Aether WCAG Scanner

Name: Aether WCAG Scanner
Author: allchemylabs

by allchemylabsversion 1.0.8i★ –iRuns on your computer

Registry nameio.github.allchemylabs/aether-wcag-scanner

Install

Overview

Description from the maker (original English)

WCAG 2.1 AA accessibility scanner (Playwright + axe-core) with grounded, browser-verified fixes.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
UsageiNot measured yet★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Runs on your computer
Transport: stdio
Category: Web & browsers
You need to fill in: ALLCHEMY_API_KEY

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 1 of 1 passed
Runs on your computer with your user’s permissions (files, network, apps).
You fill in yourself: ALLCHEMY_API_KEY

Values marked secret are keys to your account. Never share them or paste them into a chat.

You need

npmNode.js installed (for the npx command)

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

{
  "mcpServers": {
    "aether-wcag-scanner": {
      "command": "npx",
      "args": [
        "-y",
        "@allchemylabs/aether-wcag-scanner"
      ],
      "env": {
        "ALLCHEMY_API_KEY": "your-value"
      }
    }
  }
}

Run this in your terminal

claude mcp add aether-wcag-scanner --env ALLCHEMY_API_KEY=your-value -- npx -y @allchemylabs/aether-wcag-scanner

Fill in the empty values before running it.

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "aether-wcag-scanner": {
      "command": "npx",
      "args": [
        "-y",
        "@allchemylabs/aether-wcag-scanner"
      ],
      "env": {
        "ALLCHEMY_API_KEY": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "aether-wcag-scanner": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@allchemylabs/aether-wcag-scanner"
      ],
      "env": {
        "ALLCHEMY_API_KEY": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This one runs on your computer, and ChatGPT can only connect to servers on the internet. Pick another app.

Your choice stays on this device in a cookie; no account needed.

Values you fill in

ALLCHEMY_API_KEY secret env
Beta API key from https://beta.allchemylabs.ai/?src=registry (optional: without it the scanner runs fully offline with template fixes)

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 7, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account allchemylabs, which owns the repo
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
– Not applicable
Endpoint responds
This one runs on your computer; there is no internet endpoint
– Not applicable
Sign-in with OAuth
Runs on your computer and uses local settings instead
… Not checked yet
No hidden instructions in tool descriptions
Runs on your computer; we can only read tool lists from internet endpoints

Compared with others in Web & browsersi

More stars than 0% of the other 881 servers in this category
Published to the registry more recently than 66% of the other 881 servers in this category
Basic checks equal to or better than 100% of the other 881 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is Aether WCAG Scanner safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

You need to fill in: ALLCHEMY_API_KEY

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed –, and the latest version (1.0.8) reached the registry 17 days ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need Node.js on your computer.

What can I use instead?

In the same category: Browser Use, Chrome DevTools MCP, MCP Server Browser

Alternatives

Servers in the same category from other makers, sorted by stars.

Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

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README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

Aether WCAG Scanner

An MCP server for Claude Code, Cursor, Codex and other coding agents that finds WCAG 2.1 AA accessibility violations and returns ready-to-apply fixes — not just a list of problems.

It drives a real browser (Playwright + axe-core) across desktop, tablet, and mobile viewports, then pairs each violation with a concrete fix: corrected HTML, the relevant WCAG success criteria, and technique code examples.

It works free without a key. For higher quality, contextual fixes, get a beta key at [beta.allchemylabs.ai](https://beta.allchemylabs.ai/?src=github) (sign in with GitHub).

Why it's different

An AI coding agent working from markup alone has to infer what a page does. Aether runs the page in a real browser, measures it with axe-core, and grounds every suggested fix in the WCAG spec, so the agent is working from measurements rather than inference.

	Coding agent alone	Aether, offline	Aether, with API key
How it looks at the page	Reads the HTML it is given	Renders the page in Chromium at desktop, tablet and mobile widths and runs axe-core	Same
What it can measure	Structure visible in the markup	What axe measures on the rendered page: contrast, accessible names, ARIA usage, focusable regions, landmarks	Same
Fix suggestions	From the model's general knowledge	Deterministic templates for the common rules	Templates first, then WCAG-corpus examples, then a model; every cited technique passes a grounding check
How fixes are checked	Not checked unless you set that up	axe re-run on the fixed element; reports what cleared and what regressed	Same
What each fix cites	Whatever the model recalls	The axe rule and its severity	The WCAG success criteria and techniques, with rejected candidates shown
Network	Depends on the agent	None; runs entirely on your machine	Fix requests go to the hosted engine; falls back to offline templates when it is unreachable

Install

/plugin marketplace add https://github.com/allchemylabs/claude-plugins.git

/plugin install aether-wcag-scanner@allchemylabs

Once the official Claude Code marketplace listing is live, you can also install it directly from there.

Installing with /plugin install inside Claude Code prompts for your Allchemy Labs API key; paste the key you got from beta.allchemylabs.ai. Installing from the terminal (claude plugin install …), or letting Claude run the install for you, does not prompt, so set the key afterwards with the command below. Run the same command to change the key later:

/plugin configure aether-wcag-scanner@allchemylabs

The first start installs the plugin's dependencies (about a minute) and the first scan downloads Chromium for Playwright. If /mcp shows the server as not connected right after install, wait a moment and run /reload-plugins.

