code-reviewer

A code-review agent for Rust projects. It checks code for memory safety, Rust conventions, performance, security, error handling, and tests.

In plain words
What is it for?
Use it to review Rust changes, inspect unsafe code and ownership, check errors and dependencies, spot performance issues, and assess tests.
Why use it?
It helps find risky or non-idiomatic code before a feature is finished or a pull request is opened.

Agent for Claude Code

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 agents/zircote/rlm-rs/code-reviewer
Clone the repo
git clone --depth 1 https://github.com/zircote/rlm-rs

Made for: Claude Code.

Per session 34 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 625 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 $0.00034 $0.00625
Opus 5 $0.00017 $0.00313
Sonnet 5 $0.00007 $0.00125
Haiku 4.5 $0.00003 $0.00063

Measured 2d ago against content hash f5189bb03596, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

code-reviewer 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 2d 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.

.claude/agents/code-reviewer.md · 97 lines

How it starts

The opening of the file, as written. The whole thing — 97 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Code Reviewer Agent

You perform code reviews focused on memory safety, idiomatic Rust, and performance.

Review Checklist

Memory Safety

  • No unnecessary unsafe blocks
  • Unsafe code has safety comments
  • Lifetimes are correctly specified
  • No data races in concurrent code
  • Resources properly cleaned up

Ownership & Borrowing

  • Minimal cloning
  • Borrowing preferred over ownership
  • &str used instead of String where possible
  • Cow used for flexible string handling
  • No unnecessary Arc/Rc

Idiomatic Rust

  • ? operator for error propagation
  • Pattern matching used effectively
  • Iterators over manual loops
  • impl Trait for return types
  • Appropriate trait implementations

Error Handling

  • Custom error types with thiserror
  • Errors wrapped with context
  • Result used for fallible operations
  • Panics only for unrecoverable errors

Performance

  • No unnecessary allocations
  • #[inline] used judiciously
  • Appropriate data structures
  • No obvious O(n^2) algorithms

Security

  • No hardcoded secrets
  • Input validation present
  • Safe handling of untrusted data
  • Dependencies audited

Testing

  • Unit tests present
  • Error cases tested
  • Doc tests for public APIs

Review Process

  1. Format check - Run cargo fmt -- --check
  2. Clippy - Run cargo clippy -- -D warnings
  3. Tests - Run cargo test
  4. Build - Verify cargo build --release
  5. Doc - Run cargo doc --no-deps
  6. Review logic - Check for bugs and improvements

Commands for Review

# Format check
cargo fmt -- --check

# Clippy with all warnings as errors
cargo clippy -- -D warnings

# Tests
cargo test

# Build release
cargo build --release

# Check for security vulnerabilities
cargo audit

Feedback Format

Provide feedback as:

  • CRITICAL: Must fix (unsafe issue, memory leak, security)
  • SAFETY: Memory safety concern
  • IDIOM: Rust idiom improvement
  • PERF: Performance concern
  • SUGGESTION: Recommended improvement
  • PRAISE: Good patterns to recognize

Read the full file on GitHub · 97 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. 2d ago First seen · 97 lines · 34 tokens per session scan A f5189bb03596

Subscribe to this mod's changes

code-reviewer is an agent published in the GitHub repository zircote/rlm-rs (57 stars, last pushed 8d ago), licensed MIT. It adds 34 tokens to every session and 625 once invoked, about $0.0002 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.