canon-favicons

canon-favicons is a skill for Claude Code, Codex from Dragoon0x/canon. It costs 68 tokens per session (937 once invoked), scanned A, original, MIT.

A guide to the browser and device icons that identify a website or web app, including tab icons, home-screen icons, and progressive web app icons.

In plain words
What is it for?
Use it when implementing favicons, SVG and ICO icons, Apple touch icons, Android icons, or web app manifest declarations.
Why use it?
It helps the site display a recognizable icon across modern browsers, iOS, Android, and installed web apps instead of relying on one incomplete file.

Skill for Claude CodeCodex

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

Good fit Use it when implementing favicons, SVG and ICO icons, Apple touch icons, Android icons, or web app manifest declarations.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/dragoon0x/canon/canon-favicons
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.

Any agent
npx skills add Dragoon0x/canon --skill canon-favicons
Clone the repo
git clone --depth 1 https://github.com/Dragoon0x/canon

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 canon-favicons

README.md
[![agentmods](https://agentmods.dev/badge/skills/dragoon0x/canon/canon-favicons/github.svg)](https://agentmods.dev/skills/dragoon0x/canon/canon-favicons)
Your own site
<a href="https://agentmods.dev/skills/dragoon0x/canon/canon-favicons"><img src="https://agentmods.dev/badge/skills/dragoon0x/canon/canon-favicons/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.

agentmods 80×15 button for canon-favicons

Your own site · 80×15
<a href="https://agentmods.dev/skills/dragoon0x/canon/canon-favicons"><img src="https://agentmods.dev/badge/skills/dragoon0x/canon/canon-favicons.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 68 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 937 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 $0.00068 $0.00937
Opus 5 $0.00034 $0.00468
Sonnet 5 $0.00014 $0.00187
Haiku 4.5 $0.00007 $0.00094

Measured 12d ago against content hash 7ecee5cfb1cd, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

canon-favicons 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 12d 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.

source/skills/canon-favicons/SKILL.md · 99 lines

How it starts

The opening of the file, as written. The whole thing — 99 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CANON · Favicons

Favicons are the smallest piece of branding and the most often botched. Modern browsers need multiple sizes, formats, and declarations.

The minimal set

<link rel="icon" href="/favicon.ico" sizes="32x32">
<link rel="icon" href="/icon.svg" type="image/svg+xml">
<link rel="apple-touch-icon" href="/apple-touch-icon.png">
<link rel="manifest" href="/manifest.webmanifest">

Files to generate

File Size Format Purpose
favicon.ico 32×32 (can embed 16×16) ICO Legacy browsers, bookmarks bar
icon.svg Scalable SVG Modern browsers (Chrome, Firefox)
apple-touch-icon.png 180×180 PNG iOS home screen
icon-192.png 192×192 PNG Android home screen, PWA
icon-512.png 512×512 PNG PWA splash screen

SVG favicon with dark mode

SVG favicons can adapt to dark mode:

<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 32 32">
  <style>
    rect { fill: #0a0a0a; }
    @media (prefers-color-scheme: dark) {
      rect { fill: #f5f5f5; }
    }
  </style>
  <rect width="32" height="32" rx="4"/>
</svg>

Web app manifest

{
  "name": "My App",
  "short_name": "App",
  "icons": [
    { "src": "/icon-192.png", "sizes": "192x192", "type": "image/png" },
    { "src": "/icon-512.png", "sizes": "512x512", "type": "image/png" }
  ],
  "theme_color": "#0a0a0a",
  "background_color": "#ffffff",
  "display": "standalone"
}

theme_color affects the browser toolbar color on Android.

Design rules

  • Simple at 16px. If your logo doesn't read at 16×16, simplify it to a lettermark or geometric shape.
  • No text at small sizes. Text is illegible below 32px.
  • High contrast against both light and dark browser chrome. Test on light and dark OS themes.
  • Square. All favicon slots are square. Don't force a horizontal logo into a square; make a square variant.
  • No transparency for apple-touch-icon. iOS fills transparent areas with black. Use a solid background.

Read the full file on GitHub · 99 lines

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. 12d ago First seen · 99 lines · 68 tokens per session scan A 7ecee5cfb1cd

Subscribe to this mod's changes

canon-favicons is a skill published in the GitHub repository Dragoon0x/canon (6 stars, last pushed 4mo ago), licensed MIT. It adds 68 tokens to every session and 937 once invoked, about $0.0003 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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