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 performancegit 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/performance)<a href="https://agentmods.dev/skills/rshankras/claude-code-apple-skills/performance"><img src="https://agentmods.dev/badge/skills/rshankras/claude-code-apple-skills/performance/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/performance"><img src="https://agentmods.dev/badge/skills/rshankras/claude-code-apple-skills/performance.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 | $0.00050 | $0.00377 |
| Opus 5.5 | $0.00020 | $0.00151 |
| Sonnet 5.5 | $0.00010 | $0.00075 |
| Haiku 4.5 | $0.00005 | $0.00038 |
Grade A, and why
performance 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.
What it actually says
Performance Skills
Diagnose and fix performance problems, from system-level profiling to SwiftUI render behavior.
When This Skill Activates
Use this skill when the user:
- Reports the app is slow, janky, or hanging
- Wants to profile with Instruments (Time Profiler, Allocations, Hangs)
- Is investigating memory issues, slow launches, or energy drain
- Sees SwiftUI views re-rendering too often or slow
bodyevaluations - Asks about view identity problems or
_printChanges()
Available Skills
Paths are relative to THIS file's directory — skills run with cwd set to the user's project, so resolve each path from this SKILL.md's own location.
| Skill | Read | Covers |
|---|---|---|
| profiling | profiling/SKILL.md |
Instruments workflows; hangs, memory, slow launch, energy diagnosis |
| swiftui-debugging | swiftui-debugging/SKILL.md |
Unnecessary re-renders, view identity, slow body evaluations |
How to Route
- Match the request to a row above — system-level symptoms → profiling; SwiftUI render symptoms → swiftui-debugging.
- Read that SKILL.md (relative to this file) plus any reference files it lists.
- Apply the guidance to the user's code.
What ships with it
11 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.
- profiling/energy-diagnostics.md 14 KB
- profiling/hitches.md 7.2 KB
- profiling/launch-optimization.md 19 KB
- profiling/memory-profiling.md 23 KB
- profiling/SKILL.md 12 KB
- profiling/time-profiler.md 22 KB
- swiftui-debugging/body-reevaluation.md 11 KB
- swiftui-debugging/common-pitfalls.md 13 KB
- swiftui-debugging/lazy-loading.md 9.3 KB
- swiftui-debugging/SKILL.md 14 KB
- swiftui-debugging/view-identity.md 7.7 KB
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 · 37 lines · 50 tokens per session scan A 169a0e491167
performance is a skill published in the GitHub repository rshankras/claude-code-apple-skills (830 stars, last pushed 3mo ago), licensed MIT. It adds 50 tokens to every session and 377 once invoked, about $0.0002 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…