Agent skill

Performance Audit

Audit and improve SwiftUI runtime performance. An agent skill from termio-sh/termio.

MITAuto-check passedMobile

Install Performance Audit

skills CLI

$ npx skills add termio-sh/termio --skill performance-audit -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install termio-sh/termio performance-audit --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/termio-sh/termio.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/swiftui-performance-audit .claude/skills/performance-audit && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "performance-audit" agent skill from https://github.com/termio-sh/termio/tree/main/skills/swiftui-performance-audit into .claude/skills/performance-audit/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "performance-audit", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/termio-sh/termio/tree/main/skills/swiftui-performance-audit

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add termio-sh/termio --skill performance-audit -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install termio-sh/termio performance-audit --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/termio-sh/termio.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/swiftui-performance-audit .agents/skills/performance-audit && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "performance-audit" agent skill from https://github.com/termio-sh/termio/tree/main/skills/swiftui-performance-audit into .agents/skills/performance-audit/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "performance-audit", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add termio-sh/termio --skill performance-audit -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install termio-sh/termio performance-audit --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/termio-sh/termio.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/swiftui-performance-audit .cursor/skills/performance-audit && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "performance-audit" agent skill from https://github.com/termio-sh/termio/tree/main/skills/swiftui-performance-audit into .cursor/skills/performance-audit/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "performance-audit", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/termio-sh/termio.git --path skills/swiftui-performance-audit

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add termio-sh/termio --skill performance-audit -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install termio-sh/termio performance-audit --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/termio-sh/termio.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/swiftui-performance-audit .gemini/skills/performance-audit && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "performance-audit" agent skill from https://github.com/termio-sh/termio/tree/main/skills/swiftui-performance-audit into .gemini/skills/performance-audit/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "performance-audit", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install termio-sh/termio performance-audit

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add termio-sh/termio --skill performance-audit -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/termio-sh/termio.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/swiftui-performance-audit .github/skills/performance-audit && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "performance-audit" agent skill from https://github.com/termio-sh/termio/tree/main/skills/swiftui-performance-audit into .github/skills/performance-audit/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "performance-audit", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add termio-sh/termio --skill performance-audit -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install termio-sh/termio performance-audit --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/termio-sh/termio.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/swiftui-performance-audit .opencode/skills/performance-audit && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "performance-audit" agent skill from https://github.com/termio-sh/termio/tree/main/skills/swiftui-performance-audit into .opencode/skills/performance-audit/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "performance-audit", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: performance-audit
GitHub stars: 540
Token cost: ~1.2k tokens
SKILL.md length: 360 words
Files: 1
Skills in repo: 19
Repo updated: Oct 6, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Audit and improve SwiftUI runtime performance. An agent skill from termio-sh/termio.

Works in 5 steps: Code-First Review → Guide User to Profile → Common Code Smells (and Fixes) → …
Requests to diagnose slow rendering
SKILL.md covers Overview, Workflow Decision Tree, 1. Code-First Review and 2. Guide User to Profile, plus 6 more sections
Calls xcodebuild

What it does

Performance Audit is an agent skill from termio-sh/termio. Audit and improve SwiftUI runtime performance. Use for requests to diagnose slow rendering, janky scrolling, high CPU/memory usage, excessive view updates, or layout thrash in SwiftUI apps.

Its SKILL.md is about 1.2k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Mobile, covering iOS development. It works with SwiftUI. The repository describes itself as: A terminal-first agentic development environment for agentic coding. Build for CLI/TUI agent. Runtime for Coding Agent, Tmux alternative. The licence is MIT.

When your agent uses it

Requests to diagnose slow rendering
Janky scrolling
High CPU/memory usage
Excessive view updates

Example prompts

“/performance-audit”

Workflow steps

5 steps, taken from the step headings in SKILL.md.

Code-First Review
Guide User to Profile
Common Code Smells (and Fixes)
Remediation Strategies
Verify

What it can do on your machine

Read from SKILL.md and the folder at commit 1a47d10. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
- xcodebuild
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Performance Audit loads about 1.2k tokens when it runs. Until then it costs about 52 tokens; SKILL.md has 360 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~52
When it runs · the whole SKILL.md, loaded when a task matches: ~1.2k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from termio-sh/termio at commit 1a47d10, republished under its MIT licence (© termio-sh). 360 words, ~1,161 tokens.

