# mcp-web-validator

W3C HTML/CSS Validator and Technical SEO Audit MCP Server for AI coding assistants.

- **Type:** MCP server
- **Trust:** 85/100 (A), scored on the package rubric
- **Verification:** verified (build provenance)
- **Version:** 1.3.3
- **Author:** AKzar1el
- **License:** MIT
- **npm:** mcp-web-validator
- **Endpoints:** streamable-http https://web-validator-mcp.digestseo.com/mcp
- **Source:** https://github.com/AKzar1el/mcp-web-validator
- **Endpoint health:** reachable (last checked 2026-09-20T11:19:30.233Z, 1 sample) — uptime is not a security property and is not part of the trust score
- **Compatible clients:** claude-code, cursor, copilot, chatgpt, gemini (basis: transport)

## Trust

85/100 (A), scored on the package rubric
- Publisher verified: no
- Build provenance: verified attestation
- npm trusted publishing (OIDC): yes
- Install scripts: nothing suspicious found
- Prompt-injection scan: not run
- Obfuscation scan: not run
- Evidence age: 1 day

## Security scan

- **Status:** clean
- **Scanned:** 2026-09-20T11:19:13.863Z
- **Version scanned:** 1.3.3
- **CVEs:** none found by OSV at scan time

## Tools

8 declared. Statically extracted from the shipped source — a floor on the surface, not a census.
- `html.local` — Reads a bounded local HTML file and sends its markup to the W3C Nu HTML Checker. Use only files the user is authorized to share.
- `html.url` — Fetches a bounded public HTTP(S) page, then sends its markup to the W3C Nu HTML Checker. Private, reserved, credentialed, and nonstandard-port destinations are 
- `css.local` — Reads a bounded local CSS file and sends it to the W3C Jigsaw CSS Validator. Use only files the user is authorized to share.
- `seo.metadata` — Analyzes supplied HTML locally for metadata, heading structure, viewport configuration, image alternatives, and Open Graph fields.
- `links.broken` — Resolves and checks up to 25 public HTTP(S) links in supplied HTML. Redirects are reported but not followed, and response bodies are discarded.
- `schema.markup` — Parses JSON-LD blocks in supplied HTML locally and reports empty blocks or JSON syntax errors. It does not validate vocabulary semantics.
- `report.validation` — Combines W3C HTML/CSS validation, local SEO/accessibility checks, JSON-LD syntax checks, and a bounded public-link check into a Markdown and structured report.
- `screenshot.capture` — Renders a local HTML file or HTTP(S) URL in a sandboxed local Chromium browser and writes PNG screenshots to the requested directory. Existing matching files ma

## Install

**Verdict: install** — No blocking findings and no open coverage gaps — safe to install as configured.
**Config** (claude-code):
```json
"{\n  \"mcpServers\": {\n    \"mcp-web-validator\": {\n      \"command\": \"npx\",\n      \"args\": [\n        \"-y\",\n        \"mcp-web-validator\"\n      ]\n    }\n  }\n}"
```

## Blast radius

Contained to extensive — no credential declaration found, from the publisher, the upstream registry, or the README. Known so far: runs locally and hosted; read-only tool surface.
- Floor 17, ceiling 35 (tier: unknown)
- `unknown` means the floor and ceiling land in different bands — not measured enough to name one. It does not mean low.
- This is impact, not likelihood. A high radius is not a defect: a filesystem server is supposed to write files. It is never part of the trust score.

## Machine-readable views of this entry

- Signed JSON: https://forgeregistry.com/api/v1/packages/mcp-web-validator
- Install plan: https://forgeregistry.com/api/v1/packages/mcp-web-validator/install-plan
- Alternatives: https://forgeregistry.com/api/v1/alternatives/mcp-web-validator
- HTML page: https://forgeregistry.com/registry/mcp-web-validator
- MCP: POST https://forgeregistry.com/api/mcp → `forge_get_package` / `forge_install_plan`

## About this document

Generated by Forge (https://forgeregistry.com) — a compact rendering of the same record served, signed, at the JSON URL above. Trust and scan facts are the registry's own measurements; anything Forge did not measure is named as unmeasured rather than omitted.