# WSG Check (npm · @sustainablewebsites/wsg-check)

Check websites against the W3C Web Sustainability Guidelines and look up the guidelines

- Trust score: 80/100 (high trust)
- Change this week: 0
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-10-03

## Components

- npm · `@sustainablewebsites/wsg-check`: 80/100 (this document), [markdown](https://verifymcp.io/servers/ivanoats-wsg-check/sustainablewebsites-wsg-check.md), [page](https://verifymcp.io/servers/ivanoats-wsg-check/sustainablewebsites-wsg-check)

## Channel facts

- Registry: `npm`
- Package: `@sustainablewebsites/wsg-check`
- Version: `0.6.0`
- Transport: `stdio`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-10-03.

- **Supply Chain Security**: 98/100
  - No malware found by supply-chain analysis.
  - No known CVEs affecting this package version or its production dependencies.
  - No install/post-install scripts declared.
  - 38 of 133 dependencies flagged as unhealthy (1 deprecated).
- **Provenance & Transparency**: 97/100
  - Source repository is publicly reachable at the declared URL.
  - Cryptographically verified build provenance (signed, bound to ivanoats/wsg-check).
  - Clear OSI-approved license (Apache-2.0).
  - Actively maintained (last published 6 days ago).
  - Disclosure check failed: no security disclosure policy was found in the source repository.
- **Schema Quality & AI Usability**: 75/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 488 tokens (~162/item across 3 items; 3 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 0/100
  - Stability not yet verified: not enough scan history yet (needs a 30-day window).
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
  - Structured output schemas are declared (100% of tools); any adoption earns full credit.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 3 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 4 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.

**Unverified: 1 category.** A category scored 0 because we could not verify it: a data source with nothing on this package, evidence we could not reach, or a check we could not run. We only credit what we can confirm.

## Install

### How do I install the WSG Check MCP server?

WSG Check runs locally as an npm package, launched with npx -y @sustainablewebsites/wsg-check. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add ivanoats-wsg-check -- npx -y @sustainablewebsites/wsg-check
```

### Cursor

```json
{
  "mcpServers": {
    "ivanoats-wsg-check": {
      "command": "npx",
      "args": [
        "-y",
        "@sustainablewebsites/wsg-check"
      ]
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "ivanoats-wsg-check": {
      "command": "npx",
      "args": [
        "-y",
        "@sustainablewebsites/wsg-check"
      ]
    }
  }
}
```

### Codex

```bash
codex mcp add ivanoats-wsg-check -- npx -y @sustainablewebsites/wsg-check
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "ivanoats-wsg-check": {
      "type": "local",
      "command": [
        "npx",
        "-y",
        "@sustainablewebsites/wsg-check"
      ],
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add ivanoats-wsg-check --command npx --arg -y --arg @sustainablewebsites/wsg-check
```

### Hermes

```yaml
mcp_servers:
  ivanoats-wsg-check:
    command: "npx"
    args: ["-y", "@sustainablewebsites/wsg-check"]
```

### Netclaw

```json
{
  "McpServers": {
    "ivanoats-wsg-check": {
      "Transport": "stdio",
      "Command": "npx",
      "Arguments": [
        "-y",
        "@sustainablewebsites/wsg-check"
      ]
    }
  }
}
```

### Vellum

```bash
assistant mcp add ivanoats-wsg-check -t stdio -c npx -a -y @sustainablewebsites/wsg-check
```

### Other

```json
{
  "mcpServers": {
    "ivanoats-wsg-check": {
      "command": "npx",
      "args": [
        "-y",
        "@sustainablewebsites/wsg-check"
      ]
    }
  }
}
```

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-09-28 (score 80, 0)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

### 2026-09-26 (score 80)

First indexed and scored.

## MCP tools (3)

### `check_url` (~200 tokens)

Check a URL against the WSG

Fetches a page and checks it against the W3C Web Sustainability Guidelines. Returns the score, grade, and each failed or warned check with a recommended fix. Local URLs such as http://localhost:3000 are fetched from the user's machine; they work unless the server was started with --no-local.

Input parameters:

- `categories` (array): WSG categories to run. Defaults to all three.
- `detail` (string): "summary" (default) returns the score and the failed or warned checks. "full" also returns the complete report, which is much longer.
- `guidelines` (array): Narrow the run to these guideline slugs (e.g. "minify-and-remove-unused-code") or related-check IDs.
- `timeoutMs` (integer): Give up after this many milliseconds. Defaults to 60000.
- `url` (string, required): The page to check, e.g. https://example.com or http://localhost:3000

Output parameters:

- `detail` (string)
- `report` (object): The complete report; present only when detail is "full"
- `summary` (object)

### `list_guidelines` (~120 tokens)

List WSG guidelines

Lists the guidelines in WSG July-2026, optionally filtered by category, testability, or text in the title, slug, or description. Each entry has the slug to pass to get_guideline or to check_url's guidelines, and how many automated checks implement it.

Input parameters:

- `category` (string): Only guidelines in this category
- `query` (string): Case-insensitive text to find in the title, slug, or description, e.g. "media"
- `testability` (string): Only guidelines that can be tested this way

Output parameters:

- `count` (number)
- `guidelines` (array)
- `spec` (object)

### `get_guideline` (~84 tokens)

Get a WSG guideline

Returns one guideline: its description, category, testability, W3C specification link, and how many automated checks implement it. Accepts a slug, or a deprecated numeric ID such as "3.3", which is resolved to its current slug.

Input parameters:

- `id` (string, required): A guideline slug such as "minify-and-remove-unused-code", or a legacy number

Output parameters:

- `guideline` (object)
- `notices` (array): Notes about the request, e.g. a deprecated ID
- `spec` (object)

## Diagnostics

Captured diagnostic sections: Provenance, Dependencies. The full working is on the page: https://verifymcp.io/servers/ivanoats-wsg-check/sustainablewebsites-wsg-check#diagnostics

## Score history

- 2026-10-03: 80
- 2026-10-02: 80
- 2026-10-01: 80
- 2026-09-30: 80
- 2026-09-29: 80
- 2026-09-28: 80
- 2026-09-27: 80
- 2026-09-26: 80

## Common questions

### What is the WSG Check MCP server?

WSG Check is an MCP server listed in the public MCP registry as io.github.ivanoats/wsg-check. Check websites against the W3C Web Sustainability Guidelines and look up the guidelines. This page covers its npm package (@sustainablewebsites/wsg-check).

### Is the WSG Check MCP server safe to use?

WSG Check scores 80 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 3 October 2026. It declares no install or post-install scripts. Its build provenance is signed and verified. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the WSG Check MCP server expose?

WSG Check exposes 3 tools: check_url, list_guidelines, get_guideline. Their descriptions and schemas cost roughly 404 tokens of context every time the server is loaded.

### Is the WSG Check MCP server still maintained?

WSG Check is still listed as active in the MCP registry. We last reached this channel on 3 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

### What licence is the WSG Check MCP server under?

WSG Check declares the Apache-2.0 licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.

## Links

- npm package: https://www.npmjs.com/package/@sustainablewebsites/wsg-check
- Socket report: https://socket.dev/npm/package/@sustainablewebsites/wsg-check
- Repository: https://github.com/ivanoats/wsg-check
- Changelog RSS feed: https://verifymcp.io/servers/ivanoats-wsg-check/sustainablewebsites-wsg-check.xml
- Changelog JSON feed: https://verifymcp.io/servers/ivanoats-wsg-check/sustainablewebsites-wsg-check.json
- HTML version of this page: https://verifymcp.io/servers/ivanoats-wsg-check/sustainablewebsites-wsg-check