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/commands/charleswiltgen/axiom/axiom-modernize)<a href="https://agentmods.dev/commands/charleswiltgen/axiom/axiom-modernize"><img src="https://agentmods.dev/badge/commands/charleswiltgen/axiom/axiom-modernize/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/commands/charleswiltgen/axiom/axiom-modernize"><img src="https://agentmods.dev/badge/commands/charleswiltgen/axiom/axiom-modernize.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 | $0.00026 | $0.00253 |
| Opus 5 | $0.00013 | $0.00127 |
| Sonnet 5 | $0.00005 | $0.00051 |
| Haiku 4.5 | $0.00003 | $0.00025 |
Grade A, and why
axiom-modernize 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.
This is a copy
91% identical to modernize — 10 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
What it actually says
Modernize iOS Code
Delegate to the modernization-helper subagent to find legacy patterns and give you the migration path for each.
Shorthand for /axiom-audit modernization — same agent, fewer keystrokes.
What It Does
The agent will:
- Scan for
ObservableObject/@Publishedthat should become@Observable - Find
@StateObjectand@ObservedObjectthat should become@State/@Bindable - Flag deprecated SwiftUI APIs still in use, with their replacements
- Identify UIKit patterns that have a modern SwiftUI or scene-lifecycle equivalent
- Give a migration path per finding rather than a bare list, so you can adopt incrementally
Prefer Natural Language?
You can also trigger this agent by saying:
- "How do I migrate from ObservableObject to @Observable?"
- "Are there any deprecated APIs in my SwiftUI code?"
- "Update my code to use modern SwiftUI patterns"
- "Should I still use @StateObject?"
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.
- 5d ago First seen · 29 lines · 26 tokens per session scan A ae4e25f4cb88
axiom-modernize is a command published in the GitHub repository CharlesWiltgen/Axiom (1,155 stars, last pushed 2d ago), licensed MIT. It adds 26 tokens to every session and 253 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 91% identical to modernize, differing in 10 lines, and is treated as a copy.
Other commands, from other repositories
flutter-review
Review Flutter/Dart code for idiomatic patterns, widget best practices, state management, performance, accessibility, and security. Invokes the flutter-reviewer agent.
mobile-review
Senior-level deep review of an existing mobile app. Reads targeted source files to analyze architecture, code quality, robustness, performance, and security. Produces a prioritized findings report.
swift-critique
Critique SwiftUI code for patterns, design, clean code, accessibility, and performance.
analyze
Analyze iOS code for quality, performance, security, and review.
apple-check
Validate Apple patterns in modified Swift files. Runs the apple-patterns-check skill.
flutter-review
Review Flutter/Dart code for idiomatic patterns, widget best practices, state management, performance, accessibility, and security. Invokes the flutter-reviewer agent.