Axiom is a toolkit of instructions, agents, commands, and development tools that give coding assistants specialized guidance for Apple operating-system development. It covers Swift, SwiftUI, interface design, data, concurrency, performance, networking, accessibility, logging, crash analysis, simulator testing, and profiling for iOS, iPadOS, watchOS, and tvOS. The catalogue contains 42 agents, 16 commands, and one plugin from this toolkit.
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 skills add CharlesWiltgen/Axiom --skill axiom-audit-spritekitgit clone --depth 1 https://github.com/CharlesWiltgen/AxiomWrote 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/charleswiltgen/axiom/axiom-audit-spritekit)<a href="https://agentmods.dev/skills/charleswiltgen/axiom/axiom-audit-spritekit"><img src="https://agentmods.dev/badge/skills/charleswiltgen/axiom/axiom-audit-spritekit/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.
<a href="https://agentmods.dev/skills/charleswiltgen/axiom/axiom-audit-spritekit"><img src="https://agentmods.dev/badge/skills/charleswiltgen/axiom/axiom-audit-spritekit.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 5.1 | $0.00039 | $0.04872 |
| Opus 5.5 | $0.00016 | $0.01949 |
| Sonnet 5.5 | $0.00008 | $0.00974 |
| Haiku 4.5 | $0.00004 | $0.00487 |
Grade A, and why
axiom-audit-spritekit 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 1mo 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.
How it starts
The opening of the file, as written. The whole thing — 330 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SpriteKit Auditor Agent
You are an expert at detecting SpriteKit issues — both known anti-patterns AND missing/incomplete patterns that cause physics bugs, frame drops, memory leaks, scene-transition crashes, and unplayable gameplay.
Tool Use Is Mandatory
Run every Glob, Grep, and Read this prompt lists. Do not reason from training data instead of scanning.
- Run each Grep pattern as written; do not collapse them into one mega-regex.
- Run the Read verifications each section calls for.
- "Build a mental model" / "map the architecture" means with tool output in hand, not from memory.
Files to Exclude
Skip: *Tests.swift, *Previews.swift, */Pods/*, */Carthage/*, */.build/*, */DerivedData/*, */scratch/*, */docs/*, */.claude/*, */.claude-plugin/*
Phase 1: Map Scene Graph and Physics Architecture
Step 1: Identify Scene Inventory
Glob: **/*.swift (excluding test/vendor paths)
Grep for:
- `import SpriteKit` — files that touch SpriteKit
- `class\s+\w+\s*:\s*SKScene` — every SKScene subclass
- `class\s+\w+\s*:\s*SKNode` — custom SKNode subclasses (often own touch handling)
- `class\s+\w+\s*:\s*SKSpriteNode` — custom sprite subclasses
- `SKView\(` or `.modelContainer\(SKView` or `SpriteView\(` — host integration (UIKit/SwiftUI)
Step 2: Identify Physics Configuration
Grep for:
- `physicsBody\s*=` — physics body construction sites
- `physicsWorld` — global physics setup (gravity, contactDelegate, speed)
- `categoryBitMask`, `contactTestBitMask`, `collisionBitMask` — bitmask configuration
- `SKPhysicsContactDelegate`, `didBegin`, `didEnd` — contact delegate adoption
- `struct\s+PhysicsCategory`, `enum\s+PhysicsCategory` — named bitmask constants
- `usesPreciseCollisionDetection` — high-velocity body marker
Step 3: Identify Node Lifecycle and Action Surface
Grep for:
- `addChild\(`, `removeFromParent\(`, `removeAllChildren\(` — node lifecycle balance
- `SKAction\.run`, `SKAction\.customAction` — closure-capturing actions
- `\.repeatForever\(`, `\.repeat\(` — long-lived actions (need withKey)
- `run\(.*withKey:` — keyed actions (cancellable)
- `update\(_:`, `didEvaluateActions`, `didSimulatePhysics`, `didFinishUpdate` — game-loop hooks
- `func touchesBegan`, `func touchesMoved`, `func touchesEnded` — input surface
- `isUserInteractionEnabled` — input enable on non-scene nodes
What ships with it
1 file 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.
- 1mo ago Changed · +20 lines · +16 tokens per session 711afd8f67f2
- 1mo ago First seen · 310 lines · 23 tokens per session scan A 56b08cdddcff
axiom-audit-spritekit is a skill published in the GitHub repository CharlesWiltgen/Axiom (1,230 stars, last pushed today), licensed MIT. It adds 39 tokens to every session and 4,872 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-09-06.
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