m12-lifecycle

m12-lifecycle is a skill for Claude Code from moeru-ai/auv. It costs 94 tokens per session (1,078 once invoked), scanned A, original, Apache-2.0.

A guide to managing how long resources live in Rust, from creation through cleanup. It covers patterns such as automatic cleanup, delayed setup, reusable pools, and scoped access.

In plain words
What is it for?
Use it when designing connection pools, lazy initialization, transactions, sessions, cleanup after errors, or code that releases resources when a scope ends.
Why use it?
It helps prevent resources such as database connections or transactions from being left open, cleaned up too early, or owned by the wrong part of the program.

Skill for Claude Code

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

Good fit Use it when designing connection pools, lazy initialization, transactions, sessions, cleanup after errors, or code that releases resources when a scope ends.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/moeru-ai/auv/m12-lifecycle
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 m12-lifecycle
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 m12-lifecycle

README.md
[![agentmods](https://agentmods.dev/badge/skills/moeru-ai/auv/m12-lifecycle.svg)](https://agentmods.dev/skills/moeru-ai/auv/m12-lifecycle)
Your own site
<a href="https://agentmods.dev/skills/moeru-ai/auv/m12-lifecycle"><img src="https://agentmods.dev/badge/skills/moeru-ai/auv/m12-lifecycle.svg" alt="Measured on agentmods" height="20"></a>
Per session 94 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,078 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 warn 7 Sept 2026
SkillSpector: 1 finding, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high YARA Match · line 124
    YARA rule matched a hack tool or exploit indicator (offensive tools, reconnaissance, privilege escalation, or exploit frameworks).
    Fix: Remove offensive tool references and exploit code. Legitimate agent skills should not contain penetration testing tools, exploit frameworks, or reconnaissance utilities.
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 $0.00094 $0.01078
Opus 5 $0.00047 $0.00539
Sonnet 5 $0.00019 $0.00216
Haiku 4.5 $0.00009 $0.00108

Measured 8d ago against content hash db6f0af49dcf, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

m12-lifecycle 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 8d 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/m12-lifecycle/SKILL.md · 178 lines

How it starts

The opening of the file, as written. The whole thing — 178 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Resource Lifecycle

Layer 2: Design Choices

Core Question

When should this resource be created, used, and cleaned up?

Before implementing lifecycle:

  • What's the resource's scope?
  • Who owns the cleanup responsibility?
  • What happens on error?

Lifecycle Pattern → Implementation

Pattern When Implementation
RAII Auto cleanup Drop trait
Lazy init Deferred creation OnceLock, LazyLock
Pool Reuse expensive resources r2d2, deadpool
Guard Scoped access MutexGuard pattern
Scope Transaction boundary Custom struct + Drop

Thinking Prompt

Before designing lifecycle:

  1. What's the resource cost?

    • Cheap → create per use
    • Expensive → pool or cache
    • Global → lazy singleton
  2. What's the scope?

    • Function-local → stack allocation
    • Request-scoped → passed or extracted
    • Application-wide → static or Arc
  3. What about errors?

    • Cleanup must happen → Drop
    • Cleanup is optional → explicit close
    • Cleanup can fail → Result from close

Trace Up ↑

To domain constraints (Layer 3):

"How should I manage database connections?"
    ↑ Ask: What's the connection cost?
    ↑ Check: domain-* (latency requirements)
    ↑ Check: Infrastructure (connection limits)
Question Trace To Ask
Connection pooling domain-* What's acceptable latency?
Resource limits domain-* What are infra constraints?
Transaction scope domain-* What must be atomic?

Trace Down ↓

To implementation (Layer 1):

"Need automatic cleanup"
    ↓ m02-resource: Implement Drop
    ↓ m01-ownership: Clear owner for cleanup

"Need lazy initialization"
    ↓ m03-mutability: OnceLock for thread-safe
    ↓ m07-concurrency: LazyLock for sync

"Need connection pool"
    ↓ m07-concurrency: Thread-safe pool
    ↓ m02-resource: Arc for sharing

Quick Reference

Pattern Type Use Case
RAII Drop trait Auto cleanup on scope exit
Lazy Init OnceLock, LazyLock Deferred initialization
Pool r2d2, deadpool Connection reuse
Guard MutexGuard Scoped lock release
Scope Custom struct Transaction boundaries

Read the full file on GitHub · 178 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. 8d ago First seen · 178 lines · 94 tokens per session scan A db6f0af49dcf

Subscribe to this mod's changes

m12-lifecycle is a skill published in the GitHub repository moeru-ai/auv (27 stars, last pushed today), licensed Apache-2.0. It adds 94 tokens to every session and 1,078 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.

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