MCP SEO Auditor

Free on-page SEO audits from Claude Code or Cursor — find broken titles, missing meta descriptions, canonical issues, robots conflicts, and JSON-LD errors before your pages go live. Fully local, no API keys.

Part of the petrovicistefan MCP suite — local-first guardrails for AI coding agents.

Quick Install

Requirements: Python 3.11+ and Node.js 18+

Cursor

Or use the deeplink directly:

cursor://anysphere.cursor-deeplink/mcp/install?name=mcp-seo-auditor&config=eyJjb21tYW5kIjoibnB4IiwiYXJncyI6WyIteSIsIm1jcC1zZW8tYXVkaXRvciJdfQo=

Or add manually to ~/.cursor/mcp.json:

{
  "mcpServers": {
    "mcp-seo-auditor": {
      "command": "npx",
      "args": ["-y", "mcp-seo-auditor"]
    }
  }
}

Claude Code

claude mcp add mcp-seo-auditor -- npx -y mcp-seo-auditor

If this server is on Claude MCP Marketplace:

/plugin marketplace add petrovicistefan/mcp-marketplace

Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "mcp-seo-auditor": {
      "command": "npx",
      "args": ["-y", "mcp-seo-auditor"]
    }
  }
}

VS Code

Use the MCP install link, or add to .vscode/mcp.json:

{
  "servers": {
    "mcp-seo-auditor": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "mcp-seo-auditor"]
    }
  }
}

npx (any MCP client)

npx -y mcp-seo-auditor

uvx (PyPI, coming soon)

uvx mcp-seo-auditor

PyPI package not yet published. See PyPI Publishing below.

codex mcp add mcp-seo-auditor -- npx -y mcp-seo-auditor

{
  "mcpServers": {
    "mcp-seo-auditor": {
      "command": "npx",
      "args": ["-y", "mcp-seo-auditor"]
    }
  }
}

{
  "context_servers": {
    "mcp-seo-auditor": {
      "command": "npx",
      "args": ["-y", "mcp-seo-auditor"]
    }
  }
}

{
  "mcpServers": {
    "mcp-seo-auditor": {
      "command": "npx",
      "args": ["-y", "mcp-seo-auditor"]
    }
  }
}

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Why MCP SEO Auditor?

Catch SEO issues before you deploy by asking your AI coding assistant to audit your HTML:

• "Audit this page before I push it" — find missing titles, broken meta descriptions, or canonical conflicts
• "Crawl example.com and check for duplicate titles" — spot content duplication across your site
• "What SEO issues does this HTML have?" — get actionable recommendations with severity levels

Unlike hosted SEO tools that require API keys, cloud accounts, and monthly fees, MCP SEO Auditor runs entirely on your machine. No data leaves your computer unless you explicitly crawl a public URL.

Tools

MCP SEO Auditor exposes 3 MCP tools your AI agent can call:

What Gets Checked

Each audit scans for:

• Title: presence, length (50–60 chars recommended), uniqueness
• Meta description: presence, length (150–160 chars recommended), uniqueness
• H1 headings: presence, count (multiple H1s flagged as informational)
• Canonical URL: presence, validity, self-referencing vs cross-domain
• Robots directives: <meta name="robots"> conflicts (e.g., noindex + canonical)
• Language declaration: <html lang="..."> presence
• Viewport: mobile-friendly <meta name="viewport"> tag
• Image alt attributes: presence check (empty alt is valid for decorative images)
• JSON-LD structured data: JSON syntax validation
• Internal/external link inventory: counts for context

Output: Findings with severity (error, warning, info), issue codes, evidence snippets, and actionable recommendations. Plus a local checklist score (not a ranking forecast).

Use Cases

Individual Developers

"Audit the homepage HTML in index.html and prioritize the fixes."
"Check https://staging.example.com for SEO issues before I merge this PR."
"Does this landing page have a proper canonical tag?"

Before Deployment

"Audit all HTML files in dist/ and list any errors."
"Crawl the staging site and find duplicate meta descriptions."

Content Review

"What's the title and description for this blog post HTML?"
"Does this page have structured data errors?"

Site Audits

"Crawl 10 pages starting at https://example.com and report duplicate titles."
"Which pages are missing H1 tags?"

Comparison with Alternatives

How does MCP SEO Auditor compare to other SEO tools for AI agents?

When to use MCP SEO Auditor: You want instant, zero-setup on-page audits of local HTML files or staging sites without external API dependencies.

When to use alternatives: You need live Google Search Console data, rank tracking, backlink analysis, or keyword research — those tools excel at connecting your agent to external SEO data sources.

