gsc-lighthouse

gsc-lighthouse is a skill for Claude Code, Codex from NachoLafuente/5050-gtm. It costs 112 tokens per session (1,547 once invoked), scanned C, original, MIT.

A website health report combining Google Search Console data with Lighthouse performance checks. Google Search Console shows how Google indexes and displays a site, while Lighthouse tests pages for issues such as speed.

In plain words
What is it for?
It helps inspect sitemap and indexing status, review recent search traffic, and test the ten pages receiving the most clicks.
Why use it?
It reduces a long list of SEO and performance warnings to the problems that are most likely to matter.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit It helps inspect sitemap and indexing status, review recent search traffic, and test the ten pages receiving the most clicks.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/nacholafuente/5050-gtm/gsc-lighthouse
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 NachoLafuente/5050-gtm --skill gsc-lighthouse
Clone the repo
git clone --depth 1 https://github.com/NachoLafuente/5050-gtm

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 gsc-lighthouse

README.md
[![agentmods](https://agentmods.dev/badge/skills/nacholafuente/5050-gtm/gsc-lighthouse/github.svg)](https://agentmods.dev/skills/nacholafuente/5050-gtm/gsc-lighthouse)
Your own site
<a href="https://agentmods.dev/skills/nacholafuente/5050-gtm/gsc-lighthouse"><img src="https://agentmods.dev/badge/skills/nacholafuente/5050-gtm/gsc-lighthouse/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 gsc-lighthouse

Your own site · 80×15
<a href="https://agentmods.dev/skills/nacholafuente/5050-gtm/gsc-lighthouse"><img src="https://agentmods.dev/badge/skills/nacholafuente/5050-gtm/gsc-lighthouse.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 112 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,547 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 2 findings. 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 $0.00112 $0.01547
Opus 5.5 $0.00045 $0.00619
Sonnet 5.5 $0.00022 $0.00309
Haiku 4.5 $0.00011 $0.00155

Measured 2mo ago against content hash 43046b20fabf, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade C, and why

gsc-lighthouse scanned grade C with 2 findings 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 2mo ago.

The scan reads SKILL.md. This mod also ships 1 executable file (audit.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Reaches for credential fileshighPrivilege escalation

SSH keys, cloud credentials, git-credentials, .npmrc, /etc/shadow: reading these is how a config file becomes a credential leak.

Sign in with the Google Account that owns the GSC property. Credentials are saved to `~/.config/gcloud/application_default_credentials.json` and any Python script using `google.auth.default()` picks them up automatically

Makes network callslowCapability

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

- **TBT spike > 300ms with stable LCP/FCP** → cold-start signature on serverless platforms (Cloud Run, Lambda@Edge). Warm with a curl loop, re-run.
skills/gsc-lighthouse/SKILL.md · 127 lines

How it starts

The opening of the file, as written. The whole thing — 127 lines — stays where its author put it; the contents beside it link to each section on GitHub.

GSC + Lighthouse health check

Pulls Google Search Console (sitemap status, per-URL index coverage, 28-day search analytics) and runs Lighthouse via the PageSpeed Insights API on the top 10 pages by clicks. Produces a single report a non-technical person can read.

The point: most "SEO audit" tools throw a hundred warnings at you. This one tells you what's actually broken, calibrates against false positives, and groups fixes by theme so you can ship a single PR instead of a hundred.

Step 1: Ask the user 2 questions

  1. What's your GSC property? (the verified site in Search Console)

    • sc-domain:example.com, Domain property (covers all subdomains and protocols)
    • https://example.com/, URL-prefix property (one specific protocol + host)
    • If they don't know, link them to https://search.google.com/search-console and ask them to copy the property URL from the sidebar.
  2. Do you have a PAGESPEED_API_KEY configured? (.env or shell env)

    • yes → Lighthouse step runs.
    • no / skip → Lighthouse step is skipped, GSC report still ships. (See README.md "Setup: PSI API key" for the 3-command setup, ~30 seconds.)

That's it. No other config needed.

Step 2: Run the audit

cd skills/gsc-lighthouse
python audit.py --site "sc-domain:example.com"

Add --no-lighthouse to skip the PSI step. Add --top N to audit a different number of pages (default 10).

The script writes a JSON dump to ./out/audit-<date>.json and prints the structured report to stdout.

Step 3: Report

Read audit.py's stdout straight back to the user. Don't reformat unless they ask; the script's output is already structured for direct read.

If the user wants a TL;DR, summarize in this shape:

## GSC + Lighthouse: {today}

Sitemap:        {N URLs, errors/warnings}
Indexing:       {indexed} / {total}
Search (28d):   {clicks}, {±%} vs prior 28d
Lighthouse:     median perf {score}, median LCP {seconds}

Top 3 fixes (impact-ordered):
1. {theme}, {N pages affected}, est. {savings}
2. ...
3. ...

Bottom line: {one sentence}

Read the full file on GitHub · 127 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 2mo ago First seen · 127 lines · 112 tokens per session scan C 43046b20fabf

Subscribe to this mod's changes

gsc-lighthouse is a skill published in the GitHub repository NachoLafuente/5050-gtm (3 stars, last pushed 4mo ago), licensed MIT. It adds 112 tokens to every session and 1,547 once invoked, about $0.0004 per session on Opus 5.5. A static security scan graded it C with 2 findings (reaches for credential files, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Related

gsc-lighthouse compared with skills from other repositories

gsc-lighthouse next to 6 skills from other repositories
ModTypeStarsLast pushLicenceScanTokensWorks with
gsc-lighthouseNachoLafuente/5050-gtmSkill34mo agoMITC112Claude Code, Codex
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