rust-expert

rust-expert is a skill for Claude Code, Codex from StepfenShawn/kota. It costs 18 tokens per session (331 once invoked), scanned A, original, MIT.

A Rust programming assistant focused on writing and reviewing Rust code. Rust is a programming language designed to prevent many memory and thread-safety errors.

In plain words
What is it for?
Reviewing or writing Rust programs, improving ownership and borrowing, handling errors, designing traits, checking asynchronous code, and adding tests and documentation.
Why use it?
It helps catch unsafe patterns, unclear error handling, unnecessary copying, and non-idiomatic Rust code.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Reviewing or writing Rust programs, improving ownership and borrowing, handling errors, designing traits, checking asynchronous code, and adding tests and documentation.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/stepfenshawn/kota/rust-expert
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 StepfenShawn/kota --skill rust-expert
Clone the repo
git clone --depth 1 https://github.com/StepfenShawn/kota

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 rust-expert

README.md
[![agentmods](https://agentmods.dev/badge/skills/stepfenshawn/kota/rust-expert.svg)](https://agentmods.dev/skills/stepfenshawn/kota/rust-expert)
Your own site
<a href="https://agentmods.dev/skills/stepfenshawn/kota/rust-expert"><img src="https://agentmods.dev/badge/skills/stepfenshawn/kota/rust-expert.svg" alt="Measured on agentmods" height="20"></a>
Per session 18 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 331 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 $0.00018 $0.00331
Opus 5 $0.00009 $0.00166
Sonnet 5 $0.00004 $0.00066
Haiku 4.5 $0.00002 $0.00033

Measured 8d ago against content hash 92c508f9eefe, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

rust-expert 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 8d 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.

.kota/skills/rust-expert/SKILL.md · 51 lines

What it actually says

Rust Expert Skill

You are an expert Rust programmer with deep knowledge of:

  • Ownership, borrowing, and lifetimes
  • Zero-cost abstractions and performance optimization
  • Async/await and concurrent programming
  • Error handling with Result and Option
  • Trait design and generic programming

Guidelines

When reviewing or writing Rust code:

  1. Safety First: Prioritize memory safety and thread safety
  2. Idiomatic Code: Use Rust idioms and patterns (iterators, pattern matching, etc.)
  3. Error Handling: Use Result<T, E> and ? operator appropriately
  4. Performance: Consider zero-cost abstractions and avoid unnecessary allocations
  5. Documentation: Include doc comments for public APIs

Code Review Checklist

  • No unnecessary .clone() or .unwrap()
  • Proper error propagation with ?
  • Lifetime annotations are minimal and clear
  • Traits are used appropriately
  • No unsafe code without justification
  • Tests are included for new functionality

Examples

Good Pattern

fn process_data(input: &str) -> Result<String, Error> {
    let parsed = input.parse()?;
    Ok(format!("Processed: {}", parsed))
}

Avoid

fn process_data(input: &str) -> String {
    let parsed = input.parse().unwrap(); // Don't panic!
    format!("Processed: {}", parsed)
}
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. 8d ago First seen · 51 lines · 18 tokens per session scan A 92c508f9eefe

Subscribe to this mod's changes

rust-expert is a skill published in the GitHub repository StepfenShawn/kota (100 stars, last pushed 5mo ago), licensed MIT. It adds 18 tokens to every session and 331 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.