seo-audit-mcp

An MCP server that gives Claude (or any MCP client) the ability to audit a live website's technical SEO: sitemap coverage, per-page issues, and redirect chains.

Ask in plain language — "audit mortgagecalculatortools.com and tell me which pages Google is never told about" — and the model calls the tools, crawls the site, and answers with specifics.

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The problem it solves

A site's sitemap.xml is how you tell Google which pages exist. When a page is missing from it, nothing errors and nothing warns — the page simply never accumulates impressions. Checking it by hand means diffing a filesystem listing against an XML file, so in practice nobody does it.

Case study: a 25-page gap that turned out to be correct

The first site this was pointed at had 125 HTML files on disk and 100 URLs in its sitemap. A 25-page gap — the kind of finding that gets written up as a bug and assigned to someone.

One sitemap_coverage call surfaced the gap, and one audit_urls call on a sample explained it: every one of the 25 carried <meta name="robots" content="noindex, follow">. They were two deliberately de-indexed content clusters, and the sitemap was exactly right to omit them. Verified against the filesystem afterwards: 25 noindex pages on disk, the same 25 absent from the sitemap, zero noindex pages wrongly included. Perfect consistency.

That is the useful result. A coverage number alone ("125 vs 100") reads as a defect and buys a day of somebody's time; coverage plus per-page noindex status closes the question in a minute. This tool is as valuable for the false alarms it kills as for the real gaps it finds — which is why audit_urls reports noindex per page rather than only counting URLs.

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Tools

Tool	What it does
fetch_sitemap	Fetches sitemap.xml, follows sitemap-index nesting (max depth 3), returns every declared URL, deduped
audit_urls	Crawls URLs concurrently and reports per-page issues: broken status, redirect chains, missing/over-length <title> and meta description, missing or duplicate <h1>, missing canonical, noindex, thin content
sitemap_coverage	Diffs a sitemap against a list of URLs you know exist → what's missing from the sitemap, what's declared but dead
check_redirects	Traces redirect chains, flags multi-hop chains and chains ending in 4xx/5xx — use after a URL-structure change

Every tool returns structured JSON with an issues list per page and an aggregated issue_summary, so the model can reason over counts instead of re-reading raw HTML.

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Install

pip install -e .

Requires Python 3.10+. Dependencies: mcp>=2.0.0, httpx.

Connect it to Claude Code

Add to .mcp.json in your project (or ~/.claude.json for global use):

{
  "mcpServers": {
    "seo-audit": {
      "command": "python",
      "args": ["-m", "seo_audit_mcp"]
    }
  }
}

For Claude Desktop, the same block goes in claude_desktop_config.json.

Then just ask:

Fetch the sitemap for https://example.com/sitemap.xml, audit the first 20 URLs, and summarise the issues by frequency.

Run it directly

python -m seo_audit_mcp        # stdio transport

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Design notes

Three decisions worth calling out, because they are the difference between a demo and something you can point at a client's production site:

Crawling is rate-limited by construction. fetch_many runs behind an asyncio.Semaphore capped at 16 concurrent requests, and every tool clamps its input. A 500-URL sitemap without that ceiling would open 500 sockets at once and read as an attack to the target host. The crawl is a cost the target site pays, so the ceiling is not configurable upward from the tool surface.

No fetch failure aborts a run. fetch_one catches httpx.HTTPError and records it on the returned PageAudit rather than raising. One dead host in a 200-URL crawl degrades one row instead of losing 199 good results.

Parsing is deliberately lenient. Real-world HTML is malformed often enough that a strict parser raising mid-crawl is a liability. The extractors are permissive regexes that return None rather than throw — but with the traps handled: <script> and <style> bodies are stripped before word-counting and heading extraction, so a <h1> inside a JS string literal is not counted as a heading, and relative canonicals are resolved against the page URL.

normalize_url deliberately does not strip trailing slashes: /a and /a/ can be genuinely different pages, and collapsing them would hide duplicate-content problems this tool exists to surface.

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Tests

pip install -e ".[dev]"
pytest

The suite is network-free — HTTP is exercised through httpx.MockTransport, so it runs in CI and on a plane. It covers the parsing edge cases that bite in production: script-embedded headings, namespace-less sitemaps, relative canonicals, sitemap URLs that return a styled HTML 404 with a 200 status, and non-HTML content types being wrongly reported as pages "missing a title".

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License

MIT