Agent skill

Benchmark

Measure performance baselines and detect regressions across browser Core Web Vitals (LCP, INP, CLS, page weight), API endpoint latency percentiles, and build/test feedback times, with before/after…

MITAuto-check passedFrontend & Design

Install Benchmark

skills CLI

$ npx skills add affaan-m/ECC --skill benchmark -a claude-code

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

GitHub CLI

$ gh skill install affaan-m/ECC benchmark --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/affaan-m/ECC.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/benchmark .claude/skills/benchmark && 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 "benchmark" agent skill from https://github.com/affaan-m/ECC/tree/main/skills/benchmark into .claude/skills/benchmark/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "benchmark", 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/affaan-m/ECC/tree/main/skills/benchmark

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 affaan-m/ECC --skill benchmark -a codex

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

GitHub CLI

$ gh skill install affaan-m/ECC benchmark --agent codex

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

Manual copy

$ git clone --depth 1 https://github.com/affaan-m/ECC.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/benchmark .agents/skills/benchmark && 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 "benchmark" agent skill from https://github.com/affaan-m/ECC/tree/main/skills/benchmark into .agents/skills/benchmark/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "benchmark", 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 affaan-m/ECC --skill benchmark -a cursor

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

GitHub CLI

$ gh skill install affaan-m/ECC benchmark --agent cursor

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

Manual copy

$ git clone --depth 1 https://github.com/affaan-m/ECC.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/benchmark .cursor/skills/benchmark && 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 "benchmark" agent skill from https://github.com/affaan-m/ECC/tree/main/skills/benchmark into .cursor/skills/benchmark/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "benchmark", 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/affaan-m/ECC.git --path skills/benchmark

--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 affaan-m/ECC --skill benchmark -a gemini-cli

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

GitHub CLI

$ gh skill install affaan-m/ECC benchmark --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/affaan-m/ECC.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/benchmark .gemini/skills/benchmark && 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 "benchmark" agent skill from https://github.com/affaan-m/ECC/tree/main/skills/benchmark into .gemini/skills/benchmark/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "benchmark", 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 affaan-m/ECC benchmark

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 affaan-m/ECC --skill benchmark -a github-copilot

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

Manual copy

$ git clone --depth 1 https://github.com/affaan-m/ECC.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/benchmark .github/skills/benchmark && 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 "benchmark" agent skill from https://github.com/affaan-m/ECC/tree/main/skills/benchmark into .github/skills/benchmark/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "benchmark", 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 affaan-m/ECC --skill benchmark -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 affaan-m/ECC benchmark --agent opencode

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

Manual copy

$ git clone --depth 1 https://github.com/affaan-m/ECC.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/benchmark .opencode/skills/benchmark && 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 "benchmark" agent skill from https://github.com/affaan-m/ECC/tree/main/skills/benchmark into .opencode/skills/benchmark/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "benchmark", 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: benchmark
GitHub stars: 276k
Used in: 3 other repos
Token cost: ~654 tokens
SKILL.md length: 120 words
Files: 1
Skills in repo: 673
Repo updated: Oct 5, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Measure performance baselines and detect regressions across browser Core Web Vitals (LCP, INP, CLS, page weight), API endpoint latency percentiles, and build/test feedback times, with before/after…

Checking page speed
SKILL.md covers When to Use, How It Works, Output and Integration
Calls bundle
Responding to it feels slow reports

What it does

Benchmark is an agent skill from affaan-m/ECC. Measure performance baselines and detect regressions across browser Core Web Vitals (LCP, INP, CLS, page weight), API endpoint latency percentiles, and build/test feedback times, with before/after comparison stored in git-tracked .ecc/benchmarks JSON. Use when checking page speed, responding to 'it feels slow' reports, verifying launch performance targets, or comparing stack alternatives.

Its SKILL.md is about 650 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 Frontend & Design, covering Web performance and REST APIs. It works with Git. The repository describes itself as: The agent harness performance optimization system. Skills, instincts, memory, security, and research-first development for Claude Code, Codex, Opencode, Cursor and beyond. The licence is MIT.

When your agent uses it

Checking page speed
Responding to it feels slow reports
Verifying launch performance targets
Comparing stack alternatives

Example prompts

“it feels slow”
“/benchmark”

Requirements

Docker

What it can do on your machine

Read from SKILL.md and the folder at commit ef648e0. 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:
- bundle
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

Benchmark loads about 654 tokens when it runs. Until then it costs about 100 tokens; SKILL.md has 120 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~100
When it runs · the whole SKILL.md, loaded when a task matches: ~654

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 affaan-m/ECC at commit ef648e0, republished under its MIT licence (© affaan-m). 120 words, ~654 tokens.

