rust-core

rust-core is a skill for Claude Code, Codex from adonai-labs/agent-runway. It costs 82 tokens per session (681 once invoked), scanned A, original, MIT.

Rust implementation guidance for backend services and command-line tools, covering project structure, ownership, errors, testing, security, and monitoring.

In plain words
What is it for?
Use it to build Rust APIs, backend services, and command-line programs, including work with ownership, Tokio-based asynchronous code, errors, and tests.
Why use it?
It helps developers choose simple Rust designs and apply the language's safety rules without making services or tools harder to maintain.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions Claude Code.

Good fit Use it to build Rust APIs, backend services, and command-line programs, including work with ownership, Tokio-based asynchronous code, errors, and tests.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/adonai-labs/agent-runway/skill-rust-core
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 adonai-labs/agent-runway --skill skill-rust-core
Clone the repo
git clone --depth 1 https://github.com/adonai-labs/agent-runway

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-core

README.md
[![agentmods](https://agentmods.dev/badge/skills/adonai-labs/agent-runway/skill-rust-core/github.svg)](https://agentmods.dev/skills/adonai-labs/agent-runway/skill-rust-core)
Your own site
<a href="https://agentmods.dev/skills/adonai-labs/agent-runway/skill-rust-core"><img src="https://agentmods.dev/badge/skills/adonai-labs/agent-runway/skill-rust-core/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for rust-core

Your own site · 80×15
<a href="https://agentmods.dev/skills/adonai-labs/agent-runway/skill-rust-core"><img src="https://agentmods.dev/badge/skills/adonai-labs/agent-runway/skill-rust-core.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 82 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 681 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 $0.00082 $0.00681
Opus 5 $0.00041 $0.00341
Sonnet 5 $0.00016 $0.00136
Haiku 4.5 $0.00008 $0.00068

Measured 5d ago against content hash ec06c2a7f847, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

rust-core 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 5d 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.

src/stacks/rust/skill-rust-core/SKILL.md · 68 lines

How it starts

The opening of the file, as written. The whole thing — 68 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Rust Core

How to invoke

After agent-runway add rust, the skill is installed at .cursor/skills/rust-core/. Use:

  • Cursor: @rust-core or ask a Rust question while editing *.rs (rules auto-attach)
  • Claude Code: reference .agent-runway/skills/rust-core/SKILL.md or ask in context of Rust files

Examples:

  • How should I structure this Axum service?
  • Is this ownership correct or should I clone?
  • How do I test this handler without a real database?
  • Which error type should I use in this library vs application?

Not sure which skill to use? Start with /start — it classifies intent and routes to the right skill.


Guiding principles

Rust's type system and ownership model enforce correctness — let them do the work.

  • Prefer owned types and borrowing over complex lifetimes; readable code first
  • Start with the simplest module layout that works; split only when the file becomes hard to navigate
  • SOLID applies: single-responsibility modules, small focused traits, DI via trait objects or generics
  • DRY for business logic; avoid macro magic when a plain function would do
  • Async with Tokio for I/O-bound services; sync for CLIs and tools — do not default to async
  • No over-engineering: a struct with plain methods is usually the right start

What this skill helps with

  • Workspace and crate structure scaled to complexity
  • Ownership, borrowing, and lifetime patterns
  • Async services with Axum / Actix; CLI with Clap
  • Error handling: thiserror for libraries, anyhow for applications
  • Testing: unit (#[cfg(test)]), integration (tests/), property-based, HTTP
  • Security: OWASP Rust, dependency audit with cargo audit
  • Observability: tracing, OpenTelemetry, health endpoints

Skill files

File Contents
architecture.md Workspace layout, crate boundaries, config
patterns.md Ownership, error handling, service layer, trait-based DI
testing.md Unit, integration, HTTP handler testing, proptest
security.md Input validation, SQL injection, subprocess safety, cargo audit
observability.md tracing, OpenTelemetry, health endpoints
reference.md Cargo.toml, common commands, toolchain

Read the full file on GitHub · 68 lines

Files

What ships with it

6 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.

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. 5d ago First seen · 68 lines · 82 tokens per session scan A ec06c2a7f847

Subscribe to this mod's changes

rust-core is a skill published in the GitHub repository adonai-labs/agent-runway (2 stars, last pushed 19d ago), licensed MIT. It adds 82 tokens to every session and 681 once invoked, about $0.0004 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 2026-09-03.