Running without a key

The plugin asks for a key at install because the cloud fixes need one. The scanner itself runs locally and still works without a key (for example after a terminal install, or via npx): you get local template fixes for every violation. A beta key adds higher quality, contextual fixes from the hosted insights engine; get one at beta.allchemylabs.ai (sign in with GitHub). Set it via the prompt above, or put ALLCHEMY_API_KEY= in the .env of the project you are scanning.

Use it outside Claude Code (any MCP client)

The same server is published to npm and the MCP Registry as @allchemylabs/aether-wcag-scanner. Any MCP client that speaks stdio can run it:

"mcpServers": { "aether-wcag-scanner": { "command": "npx", "args": ["-y", "@allchemylabs/aether-wcag-scanner"], "env": { "ALLCHEMY_API_KEY": " " } } } }

The first scan downloads Playwright's Chromium once (about 500 MB on disk: the browser plus its headless shell). Without ALLCHEMY_API_KEY the scanner still runs fully offline and returns template fixes.

Claude Code gets the /wcag-scan skill, which drives the scan → review → fix → verify loop. Other agents only see the tool descriptions and the instructions the server sends at connect time, so for the same behaviour copy AGENTS.md into your project (Codex reads it natively; Cursor and Windsurf accept it as a rules file). Without it an agent may fetch the page HTML and guess instead of running the browser scan.

The 5 tools

Tool	What it does
`aether_scan_and_fix`	Recommended. Scan a URL — or a single-page app across routes via the `spa` block — and return violations with fixes, each verified on the real browser, in one call. Set `maxFixes: 0` for a fast scan-only pass.
`aether_get_fix`	Get a fix for one specific violation (verified on the real browser). Omit `html` to instead get a rule-level explanation — WCAG success criteria and technique examples.
`aether_verify_fix`	Deterministically verify a fix with real Playwright + axe — re-scan a URL or diff original vs fixed HTML. Reports whether the target cleared, any new regressions, and the net compliance delta.
`aether_check_html`	Analyze an HTML snippet for issues — no live URL or browser needed.
`aether_submit_feedback`	Rate a fix (useful / not useful) so the guidance engine keeps improving; your correction helps seed better fixes.

Just ask Claude naturally, e.g. *"check localhost:3000 for accessibility issues and fix them"* — it will pick the right tool.

The `/wcag-scan` skill

Run /wcag-scan for a guided workflow: scan → review violations → apply fixes → re-scan to verify → summarize. The skill orchestrates the tools above and edits your files in place.

Hooks

The plugin adds two hooks to Claude Code:

Session start: checks that the plugin's dependencies and Chromium are installed, and installs them on the first run.
After each edit: when Claude edits an HTML, JSX, TSX, Vue or Svelte file, a quick heuristic check (no browser) reports possible accessibility issues to Claude. It never blocks an edit, and its findings can be false positives.

To turn the post-edit check off in every project, run /plugin configure aether-wcag-scanner@allchemylabs and set Post-edit accessibility check to false. To turn it off (or back on) for one project, add this to that project's .claude/settings.local.json:

{ "env": { "AETHER_POSTEDIT_HOOK": "0" } }

Use "1" to turn it back on for that project. Restart Claude Code after either change.

Scanning single-page apps

Pass a spa block to aether_scan_and_fix instead of url:

{ "spa": { "entryUrl": "http://localhost:4200", "framework": "angular", "maxRoutes": 10 } }

entryUrl — where the app boots. Routes are discovered by crawling client-side links unless you list them in routes: [{ "path": "/settings", "name": "Settings" }].
framework — angular, react, vue, or omit to auto-detect.
maxRoutes — cap on discovered routes.

Navigation is client-side (the browser context and app state are kept between routes), and readiness is decided by a layered stability cascade — DOM quiet, framework hooks such as Angular testability, pending-request drain — never by Playwright's networkidle, which deadlocks on apps with long-polling or websockets. A config that sets networkIdle is rejected for that reason.

Requirements

Node.js >= 20
Chromium (installed automatically on first run)

Disclaimer

Aether is an accessibility analysis and guidance tool. Using the platform does not, by itself, make your website, application, or digital service conformant with WCAG, the ADA (including Title II), the European Accessibility Act, Section 508, EN 301 549, or any other accessibility law or standard.

Automated scans detect only a subset of accessibility barriers. A "zero issues" result means the scanner did not flag anything in its detection range — not that the property is legally compliant.

You remain responsible for:

reviewing findings with qualified people
fixing issues in the underlying code and content
conducting or commissioning manual testing and audits as needed
maintaining accessibility as the product changes
obtaining legal advice for your specific obligations

Aether does not provide legal advice and does not replace an accessibility audit or a VPAT/ACR prepared by a qualified auditor.

License

MIT for the client (this plugin). The hosted insights engine and related Allchemy Labs services are proprietary — see LICENSE and NOTICE.

Aether WCAG Scanner

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

Values you fill in

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Web & browsersi

Common questions

Alternatives

Browser Use

Chrome DevTools MCP

MCP Server Browser

README from the maker

Aether WCAG Scanner

Why it's different

Install

Running without a key

Use it outside Claude Code (any MCP client)

The 5 tools

The /wcag-scan skill

Hooks

Scanning single-page apps

Requirements

Disclaimer

License

The `/wcag-scan` skill