m01-ownership

m01-ownership is a skill for Claude Code from moeru-ai/auv. It costs 96 tokens per session (1,057 once invoked), scanned A, original, Apache-2.0.

A Rust guide for ownership, borrowing, and lifetimes—the rules that determine who controls data, who may use it, and how long those uses remain valid.

In plain words
What is it for?
It helps decide when data should be owned, borrowed, cloned, shared, or returned, and relates common Rust error codes to those design choices.
Why use it?
It helps diagnose compiler errors caused by moved values, invalid references, or data being used beyond its valid scope.

Skill for Claude Code

Written for Claude Code: user-invocable in frontmatter. Also seen: installed under .agents/ (shared by several agents).

Good fit It helps decide when data should be owned, borrowed, cloned, shared, or returned, and relates common Rust error codes to those design choices.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/moeru-ai/auv/m01-ownership
View source ↗ moeru-ai/auv
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 moeru-ai/auv --skill m01-ownership
Clone the repo
git clone --depth 1 https://github.com/moeru-ai/auv

Made for: Claude Code.

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 m01-ownership

README.md
[![agentmods](https://agentmods.dev/badge/skills/moeru-ai/auv/m01-ownership/github.svg)](https://agentmods.dev/skills/moeru-ai/auv/m01-ownership)
Your own site
<a href="https://agentmods.dev/skills/moeru-ai/auv/m01-ownership"><img src="https://agentmods.dev/badge/skills/moeru-ai/auv/m01-ownership/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 m01-ownership

Your own site · 80×15
<a href="https://agentmods.dev/skills/moeru-ai/auv/m01-ownership"><img src="https://agentmods.dev/badge/skills/moeru-ai/auv/m01-ownership.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 96 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,057 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00096 $0.01057
Opus 5 $0.00048 $0.00528
Sonnet 5 $0.00019 $0.00211
Haiku 4.5 $0.00010 $0.00106

Measured 11d ago against content hash cb4ebbeefbba, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

m01-ownership 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 11d 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.

.agents/skills/m01-ownership/SKILL.md · 135 lines

How it starts

The opening of the file, as written. The whole thing — 135 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Ownership & Lifetimes

Layer 1: Language Mechanics

Core Question

Who should own this data, and for how long?

Before fixing ownership errors, understand the data's role:

  • Is it shared or exclusive?
  • Is it short-lived or long-lived?
  • Is it transformed or just read?

Error → Design Question

Error Don't Just Say Ask Instead
E0382 "Clone it" Who should own this data?
E0597 "Extend lifetime" Is the scope boundary correct?
E0506 "End borrow first" Should mutation happen elsewhere?
E0507 "Clone before move" Why are we moving from a reference?
E0515 "Return owned" Should caller own the data?
E0716 "Bind to variable" Why is this temporary?
E0106 "Add 'a" What is the actual lifetime relationship?

Thinking Prompt

Before fixing an ownership error, ask:

  1. What is this data's domain role?

    • Entity (unique identity) → owned
    • Value Object (interchangeable) → clone/copy OK
    • Temporary (computation result) → maybe restructure
  2. Is the ownership design intentional?

    • By design → work within constraints
    • Accidental → consider redesign
  3. Fix symptom or redesign?

    • If Strike 3 (3rd attempt) → escalate to Layer 2

Trace Up ↑

When errors persist, trace to design layer:

E0382 (moved value)
    ↑ Ask: What design choice led to this ownership pattern?
    ↑ Check: m09-domain (is this Entity or Value Object?)
    ↑ Check: domain-* (what constraints apply?)
Persistent Error Trace To Question
E0382 repeated m02-resource Should use Arc/Rc for sharing?
E0597 repeated m09-domain Is scope boundary at right place?
E0506/E0507 m03-mutability Should use interior mutability?

Trace Down ↓

From design decisions to implementation:

"Data needs to be shared immutably"
    ↓ Use: Arc<T> (multi-thread) or Rc<T> (single-thread)

"Data needs exclusive ownership"
    ↓ Use: move semantics, take ownership

"Data is read-only view"
    ↓ Use: &T (immutable borrow)

Read the full file on GitHub · 135 lines

Files

What ships with it

4 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. 11d ago First seen · 135 lines · 96 tokens per session scan A cb4ebbeefbba

Subscribe to this mod's changes

m01-ownership is a skill published in the GitHub repository moeru-ai/auv (27 stars, last pushed 2d ago), licensed Apache-2.0. It adds 96 tokens to every session and 1,057 once invoked, about $0.0005 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.