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 rshankras/claude-code-apple-skills --skill profilinggit clone --depth 1 https://github.com/rshankras/claude-code-apple-skillsWrote 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/rshankras/claude-code-apple-skills/profiling)<a href="https://agentmods.dev/skills/rshankras/claude-code-apple-skills/profiling"><img src="https://agentmods.dev/badge/skills/rshankras/claude-code-apple-skills/profiling/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/rshankras/claude-code-apple-skills/profiling"><img src="https://agentmods.dev/badge/skills/rshankras/claude-code-apple-skills/profiling.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00036 | $0.02826 |
| Opus 5.5 | $0.00014 | $0.01130 |
| Sonnet 5.5 | $0.00007 | $0.00565 |
| Haiku 4.5 | $0.00004 | $0.00283 |
Grade A, and why
performance-profiling 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 — 240 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Performance Profiling
Systematic guide for profiling Apple platform apps using Instruments, Xcode diagnostics, and MetricKit. Covers CPU, memory, launch time, and energy analysis with actionable fix patterns.
When This Skill Activates
Use this skill when the user:
- Reports app hangs, stutters, or dropped frames
- Needs to profile CPU usage or find hot code paths
- Has memory leaks, high memory usage, or OOM crashes
- Wants to optimize app launch time
- Needs to reduce battery/energy impact
- Asks about Instruments, Time Profiler, Allocations, or Leaks
- Wants to add
os_signpostor performance measurement to code - Is preparing for App Store review and needs performance validation
Decision Tree
What performance problem are you investigating?
│
├─ App hangs / unresponsive to taps / slow UI
│ └─ Read time-profiler.md
│
├─ Scroll or animation stutter / dropped frames / hitches
│ └─ Read hitches.md
│
├─ High memory / leaks / OOM crashes / growing footprint
│ └─ Read memory-profiling.md
│
├─ Slow app launch / time to first frame
│ └─ Read launch-optimization.md
│
├─ Battery drain / thermal throttling / background energy
│ └─ Read energy-diagnostics.md
│
├─ General "app feels slow" (unknown cause)
│ └─ Start with time-profiler.md, then memory-profiling.md
│
└─ Pre-release performance audit
└─ Read ALL reference files, use Review Checklist below
Quick Reference
| Problem | Instrument / Tool | Key Metric | Reference |
|---|---|---|---|
| UI hangs > 250ms | Time Profiler + Hangs | Hang duration, main thread stack | time-profiler.md |
| Scroll/animation hitches | Animation Hitches template | Hitch time ratio (< 5 ms/s good, > 10 critical) | hitches.md |
| High CPU usage | Time Profiler / CPU Profiler | CPU % by function, call tree weight | time-profiler.md |
| Memory leak | Leaks + Memory Graph | Leaked bytes, retain cycle paths | memory-profiling.md |
| Memory growth | Allocations | Live bytes, generation analysis | memory-profiling.md |
| Slow launch | App Launch | Time to first frame (pre-main + post-main) | launch-optimization.md |
| Battery drain | Energy Log / Power Profiler | Energy Impact score, CPU/GPU/network | energy-diagnostics.md |
| Thermal issues | Activity Monitor | Thermal state transitions | energy-diagnostics.md |
| Network waste | Network profiler | Redundant fetches, large payloads | energy-diagnostics.md |
What ships with it
5 files 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.
- 1mo ago First seen · 240 lines · 36 tokens per session scan A 55dbb26e0f78
performance-profiling is a skill published in the GitHub repository rshankras/claude-code-apple-skills (828 stars, last pushed 3mo ago), licensed MIT. It adds 36 tokens to every session and 2,826 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 2026-09-03.
Other skills, from other repositories
swift-performance-pro
Use when diagnosing or fixing performance — SwiftUI render cost, memory and retain cycles, slow lists, launch time, and using Instruments.
android-development
Android development with Kotlin, Jetpack Compose, and modern Android architecture. Use when building Android apps, implementing Material Design, or following Android best practices.
ios-development
Comprehensive guide for building native Apple platform applications.
agent-flutter-developer
Specialist subagent: Flutter/Dart cross-platform development, Riverpod state management, and platform channels specialist. Use when building Flutter apps, implementing state management, or working with native platform features. Trigger phrases: Flutter, Dart, Riverpod, Bloc, widget, MaterialApp, GoRouter, platform…
monitoring-observability
OpenTelemetry, structured logging, distributed tracing, alerting, and dashboards. Use when instrumenting services, designing logs/traces/metrics, defining SLOs and alerts, or debugging production behavior from telemetry.
agent-mobile-release-manager
Specialist subagent: App store submissions, mobile CI/CD, ASO, code signing, and beta distribution specialist. Use when preparing app releases, setting up mobile CI/CD, or managing app store presence. Trigger phrases: app store, Play Store, TestFlight, release, code signing, provisioning profile, Fastlane, ASO, beta…