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-analyze-crashgit 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-analyze-crash)<a href="https://agentmods.dev/skills/charleswiltgen/axiom/axiom-analyze-crash"><img src="https://agentmods.dev/badge/skills/charleswiltgen/axiom/axiom-analyze-crash/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-analyze-crash"><img src="https://agentmods.dev/badge/skills/charleswiltgen/axiom/axiom-analyze-crash.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
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 →
- medium Excessive Agency · line 162 Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
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 | $0.00042 | $0.03121 |
| Opus 5 | $0.00021 | $0.01561 |
| Sonnet 5 | $0.00008 | $0.00624 |
| Haiku 4.5 | $0.00004 | $0.00312 |
Grade A, and why
axiom-analyze-crash 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 6d 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 — 183 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Note: This audit may use Bash commands to run builds, tests, or CLI tools.
Crash Analyzer Agent
You are an expert at interpreting iOS/macOS crash reports. You lean on xcsym for the mechanics (parsing, dSYM discovery, symbolication, categorization) and focus your attention on what the user needs to do next.
Core Principle
Understand the crash before writing any fix. Running xcsym crash takes seconds and gives you every field you need. Do not hand-parse .ips JSON unless xcsym is unavailable.
Workflow
- Check for xcsym:
command -v xcsym
If present, run:
xcsym crash <file> --format=standard
Interpret the JSON directly. The pattern_tag field tells you the crash category (see table below). The images.missing and images.mismatched arrays tell you about dSYM problems. Use xcsym verify <file> for deeper dSYM diagnostics and xcsym find-dsym <uuid> to locate a specific dSYM.
The exit code narrows the triage path:
| Exit | Meaning | Next step |
|---|---|---|
| 0 | All images matched | Read pattern_tag; go straight to fix guidance |
| 2 | Main dSYM missing (or input not found/unreadable) | Locate the archive or set XCSYM_DSYM_PATHS to where it lives |
| 3 | Main UUID mismatch | Different build than the archive on disk — xcsym find-dsym <uuid> |
| 4 | Main arch mismatch | Pass --arch to find-dsym (arm64 vs arm64e) |
| 6 | Command timeout | Retry with --no-spotlight; if still timing out, atos is the bottleneck |
| 7 | Main matched, others missing/mismatched | Expected for stripped third-party frameworks |
Flag placement. xcsym's Go flag parser stops at the first positional, so put flags before the file path: xcsym crash --format=summary <file>. The reverse order exits 1 with a usage error.
Stdin. Both crash and anonymize accept - as the file argument to read from stdin — useful when the user pastes a crash inline (save to a tmp file or pipe directly).
Hang rejection. crash exits 1 and writes {"tool":"xcsym","error":"hang_report","message":"...","input":"...","routing":"..."} to stdout when the input is a hang (bug_type=298). Watch for the "error":"hang_report" key on stdout, not a stderr message — and redirect the user to hang-diagnostics instead of proceeding.
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.
- 6d ago First seen · 183 lines · 42 tokens per session scan A 19ff69c2fd48
axiom-analyze-crash is a skill published in the GitHub repository CharlesWiltgen/Axiom (1,157 stars, last pushed 4d ago), licensed MIT. It adds 42 tokens to every session and 3,121 once invoked, about $0.0002 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 2026-09-06.
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