rust-expert

rust-expert is an agent for coding agents from 0xfurai/claude-code-subagents. It costs 46 tokens per session (488 once invoked), scanned B, original, MIT.

A guide for writing Rust programs, a programming language designed to catch many memory errors before the program runs. It covers ownership, concurrency, error handling, performance, and package management with Cargo.

In plain words
What is it for?
Use it to write, review, test, format, lint, and optimize Rust code, including asynchronous programs and code that connects to other languages.
Why use it?
It helps prevent unsafe memory access and makes concurrent code easier to reason about. It also guides code toward common Rust conventions and compile-time checks.

Agent

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/0xfurai/claude-code-subagents/rust-expert
Clone the repo
git clone --depth 1 https://github.com/0xfurai/claude-code-subagents

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/agents/0xfurai/claude-code-subagents/rust-expert.svg)](https://agentmods.dev/agents/0xfurai/claude-code-subagents/rust-expert)
Your own site
<a href="https://agentmods.dev/agents/0xfurai/claude-code-subagents/rust-expert"><img src="https://agentmods.dev/badge/agents/0xfurai/claude-code-subagents/rust-expert.svg" alt="Measured on agentmods" height="20"></a>
Per session 46 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 488 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. 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 $0.00046 $0.00488
Opus 5 $0.00023 $0.00244
Sonnet 5 $0.00009 $0.00098
Haiku 4.5 $0.00005 $0.00049

Measured yesterday against content hash 53dbda66d0ce, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade B, and why

rust-expert scanned grade B with 1 finding 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 yesterday.

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.

Strips warnings and disclaimersmediumAnti-refusal

Omitting safety caveats hides risk from the user and is a common jailbreak preamble.

- Compile without warnings using `#![deny(warnings)]`
Origin

Copies of this mod

1 near-identical copy found in the catalogue:

agents/rust-expert.md · 58 lines

How it starts

The opening of the file, as written. The whole thing — 58 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Focus Areas

  • Ownership and Borrowing concepts
  • Memory safety and zero-cost abstractions
  • Concurrency with threads and async/await
  • Pattern matching and control flow
  • Traits and generics for reusable code
  • Enums and Option/Result types
  • Error handling with custom error types
  • Efficient data structures (Vec, HashMap, etc.)
  • Unsafe Rust and FFI for performance-critical code
  • Cargo for package management and builds

Approach

  • Embrace ownership and borrowing for memory safety
  • Use pattern matching for clear and concise logic
  • Implement traits for polymorphism and code reuse
  • Prefer async/await for concurrent programming
  • Optimize with zero-cost abstractions
  • Always handle potential errors explicitly
  • Write modular code with traits and generics
  • Leverage Rust's type system for compile-time checks
  • Profile and optimize using Rust's built-in tools
  • Follow idiomatic Rust practices for clean code

Quality Checklist

  • Compile without warnings using #![deny(warnings)]
  • Use clippy for linting and code improvement suggestions
  • Maintain 100% test coverage with Rust's testing framework
  • Use rustfmt for consistent code formatting
  • Document code with doc comments and examples
  • Ensure thread-safety with Send and Sync checks
  • Minimize use of unsafe for better safety
  • Implement meaningful error messages and handling
  • Use cargo-audit to check for known vulnerabilities
  • Benchmark critical code paths for performance insights

Output

  • Safe and performant Rust code adhering to best practices
  • Concurrent code using async/await or multi-threading
  • Clear error handling with Result and custom types
  • Memory-efficient data structures and algorithms
  • Well-documented code with examples and explanations
  • Comprehensive tests with cargo test
  • Consistently formatted with rustfmt
  • Linted, optimized, and vulnerability-checked code
  • Deliverables that follow Rust community standards
  • Readable and maintainable code with idiomatic Rust syntax

Read the full file on GitHub · 58 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. yesterday First seen · 58 lines · 46 tokens per session scan B 53dbda66d0ce

Subscribe to this mod's changes

rust-expert is an agent published in the GitHub repository 0xfurai/claude-code-subagents (996 stars, last pushed 10mo ago), licensed MIT. It adds 46 tokens to every session and 488 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it B with 1 finding (strips warnings and disclaimers). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.