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

name: benchmark
description: Measure performance baselines and detect regressions across browser Core Web Vitals (LCP, INP, CLS, page weight), API endpoint latency percentiles, and build/test feedback times, with before/after comparison stored in git-tracked .ecc/benchmarks JSON. Use when checking page speed, responding to 'it feels slow' reports, verifying launch performance targets, or comparing stack alternatives.
license: MIT
metadata.origin: ECC

Benchmark — Performance Baseline & Regression Detection

When to Use

Before and after a PR to measure performance impact
Setting up performance baselines for a project
When users report "it feels slow"
Before a launch — ensure you meet performance targets
Comparing your stack against alternatives

How It Works

Mode 1: Page Performance

Measures real browser metrics via browser MCP:

1. Navigate to each target URL
2. Measure Core Web Vitals:
   - LCP (Largest Contentful Paint) — target < 2.5s
   - CLS (Cumulative Layout Shift) — target < 0.1
   - INP (Interaction to Next Paint) — target < 200ms
   - FCP (First Contentful Paint) — target < 1.8s
   - TTFB (Time to First Byte) — target < 800ms
3. Measure resource sizes:
   - Total page weight (target < 1MB)
   - JS bundle size (target < 200KB gzipped)
   - CSS size
   - Image weight
   - Third-party script weight
4. Count network requests
5. Check for render-blocking resources

Mode 2: API Performance

Benchmarks API endpoints:

1. Hit each endpoint 100 times
2. Measure: p50, p95, p99 latency
3. Track: response size, status codes
4. Test under load: 10 concurrent requests
5. Compare against SLA targets

Mode 3: Build Performance

Measures development feedback loop:

1. Cold build time
2. Hot reload time (HMR)
3. Test suite duration
4. TypeScript check time
5. Lint time
6. Docker build time

Mode 4: Before/After Comparison

Run before and after a change to measure impact:

/benchmark baseline    # saves current metrics
# ... make changes ...
/benchmark compare     # compares against baseline

Output:

| Metric | Before | After | Delta | Verdict |
|--------|--------|-------|-------|---------|
| LCP | 1.2s | 1.4s | +200ms | WARNING: WARN |
| Bundle | 180KB | 175KB | -5KB | ✓ BETTER |
| Build | 12s | 14s | +2s | WARNING: WARN |

Output

Stores baselines in .ecc/benchmarks/ as JSON. Git-tracked so the team shares baselines.

Integration

CI: run /benchmark compare on every PR
Pair with /canary-watch for post-deploy monitoring
Pair with /browser-qa for full pre-ship checklist

Files

Just SKILL.md in skills/benchmark of affaan-m/ECC.

Open the folder on GitHubat commit ef648e0

Used in 3 other repositories

We found 4 copies of this SKILL.md (exact, near-identical or edited) in other folders, from 3 other GitHub owners. This page covers the copy in affaan-m/ECC, which our catalogue first saw on October 7, 2026.

Compare with similar skills

Benchmark 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.

Benchmark compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Benchmark this skillaffaan-m/ECC	276k	3 repos	~654	Automated safety check: Pass	MIT	5 days ago
Compare Array Bundle SizePostHog/posthog-js	628	—	~599	Automated safety check: Pass	Custom licence	yesterday
Modern Web GuidanceJetBrains/skills	366	3 repos	~1.4k	Automated safety check: Pass	Apache-2.0	3 mo ago
DeployHouseofmvps/ultraship	123	—	~4.1k	Automated safety check: Pass	MIT	3 mo ago
React Doctormakeplane/plane	61k	12 repos	~657	Automated safety check: Pass	AGPL-3.0	yesterday
Fixing Motion Performanceibelick/ui-skills	9.5k	5 repos	~1.4k	Automated safety check: Pass	MIT	2 days ago

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Questions about Benchmark

What does Benchmark do?

Measure performance baselines and detect regressions across browser Core Web Vitals (LCP, INP, CLS, page weight), API endpoint latency percentiles, and build/test feedback times, with before/after…. Benchmark is an agent skill from affaan-m/ECC.ecc/benchmarks JSON.

When should I use Benchmark?

Benchmark fits situations like: checking page speed; responding to it feels slow reports; verifying launch performance targets; comparing stack alternatives.

How do I install Benchmark in Claude Code?

Run `npx skills add affaan-m/ECC --skill benchmark -a claude-code`. Or copy the skill folder (skills/benchmark in affaan-m/ECC) into .claude/skills/benchmark in your project. Claude Code loads it when a task matches its description.

How do I install Benchmark in Codex?

Run `npx skills add affaan-m/ECC --skill benchmark -a codex`. Or copy the skill folder (skills/benchmark in affaan-m/ECC) into .agents/skills/benchmark in your project. Codex loads it when a task matches its description.

Can I use Benchmark 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 affaan-m/ECC --skill benchmark -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/benchmark, .gemini/skills/benchmark, .github/skills/benchmark and .opencode/skills/benchmark in your project.

What does Benchmark need to run?

Going by SKILL.md and its folder, Benchmark needs the command-line tools its instructions call (bundle). Our summary lists: Docker.

Does Benchmark 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 Benchmark 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 Benchmark use?

Benchmark is published under the MIT licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Benchmark use?

About 654 tokens (SKILL.md is roughly 2.6k 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 Benchmark?

Skills that share tags, products or a category with Benchmark: Compare Array Bundle Size (PostHog/posthog-js, 628 stars), Modern Web Guidance (JetBrains/skills, 366 stars), Deploy (Houseofmvps/ultraship, 123 stars) and React Doctor (makeplane/plane, 61k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Benchmark?

affaan-m (a GitHub user) maintains it in affaan-m/ECC, which has 275,546 GitHub stars. The repository holds 673 skills in this directory. The repository was last updated on October 5, 2026.

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

Install Benchmark

Facts

At a glance

What it does

When your agent uses it

Example prompts

Requirements

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Benchmark — Performance Baseline & Regression Detection

When to Use

How It Works

Mode 1: Page Performance

Mode 2: API Performance

Mode 3: Build Performance

Mode 4: Before/After Comparison

Output

Integration

Files

Used in 3 other repositories

Compare with similar skills

Similar skills

More from affaan-m/ECC

Related

Questions about Benchmark