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.
npx agentmods add skills/dirien/yet-another-agent-harness/rust-engineernpx skills add dirien/yet-another-agent-harness --skill rust-engineergit clone --depth 1 https://github.com/dirien/yet-another-agent-harnessWrote 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.
[](https://agentmods.dev/skills/dirien/yet-another-agent-harness/rust-engineer)<a href="https://agentmods.dev/skills/dirien/yet-another-agent-harness/rust-engineer"><img src="https://agentmods.dev/badge/skills/dirien/yet-another-agent-harness/rust-engineer.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00120 | $0.01388 |
| Opus 5 | $0.00060 | $0.00694 |
| Sonnet 5 | $0.00024 | $0.00278 |
| Haiku 4.5 | $0.00012 | $0.00139 |
Grade A, and why
rust-engineer 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 4d 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.
This is a copy
95% identical to rust-engineer — 2 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 168 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Rust Engineer
Senior Rust engineer with deep expertise in Rust 2021 edition, systems programming, memory safety, and zero-cost abstractions. Specializes in building reliable, high-performance software leveraging Rust's ownership system.
Core Workflow
- Analyze ownership — Design lifetime relationships and borrowing patterns; annotate lifetimes explicitly where inference is insufficient
- Design traits — Create trait hierarchies with generics and associated types
- Implement safely — Write idiomatic Rust with minimal unsafe code; document every
unsafeblock with its safety invariants - Handle errors — Use
Result/Optionwith?operator and custom error types viathiserror - Validate — Run
cargo clippy --all-targets --all-features,cargo fmt --check, andcargo test; fix all warnings before finalising
Reference Guide
Load detailed guidance based on context:
| Topic | Reference | Load When |
|---|---|---|
| Ownership | references/ownership.md |
Lifetimes, borrowing, smart pointers, Pin |
| Traits | references/traits.md |
Trait design, generics, associated types, derive |
| Error Handling | references/error-handling.md |
Result, Option, ?, custom errors, thiserror |
| Async | references/async.md |
async/await, tokio, futures, streams, concurrency |
| Testing | references/testing.md |
Unit/integration tests, proptest, benchmarks |
Key Patterns with Examples
Ownership & Lifetimes
// 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()
}
Trait-Based Design
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)
}
}
What ships with it
5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 4d ago First seen · 168 lines · 120 tokens per session scan A 2d2f54b45fa2
rust-engineer is a skill published in the GitHub repository dirien/yet-another-agent-harness (20 stars, last pushed 3mo ago), licensed MIT. It adds 120 tokens to every session and 1,388 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. It is 95% identical to rust-engineer, differing in 2 lines, and is treated as a copy.
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