testing-seo

testing-seo is a skill for Claude Code, Codex from SunrisesIllNeverSee/agent-universe. It costs 39 tokens per session (587 once invoked), scanned A, original, MIT.

Instructions for checking search-engine optimization changes on signomy.xyz. SEO helps search engines understand and correctly link to website pages.

In plain words
What is it for?
Use them to inspect HTML head tags, test canonical URLs and redirects, check sitemap-related changes, and work around protected preview deployments.
Why use it?
They provide checks for page descriptions, canonical links, sitemaps, redirects, and deployment differences so changes can be verified before or after release.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

Good fit Use them to inspect HTML head tags, test canonical URLs and redirects, check sitemap-related changes, and work around protected preview deployments.

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Install with agentmods
npx agentmods add skills/sunrisesillneversee/agent-universe/testing-seo
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add SunrisesIllNeverSee/agent-universe --skill testing-seo
Clone the repo
git clone --depth 1 https://github.com/SunrisesIllNeverSee/agent-universe

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for testing-seo

README.md
[![agentmods](https://agentmods.dev/badge/skills/sunrisesillneversee/agent-universe/testing-seo/github.svg)](https://agentmods.dev/skills/sunrisesillneversee/agent-universe/testing-seo)
Your own site
<a href="https://agentmods.dev/skills/sunrisesillneversee/agent-universe/testing-seo"><img src="https://agentmods.dev/badge/skills/sunrisesillneversee/agent-universe/testing-seo/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for testing-seo

Your own site · 80×15
<a href="https://agentmods.dev/skills/sunrisesillneversee/agent-universe/testing-seo"><img src="https://agentmods.dev/badge/skills/sunrisesillneversee/agent-universe/testing-seo.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 39 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 587 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00039 $0.00587
Opus 5 $0.00019 $0.00293
Sonnet 5 $0.00008 $0.00117
Haiku 4.5 $0.00004 $0.00059

Measured 9d ago against content hash c459e9587aae, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

testing-seo scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

- After merge, spot-check production via `curl -s https://signomy.xyz/<page> | grep 'name="description"'`
.agents/skills/testing-seo/SKILL.md · 57 lines

How it starts

The opening of the file, as written. The whole thing — 57 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Testing SEO Changes — signomy.xyz

Architecture

  • Frontend: Vercel (signomy.xyz DNS) — serves static HTML from frontend/ with cleanUrls: true
  • Backend: Railway — only handles /api/*, /mcp, /health, /ws/*, /docs/* via Vercel rewrites
  • Velvet Rope middleware runs on Railway only — does NOT affect Googlebot crawling pages on Vercel

Vercel Preview Limitation

Vercel preview deployments may have deployment protection (SSO) enabled, returning 401. If this happens:

  • Test source files directly via grep/inspection
  • Curl production to establish a baseline (confirm the problem exists today)
  • After merge, spot-check production via curl -s https://signomy.xyz/<page> | grep 'name="description"'

Key Test Commands

Check meta descriptions exist

for f in frontend/*.html; do
  name=$(basename "$f" .html)
  desc=$(grep -oP 'name="description" content="\K[^"]+' "$f" | head -1)
  echo "$name: ${desc:-MISSING}"
done

Check canonicals

for f in frontend/*.html; do
  name=$(basename "$f" .html)
  canonical=$(grep -oP 'rel="canonical" href="\K[^"]+' "$f" | head -1)
  echo "$name: ${canonical:-NO CANONICAL}"
done

Verify redirects on production

curl -sI -o /dev/null -w "%{http_code} %{redirect_url}" "https://signomy.xyz/<path>"

Check robots.txt

curl -s https://signomy.xyz/robots.txt | grep -i sitemap

Common Issues

  • sitemap.html canonical was broken (pointed to /mapsite which 404'd on Vercel). The canonical should match the actual serving URL.
  • sitemap.xml and sitemap-v2.xml were identical duplicates. Keep only one in robots.txt.
  • Pages with og:description but no <meta name="description"> — Google uses the standard meta tag, not OG.
  • www.signomy.xyz redirects with 307 (temporary) instead of 301. This is a Vercel dashboard setting, not configurable in vercel.json.

Devin Secrets Needed

None — SEO testing uses only public curl requests and source file inspection.

Read the full file on GitHub · 57 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 57 lines · 39 tokens per session scan A c459e9587aae

Subscribe to this mod's changes

testing-seo is a skill published in the GitHub repository SunrisesIllNeverSee/agent-universe (1 stars, last pushed yesterday), licensed MIT. It adds 39 tokens to every session and 587 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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