performance

performance is a skill for Claude Code, Codex from techtankto/techtank-site. It costs 45 tokens per session (221 once invoked), scanned A, original, MIT.

A set of rules for keeping websites fast while building or reviewing their front end. It covers loading the first screen, images, vector graphics, animation, and fonts.

In plain words
What is it for?
Use it when adding images, video, animation, or custom fonts, or when checking a page for loading and interaction slowdowns.
Why use it?
It helps prevent new design or media work from making a page slow, jump during loading, or respond late to input.

Skill for Claude CodeCodex

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/techtankto/techtank-site/performance
Any agent
npx skills add techtankto/techtank-site --skill performance
Clone the repo
git clone --depth 1 https://github.com/techtankto/techtank-site

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 performance

README.md
[![agentmods](https://agentmods.dev/badge/skills/techtankto/techtank-site/performance.svg)](https://agentmods.dev/skills/techtankto/techtank-site/performance)
Your own site
<a href="https://agentmods.dev/skills/techtankto/techtank-site/performance"><img src="https://agentmods.dev/badge/skills/techtankto/techtank-site/performance.svg" alt="Measured on agentmods" height="20"></a>
Per session 45 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 221 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 $0.00045 $0.00221
Opus 5 $0.00023 $0.00111
Sonnet 5 $0.00009 $0.00044
Haiku 4.5 $0.00005 $0.00022

Measured 3d ago against content hash 9bb966a22100, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

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 3d 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.

.agents/skills/performance/SKILL.md · 16 lines

What it actually says

Performance

Fast is a feature; the presentation layer never gets to make the site feel slow.

  1. LCP first. Fast LCP on desktop and mobile; the first screenful renders without layout shift.
  2. Images lazy-load below the fold. Decorative image layers (texture backgrounds, thumbnail walls) never block LCP.
  3. Vector geometry ships as optimized SVG: marks, lines, letterforms, not raster.
  4. The presentation layer has a budget. Entry and loading sequences are capped in duration; motion never blocks interactivity or input.
  5. Motion discipline. Durations, easings, and variants are defined once and imported: no ad-hoc magic numbers per component.
  6. Font loading causes no flash of invisible text and no layout shift on swap.
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. 3d ago First seen · 16 lines · 45 tokens per session scan A 9bb966a22100

Subscribe to this mod's changes

performance is a skill published in the GitHub repository techtankto/techtank-site (5 stars, last pushed 7d ago), licensed MIT. It adds 45 tokens to every session and 221 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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