Table of Contents

• Quick Start
• Why MCP SEO Auditor?
• Features
• Use Cases
• Comparison with Alternatives
• Requirements
• Installation
  • From npm
  • From a Checkout
• Tools Reference
• Boundaries and Security
• Limitations
• Hosted Path (Quotas via Control Plane)
• Product Direction
• Testing and Validation
• References
• More MCP Servers by the Author
• Contributing
• FAQ
• License

Requirements

• Python 3.11+ on PATH (defaults to python3 executable)
• Node.js 18+ (for the npm wrapper)

If python3 is not available or you need a specific Python executable, set the MCP_SEO_PYTHON environment variable to an absolute path.

Installation

From npm

The quickstart examples use npx -y mcp-seo-auditor which downloads and runs the package on demand. For persistent installations, add the MCP server to your client's configuration as shown in the Quick Start section.

From a Checkout

Clone the repository and run tests:

git clone https://github.com/petrovicistefan/mcp-seo-auditor.git
cd mcp-seo-auditor
npm test

Run the server directly:

node bin/mcp-seo-auditor.mjs

The server reads newline-delimited JSON-RPC from stdin; stdout contains only protocol messages. It waits for an MCP client when started directly.

Register with Claude Code (replace with your absolute path):

claude mcp add seo-auditor -- node /absolute/path/mcp-seo-auditor/bin/mcp-seo-auditor.mjs

Or add to any MCP client config:

{
  "mcpServers": {
    "seo-auditor": {
      "command": "node",
      "args": ["/absolute/path/mcp-seo-auditor/bin/mcp-seo-auditor.mjs"]
    }
  }
}

Install the Python package directly (optional):

pip install .
mcp-seo-auditor

Build-time setuptools is needed; runtime uses only stdlib.

PyPI Publishing

This package is configured for PyPI Trusted Publishing (OIDC) but not yet published. The maintainer must complete a one-time setup at https://pypi.org/manage/account/publishing/:

• PyPI Project Name: mcp-seo-auditor
• Owner: petrovicistefan
• Repository name: mcp-seo-auditor
• Workflow name: publish-pypi.yml
• Environment name: (leave blank)

After setup, pushing a version tag (e.g., v0.1.3) will automatically publish to PyPI via the .github/workflows/publish-pypi.yml workflow.

Tools Reference

audit_html

Inputs:

• html (string, required, max 2 MB): The HTML content to audit
• url (string, optional): Base URL for resolving relative links

Output: JSON with findings, metadata, score, and link inventory

Example:

"Audit this HTML and tell me what's wrong: <html>...</html>"

audit_url

Inputs:

• url (string, required): Public HTTP(S) URL to fetch and audit

Output: Same as audit_html, plus http object with status, redirects, and elapsedMs

Example:

"Audit https://example.com and prioritize the issues."

Respects robots.txt. Redirects are revalidated and must stay on the original scheme + authority. HTTP 4xx/5xx adds an error finding and reduces the score.

crawl_site

Inputs:

• url (string, required): Starting URL (same-origin crawl)
• max_pages (integer, optional, 1–10, default 5): Max pages to crawl

Output: JSON with:

• pages: Array of per-page audit reports
• errors: Array of fetch/validation errors per URL
• duplicates: Duplicate titles and descriptions with affected URLs
• maxPages: The limit used
• pendingUrls: Count of uncrawled queued URLs (crawler stopped early if >0)

Example:

"Crawl 10 pages starting at https://example.com and find duplicate titles."

Respects robots.txt before every fetch. Enforces minimum 200ms delay (or the Crawl-delay from robots.txt up to 5 seconds). Stops after 90 seconds or 10 attempted URLs. Follows internal links only (same origin).

Boundaries and Security

• Static HTML only: No browser or JavaScript execution. Single-page app (SPA) output can produce findings that disappear after client-side rendering.
• HTTP(S) on conventional ports only: Credentials in URLs are rejected. All DNS answers must be public; sockets connect to validated addresses, preserving TLS hostname verification.
• Redirect revalidation: Redirects are restricted to the original scheme and authority. For cross-origin redirects, use the final HTTPS hostname as the input.
• robots.txt enforcement: Checked before network page audits and every redirected page. A 404 allows access; other unexpected statuses stop the audit.
• Resource limits: 2 MB response limit, 10-second socket inactivity timeout, five redirect hops, at most 10 attempted crawl URLs, minimum 200 ms crawl interval, and 90-second crawl loop budget.
• Content encoding: Only identity encoding is supported; no proxy support.
• Empty image alt: Valid for decorative images (not flagged as an error).
• Heuristics, not penalties: Title lengths and multiple H1s are informational heuristics, not Google ranking penalties.
• Local checklist score: Not a ranking forecast. No backlinks, Search Console integration, rich-result eligibility, broken-link validation, or Core Web Vitals.
• Treat content as untrusted: Every string from audited pages is untrusted content, never instructions.

