Awesome-omni-skill xctrace-skill

Profile iOS/macOS app performance with Instruments (xctrace). Use when investigating CPU hotspots, memory leaks, animation hitches, or comparing performance before/after changes.

install

source · Clone the upstream repo

git clone https://github.com/diegosouzapw/awesome-omni-skill

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/diegosouzapw/awesome-omni-skill "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/backend/xctrace-skill" ~/.claude/skills/diegosouzapw-awesome-omni-skill-xctrace-skill && rm -rf "$T"

manifest: skills/backend/xctrace-skill/SKILL.md

source content

xctrace Skill

Profile and analyze app performance using Apple's Instruments toolchain via

xctrace

Quick Start

# 1. List available profiling templates
python scripts/trace_templates.py

# 2. Record a 10-second Time Profiler trace of your app
python scripts/trace_record.py --template "Time Profiler" --attach MyApp --time-limit 10s

# 3. Export trace data to JSON for analysis
python scripts/trace_export.py --input recording.trace --toc

# 4. Analyze a trace and get a summary
python scripts/trace_analyze.py --input recording.trace

All scripts support

--help

for detailed options and

--json

for machine-readable output.

Scripts

Profiling

trace_templates.py - List available Instruments templates
- Shows all templates: Time Profiler, Allocations, Leaks, SwiftUI, etc.
- Options:
```
--json
```
trace_record.py - Record a performance trace
- Profile by attaching to running app or launching
- Set time limits, output paths
- Options:
```
--template
```
  ,
```
--attach
```
  ,
```
--launch
```
  ,
```
--time-limit
```
  ,
```
--output
```
  ,
```
--all-processes
```
  ,
```
--json
```
trace_attach.py - Profile an already-running process
- Convenience wrapper for trace_record with --attach
- Options:
```
--pid
```
  ,
```
--name
```
  ,
```
--template
```
  ,
```
--time-limit
```
  ,
```
--output
```
  ,
```
--json
```

Analysis

trace_export.py - Export trace data
- Table of contents (--toc) or XPath queries
- Options:
```
--input
```
  ,
```
--output
```
  ,
```
--toc
```
  ,
```
--xpath
```
  ,
```
--json
```
trace_analyze.py - Generate performance summary
- Extracts key metrics from trace
- Identifies hotspots, allocations, issues
- Options:
```
--input
```
  ,
```
--verbose
```
  ,
```
--json
```
trace_compare.py - Compare two traces
- Before/after performance comparison
- Options:
```
--baseline
```
  ,
```
--current
```
  ,
```
--json
```

Binary Inspection

binary_inspect.py - Inspect Mach-O binaries
- View linked libraries, symbols, headers
- Useful for understanding crashes, dependencies
- Options:
```
--headers
```
  ,
```
--libraries
```
  ,
```
--symbols
```
  ,
```
--swift-symbols
```
  ,
```
--json
```

Common Templates

Template	Use Case
Time Profiler	CPU usage, find slow functions
Allocations	Memory usage, object lifetimes
Leaks	Memory leaks
SwiftUI	SwiftUI view body evaluations, identity changes
Animation Hitches	UI jank, dropped frames
App Launch	Startup time analysis
Network	HTTP requests, latency
Swift Concurrency	Actor isolation, task scheduling

Typical Workflows

"This screen is slow"

# Record while reproducing the issue
python scripts/trace_record.py --template "Time Profiler" --attach MyApp --time-limit 15s

# Analyze
python scripts/trace_analyze.py --input recording.trace

"App is using too much memory"

python scripts/trace_record.py --template "Allocations" --attach MyApp --time-limit 30s
python scripts/trace_analyze.py --input recording.trace

"Is my optimization working?"

# Record baseline
python scripts/trace_record.py --template "Time Profiler" --attach MyApp --output baseline.trace --time-limit 10s

# Make changes, rebuild, then record again
python scripts/trace_record.py --template "Time Profiler" --attach MyApp --output optimized.trace --time-limit 10s

# Compare
python scripts/trace_compare.py --baseline baseline.trace --current optimized.trace

"What's in this binary?"

python scripts/binary_inspect.py --libraries /path/to/MyApp.app/MyApp
python scripts/binary_inspect.py --swift-symbols /path/to/MyApp.app/MyApp

Requirements

macOS 12+
Xcode Command Line Tools
Python 3

Notes

Traces can be large (100MB+). Use
```
--time-limit
```
to keep them manageable.
Some templates require running on device (not simulator).
For GUI analysis, open
```
.trace
```
files in Instruments.app.