progressive-enhancement

progressive-enhancement is a skill for Claude Code, Codex from mgifford/accessibility-skills. It costs 73 tokens per session (2,151 once invoked), scanned A, original, AGPL-3.0.

A web-development rule set based on progressive enhancement: start with semantic HTML, add CSS improvements, and use JavaScript as an extra layer.

In plain words
What is it for?
Use it when building web features, reviewing design decisions, or assessing JavaScript dependencies.
Why use it?
It helps keep a web feature usable when JavaScript is disabled, unavailable, or broken.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing.

Good fit Use it when building web features, reviewing design decisions, or assessing JavaScript dependencies.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/mgifford/accessibility-skills/progressive-enhancement
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 mgifford/accessibility-skills --skill progressive-enhancement
Clone the repo
git clone --depth 1 https://github.com/mgifford/accessibility-skills

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 progressive-enhancement

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

Your own site · 80×15
<a href="https://agentmods.dev/skills/mgifford/accessibility-skills/progressive-enhancement"><img src="https://agentmods.dev/badge/skills/mgifford/accessibility-skills/progressive-enhancement.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 73 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,151 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown 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 $0.00073 $0.02151
Opus 5 $0.00036 $0.01076
Sonnet 5 $0.00015 $0.00430
Haiku 4.5 $0.00007 $0.00215

Measured 11d ago against content hash c0a024ccacba, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

progressive-enhancement scanned grade A with 1 finding 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 11d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

fetch(event.request).catch(() => caches.match(OFFLINE_URL))
skills/progressive-enhancement/SKILL.md · 269 lines

The source is not reproduced here

Licensed AGPL-3.0

The repository is licensed AGPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 11d ago First seen · 269 lines · 73 tokens per session scan A c0a024ccacba

Subscribe to this mod's changes

progressive-enhancement is a skill published in the GitHub repository mgifford/accessibility-skills (44 stars, last pushed 2d ago), licensed AGPL-3.0. It adds 73 tokens to every session and 2,151 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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