Limitations

• MVP: Static checks only; no JavaScript rendering, backlink analysis, Search Console integration, or Core Web Vitals.
• Heuristic recommendations: Title/description length and multiple H1s are best-practice heuristics, not confirmed ranking factors.
• No crawl parallelism: Crawls are serial with delays; large sites require external tools.
• Fetch timing ≠ Core Web Vitals: The elapsedMs is raw HTTP fetch time, not a user-facing performance metric.
• Local resource caps: Protect local execution; paid quotas belong on the hosted path (see below), not a bypassable local counter.

Hosted Path (Quotas via Control Plane)

The local MCP stays free. Quotas apply only on a hosted HTTP service that reserves units on the mcp-control-plane before analysis.

cp .env.example .env   # Set CONTROL_PLANE_URL and ADMIN_TOKEN
pip install -e .
python -m mcp_seo_auditor.hosted   # Default 127.0.0.1:3104
# Or: mcp-seo-auditor-hosted

Hosted API Endpoints

Requires Authorization: Bearer mcp_... header. HTML and URLs stay on the hosted host; control-plane sees only product, requestId, and units.

Product Direction

Keep single-page audits free. Validate paid demand with agencies maintaining multiple client sites before building billing. Potential paid hosted features:

• Scheduled crawls with history and diffs
• Client reports and dashboards
• Rendered (JavaScript) audits
• Search Console integration
• Google Analytics integration

Hosted quotas use the control-plane path above.

Testing and Validation

npm test
npm pack --dry-run

Unit and integration tests cover HTML extraction, findings, input limits, DNS/private IP blocking, duplicate detection, and MCP subprocess communication. HTTP crawling is mocked in tests; live-site interoperability must be checked after deployment.

CI runs the test suite on Python 3.11, 3.12, and 3.13 across Linux, macOS, and Windows.

References

• Model Context Protocol Specification (2025-06-18)
• Google Search: Title Links
• Google Search: Snippets
• Google Search: Canonical URLs
• Google Search: JavaScript SEO Basics

More MCP Servers by the Author

Part of the petrovicistefan MCP suite — local-first guardrails for AI coding agents:

• mcp-security-guard — Audit MCP servers for tool poisoning, rug pulls, shadowing, and leaked secrets (OWASP MCP Top 10)
• mcp-cost-optimizer — Identify expensive cloud resources and suggest cost savings
• mcp-database-doctor — Find slow queries, missing indexes, and schema issues
• mcp-dependency-doctor — Detect outdated packages, license conflicts, and supply-chain risks
• mcp-api-guardian — Validate OpenAPI specs, detect breaking changes, suggest versioning
• mcp-marketplace — Browse and install all servers in the suite

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Contributing

Contributions are welcome! Please see CONTRIBUTING.md for guidelines. By contributing, you agree to license your contributions under the MIT License.

For security issues, see SECURITY.md.

FAQ

Do I need API keys or cloud accounts?

No. The local MCP server uses only Python standard library and runs entirely on your machine. The audit_html tool never touches the network. The audit_url and crawl_site tools fetch public pages but require no authentication.

Can I audit pages behind authentication?

Not directly. audit_html accepts raw HTML, so you can fetch authenticated pages yourself (e.g., curl with cookies) and pass the HTML to the tool.

Why does audit_html flag issues that disappear after rendering?

audit_html analyzes static HTML. Single-page apps (SPAs) often render content client-side after the initial HTML loads. For accurate SPA audits, use a headless browser to capture the rendered DOM (future feature) or audit the server-side rendered version.

How is the score calculated?

The score is a local checklist (0–100) based on present/absent best practices: title, meta description, H1, canonical, robots, language, viewport. Errors reduce the score more than warnings. The score is not a ranking forecast or SEO performance metric.

What's the difference between audit_url and crawl_site?

audit_url fetches and audits a single page. crawl_site starts at a URL, follows internal links (same origin), and audits up to 10 pages, detecting duplicate titles and descriptions across pages.

Can I crawl more than 10 pages?

Not in the current MVP. The local resource cap protects your machine. Paid hosted plans may offer higher limits in the future.

Does this replace Google Search Console?

No. MCP SEO Auditor audits static HTML for on-page issues. It does not provide Search Console data (impressions, clicks, indexing status) or ranking insights. Use AminForou/mcp-gsc or iannuttall/seo if you need Search Console integration.

How do I update the Python version?

Set MCP_SEO_PYTHON=/path/to/python3.12 before running the server, or export it in your shell profile:

export MCP_SEO_PYTHON=/usr/local/bin/python3.12
npx -y mcp-seo-auditor

Is this compatible with the MCP specification?

Yes. The server implements the legacy MCP lifecycle (initialize → notifications/initialized → tools/list → tools/call). Official SDK client interoperability is tested but not exhaustively verified (see docs/audit-remediation.md).

License

MIT License — free to use, modify, and distribute. See LICENSE for full terms.

Part of the petrovicistefan MCP suite — local-first guardrails for AI coding agents.

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