Download SKILL.mdSave it as .claude/skills/performance-audit/SKILL.md (or your agent's skills folder).

name: performance-audit
description: Audit and improve SwiftUI runtime performance. Use for requests to diagnose slow rendering, janky scrolling, high CPU/memory usage, excessive view updates, or layout thrash in SwiftUI apps.

SwiftUI Performance Audit

Overview

Audit SwiftUI view performance from instrumentation and baselining to root-cause analysis and concrete remediation steps.

Workflow Decision Tree

If user provides code: Start with Code-First Review
If user only describes symptoms: Ask for minimal code/context, then Code-First Review
If code review is inconclusive: Guide user to profile with Instruments

1. Code-First Review

Collect

Target view/feature code
Data flow: state, environment, observable models
Symptoms and reproduction steps

Focus On

View invalidation storms from broad state changes
Unstable identity in lists (id churn, UUID() per render)
Heavy work in body (formatting, sorting, image decoding)
Layout thrash (deep stacks, GeometryReader, preference chains)
Large images without downsampling
Over-animated hierarchies (implicit animations on large trees)

Provide

Likely root causes with code references
Suggested fixes and refactors
Minimal repro or instrumentation suggestion if needed

2. Guide User to Profile

If code review is inconclusive, explain how to collect data:

Use SwiftUI template in Instruments (Release build)
Reproduce the exact interaction (scroll, navigation, animation)
Capture SwiftUI timeline and Time Profiler
Export or screenshot relevant lanes and call tree

Ask for:

Trace export or screenshots
Device/OS/build configuration

3. Common Code Smells (and Fixes)

Expensive formatters in `body`

Bad:

swift

var body: some View {
    let formatter = NumberFormatter()  // Slow allocation every render
    Text(formatter.string(from: value))
}

Good:

swift

final class Formatters {
    static let number = NumberFormatter()
}

var body: some View {
    Text(Formatters.number.string(from: value))
}

Computed properties with heavy work

Bad:

swift

var filtered: [Item] {
    items.filter { $0.isEnabled }  // Runs every body eval
}

Good:

swift

@State private var filtered: [Item] = []

.onChange(of: items) {
    filtered = items.filter { $0.isEnabled }
}

Sorting/filtering in ForEach

Bad:

swift

ForEach(items.sorted(by: sortRule)) { item in
    Row(item)
}

Good:

swift

let sortedItems = items.sorted(by: sortRule)  // Compute once
ForEach(sortedItems) { item in
    Row(item)
}

Show full SKILL.md (146 more words)Show less

Unstable identity

Bad:

swift

ForEach(items, id: \.self) { item in  // \.self may not be stable
    Row(item)
}

Good:

swift

ForEach(items, id: \.stableID) { item in
    Row(item)
}

Image decoding on main thread

Bad:

swift

Image(uiImage: UIImage(data: data)!)

Good:

swift

// Decode/downsample off main thread, cache the result
@State private var image: UIImage?

.task {
    image = await ImageLoader.load(data: data, targetSize: size)
}

Broad dependencies in observable models

Bad:

swift

@Observable class Model {
    var items: [Item] = []
}

var body: some View {
    Row(isFavorite: model.items.contains(item))  // Entire array dependency
}

Good:

swift

// Granular view models or per-item state to reduce update fan-out

4. Remediation Strategies

Issue	Fix
Broad state changes	Narrow scope with `@State`/`@Observable` closer to leaves
Unstable identities	Use stable, unique IDs for `ForEach`
Heavy work in body	Precompute, cache, move to `@State`
Expensive subtrees	Use `equatable()` or value wrappers
Large images	Downsample before rendering
Layout complexity	Reduce nesting, use fixed sizing where possible

5. Verify

Ask user to re-run same capture and compare with baseline:

CPU usage
Frame drops
Memory peak

Output Format

Provide:

Metrics table (before/after if available)
Top issues (ordered by impact)
Proposed fixes with estimated effort

Profiling Commands

bash

# Build for profiling
xcodebuild -scheme MyApp -configuration Release -destination 'platform=iOS Simulator,name=iPhone 15 Pro' build

# Open in Instruments
open -a Instruments

Instruments Checklist

Use Release build (not Debug)
Select SwiftUI template
Reproduce exact problematic interaction
Look at SwiftUI timeline for body evaluations
Check Time Profiler for hot spots
Note frame rate drops in Animation timeline

Files

Just SKILL.md in skills/swiftui-performance-audit of termio-sh/termio.

