tools/xcprof/testdata/toc.xml and network-toc.xml carried the maintainer's IOPlatformUUID in the trace's <device> node, next to model="Mac Studio" and os-version="26.5 (25F71)". Verified against `ioreg -d2 -c IOPlatformExpertDevice`, which returns the same value. It entered in2a82c80aand was re-added in427d4922. Replaced with the RFC 4122 canonical placeholder, which the scanner already recognizes. No code parses that node's uuid — the toc tests read duration and family data — so the change is inert, confirmed by the xcprof suite and the unit suite. The warn tier is what surfaced this, so the tier stays populated rather than being silenced. Two changes reduce it on merit instead: the 4C4C44 prefix joins the recognized placeholder shapes (ASCII "LLD"; a real UUID carrying those three bytes has probability ~1/16.7M), and the removed value is simply gone. Tier 16 -> 8, and the remainder is four OS-binary identifiers plus one captured devicectl session id. Verified: 518/518 unit tests, xcprof go tests, leak scan 0 errors over 1978 files.
Axiom
Battle-tested skills, agents, and tools for modern Apple OS development — Swift 6, SwiftUI, Liquid Glass, Apple Intelligence, and more. Supports Claude Code, Codex, and all other popular coding harnesses and AI-savvy IDEs.
What is Axiom?
Axiom gives AI coding assistants deep Apple OS development expertise — the kind that prevents data loss from bad migrations, catches memory leaks before users complain, and stops you from spending 30 minutes debugging a zombie xcodebuild process.
- 276 skills covering UI, data, concurrency, performance, networking, accessibility, and more
- 42 agents that autonomously scan for issues (memory leaks, concurrency violations, build problems)
- 17 commands for quick audits and diagnostics
- xclog — a built-in console capture tool that gives AI assistants access to simulator and device logs
- xcsym — a built-in crash symbolication tool for
.ips, MetricKit, and Apple's legacy.crashtext crashes, with automatic dSYM discovery and pattern categorization - xcui — a built-in tool to drive and validate the simulator UI and accessibility (tap by accessibility ID, dump the accessibility tree, check VoiceOver and Dynamic Type)
- xcprof — a built-in tool to record and analyze CPU/performance traces (xctrace) without opening Instruments
Every discipline skill is TDD-tested against real developer pressure scenarios. Learn more about quality.
OS 27 in progress. Axiom is on a 27.x beta that tracks Apple's OS 27 developer betas — OS-27 coverage lands continuously through the beta season. Guidance for OS 26 and earlier stays stable.
Installation
Claude Code (native plugin)
/plugin marketplace add CharlesWiltgen/Axiom
Then search for "axiom" in the /plugin menu and install.
Cursor (native plugin)
Axiom's generated Cursor plugin includes 27 skill routers, 42 agents, 17 /axiom-* commands, advisory hooks, and automatic discovery of its MCP server configuration. See the Cursor install and support guide for the macOS support boundary and local installation steps.
MCP (VS Code, Cursor MCP-only, Gemini CLI, and more)
See the MCP setup guide.
Pi (terminal coding agent)
pi install git:github.com/CharlesWiltgen/Axiom
One command installs the skills plus the /axiom-* commands and hooks. See the Pi setup guide.
Xcode (Claude Agent / Codex)
See the Xcode integration guide.
Getting Started
Skills activate automatically based on your questions. Just ask:
"I'm getting BUILD FAILED in Xcode"
"How do I fix Swift 6 concurrency errors?"
"My app has memory leaks"
"I need to add a database column safely"
"Show me what my app is logging"
"Symbolicate this crash file"
You can also use commands directly:
/axiom:console # Capture simulator console output
/axiom:analyze-crash # Parse and triage .ips, MetricKit, or .crash reports
/axiom:fix-build # Diagnose build failures
/axiom:audit memory # Scan for memory leaks
/axiom:audit concurrency # Check for data races
/axiom:health-check # Run all relevant auditors
Documentation
Full documentation, skill catalog, and guides at charleswiltgen.github.io/Axiom.
Community
- r/axiomdev — Version announcements with changelogs
- Report issues or request features
- Share usage patterns and questions