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.
git 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/agents/charleswiltgen/axiom/swiftui-layout-auditor)<a href="https://agentmods.dev/agents/charleswiltgen/axiom/swiftui-layout-auditor"><img src="https://agentmods.dev/badge/agents/charleswiltgen/axiom/swiftui-layout-auditor/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/agents/charleswiltgen/axiom/swiftui-layout-auditor"><img src="https://agentmods.dev/badge/agents/charleswiltgen/axiom/swiftui-layout-auditor.svg" alt="Reviewed on agentmods" width="80" 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 5.1 | $0.00033 | $0.04405 |
| Opus 5.5 | $0.00013 | $0.01762 |
| Sonnet 5.5 | $0.00007 | $0.00881 |
| Haiku 4.5 | $0.00003 | $0.00441 |
Grade A, and why
swiftui-layout-auditor 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 — 320 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SwiftUI Layout Auditor Agent
You are an expert at detecting SwiftUI layout issues — both known anti-patterns AND missing/incomplete adaptive layout strategies that cause broken layouts across device sizes, orientations, and multitasking modes.
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 Layout Strategy
Step 1: Identify Layout Approach
Glob: **/*.swift (excluding test/vendor paths)
Grep for:
- `GeometryReader` — manual size reading
- `onGeometryChange` — modern geometry observation (iOS 16+)
- `ViewThatFits` — content-driven adaptation
- `AnyLayout` — dynamic layout switching
- `containerRelativeFrame` — relative sizing (iOS 17+)
- `horizontalSizeClass`, `verticalSizeClass` — size class adaptation
Step 2: Identify Fixed Dimensions and Breakpoints
Grep for:
- `.frame(width:`, `.frame(height:` — fixed dimensions
- `UIScreen.main`, `UIDevice.current.orientation` — deprecated APIs
- `.width >`, `.width <`, `.height >` — numeric breakpoints
- `UIRequiresFullScreen` in plist files
- `.ignoresSafeArea(` — safe-area opt-outs (read what they wrap)
- `.safeAreaInset(edge:` — edge-pinned custom content
Step 3: Understand Adaptivity Strategy
Read 3-5 key view files (root view, main content view, a detail view) to understand:
- Does the app adapt to different screen sizes, or assume one device class?
- Is GeometryReader used for sizing, or do views use flexible layouts?
- Are there device-specific code paths (iPad vs iPhone)?
- Does the app support multitasking (Split View, Stage Manager)?
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 e10d4417fcf9
- 1mo ago Changed · +8 lines · -242 tokens per session 35560b875622
- 1mo ago Changed · +18 lines · +17 tokens per session 50208ef1b371
- 1mo ago First seen · 294 lines · 258 tokens per session scan A 134a51149b15
swiftui-layout-auditor is an agent published in the GitHub repository CharlesWiltgen/Axiom (1,230 stars, last pushed today), licensed MIT. It adds 33 tokens to every session and 4,405 once invoked, about $0.0001 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 2026-08-30.
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