Open the folder on GitHubat commit 1a47d10

Compare with similar skills

Performance Audit next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Performance Audit compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Performance Audit this skilltermio-sh/termio	540	—	~1.2k	Automated safety check: Pass	MIT	yesterday
Swiftui Protwostraws/SwiftUI-Agent-Skill	5k	2 repos	~1k	Automated safety check: Pass	MIT	5 mo ago
Swiftui UI PatternsAFK-surf/OpenBridge	430	4 repos	~887	Automated safety check: Pass	MIT	3 mo ago
Swiftui Performance Auditharperreed/dotfiles	334	8 repos	~1.4k	Automated safety check: Pass	None	4 days ago
Hig Project Contextraintree-technology/hig-doctor	142	5 repos	~1.2k	Automated safety check: Pass	MIT	26 days ago
Hig Components Contentraintree-technology/hig-doctor	142	5 repos	~1.3k	Automated safety check: Pass	MIT	26 days ago

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Questions about Performance Audit

What does Performance Audit do?

Audit and improve SwiftUI runtime performance. An agent skill from termio-sh/termio. Performance Audit is an agent skill from termio-sh/termio. Audit and improve SwiftUI runtime performance.

When should I use Performance Audit?

Performance Audit fits situations like: requests to diagnose slow rendering; janky scrolling; high CPU/memory usage; excessive view updates.

How do I install Performance Audit in Claude Code?

Run `npx skills add termio-sh/termio --skill performance-audit -a claude-code`. Or copy the skill folder (skills/swiftui-performance-audit in termio-sh/termio) into .claude/skills/performance-audit in your project. Claude Code loads it when a task matches its description.

How do I install Performance Audit in Codex?

Run `npx skills add termio-sh/termio --skill performance-audit -a codex`. Or copy the skill folder (skills/swiftui-performance-audit in termio-sh/termio) into .agents/skills/performance-audit in your project. Codex loads it when a task matches its description.

Can I use Performance Audit in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add termio-sh/termio --skill performance-audit -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/performance-audit, .gemini/skills/performance-audit, .github/skills/performance-audit and .opencode/skills/performance-audit in your project.

What does Performance Audit need to run?

Going by SKILL.md and its folder, Performance Audit needs the command-line tools its instructions call (xcodebuild).

Does Performance Audit access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Performance Audit safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Performance Audit use?

Performance Audit is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Performance Audit use?

About 1.2k tokens (SKILL.md is roughly 4.6k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Performance Audit?

Skills that share tags, products or a category with Performance Audit: Swiftui Pro (twostraws/SwiftUI-Agent-Skill, 5k stars), Swiftui UI Patterns (AFK-surf/OpenBridge, 430 stars), Swiftui Performance Audit (harperreed/dotfiles, 334 stars) and Hig Project Context (raintree-technology/hig-doctor, 142 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Performance Audit?

termio-sh (a GitHub organization) maintains it in termio-sh/termio, which has 540 GitHub stars. The repository holds 19 skills in this directory. The repository was last updated on October 6, 2026.

Source: termio-sh/termio on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Performance Audit

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

SwiftUI Performance Audit

Overview

Workflow Decision Tree

1. Code-First Review

Collect

Focus On

Provide

2. Guide User to Profile

3. Common Code Smells (and Fixes)

Expensive formatters in body

Computed properties with heavy work

Sorting/filtering in ForEach

Unstable identity

Image decoding on main thread

Broad dependencies in observable models

4. Remediation Strategies

5. Verify

Output Format

Profiling Commands

Instruments Checklist

Files

Compare with similar skills

Similar skills

More from termio-sh/termio

Related

Questions about Performance Audit

Expensive formatters in `body`