ios-performance-debugging

ios-performance-debugging is a skill for Claude Code, Codex from memi-design/design-skills. It costs 33 tokens per session (276 once invoked), scanned A, original, MIT.

A structured process for finding performance problems in iOS apps, including SwiftUI interfaces. It uses repeatable user flows, measured metrics, diagnostic traces, targeted changes, and before-and-after comparisons.

In plain words
What is it for?
Use it to investigate rendering hitches, slow launches, unresponsive screens, concurrency issues, memory use, energy use, and simulator failures in SwiftUI or other iOS code.
Why use it?
Performance issues are easy to misdiagnose when changes are based only on intuition. The process connects measured slowdowns to source code and records evidence for any claimed improvement.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Install

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.

agentmods
npx agentmods add skills/memi-design/design-skills/ios-performance-debugging
Any agent
npx skills add memi-design/design-skills --skill ios-performance-debugging
Clone the repo
git clone --depth 1 https://github.com/memi-design/design-skills

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for ios-performance-debugging

README.md
[![agentmods](https://agentmods.dev/badge/skills/memi-design/design-skills/ios-performance-debugging.svg)](https://agentmods.dev/skills/memi-design/design-skills/ios-performance-debugging)
Your own site
<a href="https://agentmods.dev/skills/memi-design/design-skills/ios-performance-debugging"><img src="https://agentmods.dev/badge/skills/memi-design/design-skills/ios-performance-debugging.svg" alt="Measured on agentmods" height="20"></a>
Per session 33 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 276 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00033 $0.00276
Opus 5 $0.00016 $0.00138
Sonnet 5 $0.00007 $0.00055
Haiku 4.5 $0.00003 $0.00028

Measured 6d ago against content hash dc932b5ba084, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

ios-performance-debugging 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.

skills/ios-performance-debugging/SKILL.md · 28 lines

What it actually says

iOS Performance Debugging

Workflow

  1. Define one reproducible user flow and one metric before changing code.
  2. Capture device, OS, build configuration, commit, data fixture, and baseline trace.
  3. Use the narrowest instrument: SwiftUI updates and hitches, Time Profiler, Allocations/Leaks, Network, Energy, or concurrency analysis.
  4. Correlate the trace to source. Do not optimize from intuition alone.
  5. Change one ownership, identity, layout, allocation, or scheduling cause at a time.
  6. Repeat the same flow and compare the same metric.
  7. Keep the trace, command, and before-after result in the handoff.

SwiftUI checks

  • Stable identity in collections.
  • Observation scoped to data the view actually reads.
  • No expensive formatting, filtering, I/O, or object creation in body.
  • Lazy containers used only where they fit the layout.
  • Image decoding and resizing moved off the render-critical path.
  • Navigation and sheet state represented by one source of truth.

Read references/trace-receipt.md before claiming a performance improvement.

Files

What ships with it

2 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.

Changes

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.

  1. 6d ago First seen · 28 lines · 33 tokens per session scan A dc932b5ba084

Subscribe to this mod's changes

ios-performance-debugging is a skill published in the GitHub repository memi-design/design-skills (7 stars, last pushed 1mo ago), licensed MIT. It adds 33 tokens to every session and 276 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 2026-08-31.

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