Rust Engineer

What it does

When your agent uses it

• Building Rust applications
• Solving ownership
• Borrowing issues
• Designing trait-based APIs

Example prompts

• “/rust-engineer”

Workflow steps

5 steps, taken from the first numbered list in SKILL.md.

1. 1Analyze ownership — Design lifetime relationships and borrowing patterns; annotate lifetimes explicitly where inference is insufficient
2. 2Design traits — Create trait hierarchies with generics and associated types
3. 3Implement safely — Write idiomatic Rust with minimal unsafe code; document every unsafe block with its safety invariants
4. 4Handle errors — Use Result/Option with ? operator and custom error types via thiserror
5. 5Validate — Run cargo clippy --all-targets --all-features, cargo fmt --check, and cargo test; fix all warnings before finalising

What it can do on your machine

Read from SKILL.md and the folder at commit 2000ef8. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • cargo

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Rust Engineer loads about 1.5k tokens when it runs, and up to ~12k if it reads all its reference files. Until then it costs about 156 tokens; SKILL.md has 329 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~156

When it runs · the whole SKILL.md, loaded when a task matches

~1.5k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~12k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from farm-fe/farm at commit 2000ef8, republished under its MIT licence (© farm-fe). 329 words, ~1,477 tokens.

name

rust-engineer

description

Writes, reviews, and debugs idiomatic Rust code with memory safety and zero-cost abstractions. Implements ownership patterns, manages lifetimes, designs trait hierarchies, builds async applications with tokio, and structures error handling with Result/Option. Use when building Rust applications, solving ownership or borrowing issues, designing trait-based APIs, implementing async/await concurrency, creating FFI bindings, or optimizing for performance and memory safety. Invoke for Rust, Cargo, ownership, borrowing, lifetimes, async Rust, tokio, zero-cost abstractions, memory safety, systems programming.

license

MIT

metadata.author

https://github.com/Jeffallan

metadata.version

1.1.0

metadata.domain

language

metadata.triggers

Rust, Cargo, ownership, borrowing, lifetimes, async Rust, tokio, zero-cost abstractions, memory safety, systems programming

metadata.role

specialist

metadata.scope

implementation

metadata.output-format

code

metadata.related-skills

test-master

// Explicit lifetime annotation — borrow lives as long as the input slice
fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
    if x.len() > y.len() { x } else { y }
}

// Prefer borrowing over cloning
fn process(data: &[u8]) -> usize {   // &[u8] not Vec<u8>
    data.iter().filter(|&&b| b != 0).count()
}

use std::fmt;

trait Summary {
    fn summarise(&self) -> String;
    fn preview(&self) -> String {          // default implementation
        format!("{}...", &self.summarise()[..50])
    }
}

#[derive(Debug)]
struct Article { title: String, body: String }

impl Summary for Article {
    fn summarise(&self) -> String {
        format!("{}: {}", self.title, self.body)
    }
}

use thiserror::Error;

#[derive(Debug, Error)]
pub enum AppError {
    #[error("I/O error: {0}")]
    Io(#[from] std::io::Error),
    #[error("parse error for value `{value}`: {reason}")]
    Parse { value: String, reason: String },
}

// ? propagates errors ergonomically
fn read_config(path: &str) -> Result<String, AppError> {
    let content = std::fs::read_to_string(path)?;  // Io variant via #[from]
    Ok(content)
}

use tokio::time::{sleep, Duration};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let result = fetch_data("https://example.com").await?;
    println!("{result}");
    Ok(())
}

async fn fetch_data(url: &str) -> Result<String, reqwest::Error> {
    let body = reqwest::get(url).await?.text().await?;
    Ok(body)
}

// Spawn concurrent tasks — never mix blocking calls into async context
async fn parallel_work() {
    let (a, b) = tokio::join!(
        sleep(Duration::from_millis(100)),
        sleep(Duration::from_millis(100)),
    );
}

cargo fmt --check                          # style check
cargo clippy --all-targets --all-features  # lints
cargo test                                 # unit + integration tests
cargo test --doc                           # doctests
cargo bench                                # criterion benchmarks (if present)

© farm-fe, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 5 other files (references) in .agents/skills/rust-engineer of farm-fe/farm.

• SKILL.md
• references/async.md
• references/error-handling.md
• references/ownership.md
• references/testing.md
• references/traits.md

Open the folder on GitHubat commit 2000ef8

Used in 1 other repository

We found 2 copies of this SKILL.md (exact, near-identical or edited) in other folders, from 1 other GitHub owner. This page covers the copy in farm-fe/farm, which our catalogue first saw on October 7, 2026.

• Jeffallan/claude-skillsskills/rust-engineer