modern-web-guidance

modern-web-guidance is a skill for Claude Code, Codex from GoogleChrome/modern-web-guidance-src. It costs 233 tokens per session (1,525 once invoked), scanned A, original, Apache-2.0.

A reference search tool for current web-development practices, covering HTML, CSS, and browser-based JavaScript.

In plain words
What is it for?
Use it before implementing web features or creating components to find relevant guidance for layouts, dialogs, popovers, loading behavior, and other browser tasks.
Why use it?
Web-browser features and recommended implementation patterns change over time, so it helps avoid relying on outdated advice when building web interfaces.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions CLAUDE.md; mentions Claude Code; mentions AGENTS.md.

Good fit Use it before implementing web features or creating components to find relevant guidance for layouts, dialogs, popovers, loading behavior, and other browser tasks.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/googlechrome/modern-web-guidance-src/modern-web-guidance
About the project

Modern Web Guidance is a source repository for coding-agent skills that provide web-platform guidance, recommended practices, and browser compatibility information. It helps coding agents choose newer web APIs and patterns when generating web applications. The catalogue skills are the guidance produced and maintained by this project.

GoogleChrome/modern-web-guidance-src · 1,022 stars · on GitHub · goo.gle

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 GoogleChrome/modern-web-guidance-src --skill modern-web-guidance
Clone the repo
git clone --depth 1 https://github.com/GoogleChrome/modern-web-guidance-src

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 modern-web-guidance

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

Your own site · 80×15
<a href="https://agentmods.dev/skills/googlechrome/modern-web-guidance-src/modern-web-guidance"><img src="https://agentmods.dev/badge/skills/googlechrome/modern-web-guidance-src/modern-web-guidance.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 233 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,525 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. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 5 findings, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium MCP Rug Pull · line 38
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 65
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 75
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 94
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 94
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
How audits are shown
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 $0.00233 $0.01525
Opus 5 $0.00117 $0.00763
Sonnet 5 $0.00047 $0.00305
Haiku 4.5 $0.00023 $0.00153

Measured 5d ago against content hash 2286c7bac00d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

modern-web-guidance 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 5d 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.

guides/modern-web-guidance/SKILL.md · 124 lines

How it starts

The opening of the file, as written. The whole thing — 124 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Modern Web Guidance

A skill to search for specific web development use cases and retrieve their corresponding best practice guides.

When to use

Must use this skill:

  • At the start of implementing any web feature.
  • Before creating a new component, to check if a standardized pattern already exists.
  • To avoid implementing ad-hoc solutions or loading large dependencies unnecessarily.

Usage Instructions

Step 1. Search Use Cases

Search with an action-oriented query summarizing what you want to achieve using the search command. Run modern-web-guidance directly with npx.

npx -y modern-web-guidance@latest search "<query>" --skill-version SKILL_VERSION

Example Output:

[
  {
    "id": "optimize-image-priority",
    "description": "Optimize the loading priority of Largest Contentful Paint (LCP) candidate images.",
    "category": "performance",
    "featuresUsed": [ "Fetch priority" ],
    "tokenCount": 985,
    "similarity": 0.7289
  },
  {
    "id": "defer-rendering-heavy-content",
    "description": "Reduce rendering times in content-heavy web pages by deferring rendering for offscreen content.",
    "category": "performance",
    "featuresUsed": [ "content-visibility", "hidden=\"until-found\"" ],
    "tokenCount": 1250,
    "similarity": 0.6961
  }
]

Note: If search results are vague, return no matches, or show low similarity scores, run the list command to browse all guides:

npx -y modern-web-guidance@latest list

Step 2. Retrieve Best Practices

Once you have a relevant id from the search results, call this script using the retrieve command to get the full guide. You can pass multiple IDs separated by commas.

npx -y modern-web-guidance@latest retrieve "<id>"

If the output is truncated, you must repeat the command but redirect to a file and read that file.

Example Output: The markdown content of the guide describing implementation steps...


Step 3. Verify Guidance Compliance

Read the full file on GitHub · 124 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. 5d ago Changed · -1 lines 2286c7bac00d
  2. 6d ago Changed · +4 lines ee692ab7b25d
  3. 10d ago First seen · 121 lines · 233 tokens per session scan A f48f3b223592

Subscribe to this mod's changes

modern-web-guidance is a skill published in the GitHub repository GoogleChrome/modern-web-guidance-src (1,022 stars, last pushed today), licensed Apache-2.0. It adds 233 tokens to every session and 1,525 once invoked, about $0.0012 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 2026-08-30.

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