api.py, or its test file) into a package of one module per concern, mechanically and provably without changing behavior. Use on a request to split / break up / decompose a god module or move functions out of one, once a human has agreed to…

PostHog/posthog-foss · 197 tokens

splitting-oversized-modules

Split an oversized Python module (a thousand-plus-line logic.py, models.py, api.py, or its test file) into a package of one module per concern, mechanically and provably without changing behavior. Use on a request to split / break up / decompose a god module or move functions out of one, once a human has agreed to…

PostHog/posthog · 197 tokens

r-tidyverse-style

Use when the user asks to review or clean up R code for tidyverse style, standardize formatting or names, remove redundant comments or wrappers, or make a behavior-preserving style pass. Also use when writing substantial new R package code if the user requests tidyverse style or the package already follows it. Not for…

posit-dev/skills · 83 tokens

solid-principles

SOLID principles checklist with Java examples. Use when a class has too many responsibilities, an abstraction leaks, or a dependency points the wrong way, and when the user asks about Single Responsibility, Open/Closed, Liskov, Interface Segregation or Dependency Inversion. For naming, duplication and method length…

decebals/claude-code-java · 73 tokens

ring:auditing-dependency-security

Auditing a dependency for supply-chain risk before install (pip/npm/go/cargo): checks typosquatting, maintainer/age risk, vulnerability DBs (OSV, GHSA, Socket), and lockfile hash pinning, then emits a risk score and approve/conditional/escalate/block decision. Use when adding or updating a dependency, reviewing a…

LerianStudio/ring · 102 tokens