Claude SEO is an open-source Claude Code plugin that runs specialized agents and skills to audit websites across technical SEO, content quality, structured data, AI-search optimization, local and e-commerce SEO, and international SEO. SEO practitioners use it to produce prioritized recommendations based on primary-source guidance, with optional extensions for external data and crawling.
Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add AgriciDaniel/claude-seo/plugin install claude-seoWrote 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.
[](https://agentmods.dev/skills/agricidaniel/claude-seo/seo-cluster)<a href="https://agentmods.dev/skills/agricidaniel/claude-seo/seo-cluster"><img src="https://agentmods.dev/badge/skills/agricidaniel/claude-seo/seo-cluster/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.
<a href="https://agentmods.dev/skills/agricidaniel/claude-seo/seo-cluster"><img src="https://agentmods.dev/badge/skills/agricidaniel/claude-seo/seo-cluster.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk warn
- NVIDIA SkillSpector warn
SkillSpector: 2 findings, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Rogue Agent · line 173 Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.Fix: Remove any persistence mechanisms (cron jobs, startup scripts, state files). Skills should not maintain state across sessions without explicit user consent.
- medium Agent Snooping · line 201 Skill enumerates or reads other installed skills. Access to other skills' SKILL.md files or the skills directory reveals prompt instructions, capabilities, and secrets that should be invisible to peer skills.Fix: Remove all code or instructions that list or read other skills' files or directories. Skills should operate independently; cross-skill access is a privilege escalation.
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00056 | $0.03325 |
| Opus 5.5 | $0.00022 | $0.01330 |
| Sonnet 5.5 | $0.00011 | $0.00665 |
| Haiku 4.5 | $0.00006 | $0.00332 |
Grade A, and why
seo-cluster scanned grade A with 0 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 5d 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.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
Copies of this mod
4 near-identical copies found in the catalogue:
- seo-cluster — 98% identical, 59 lines differ
- seo-cluster — 98% identical, 59 lines differ
- seo-cluster — 97% identical, 102 lines differ
- seo-cluster — 91% identical, 32 lines differ
How it starts
The opening of the file, as written. The whole thing — 332 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Semantic Topic Clustering
SERP-overlap-driven keyword clustering for content architecture. Groups keywords by how Google actually ranks them (shared top-10 results), not by text similarity. Designs hub-and-spoke content clusters with internal link matrices and generates interactive cluster map visualizations.
Scripts: Located at the plugin root scripts/ directory.
Quick Reference
| Command | What it does |
|---|---|
/seo cluster plan <seed-keyword> |
Full planning workflow: expand, cluster, architect, visualize |
/seo cluster plan --from strategy |
Import from existing /seo plan output |
/seo cluster execute |
Execute plan: create content via claude-blog or output briefs |
/seo cluster map |
Regenerate the interactive cluster visualization |
Planning Workflow
Step 1: Seed Keyword Expansion
Expand the seed keyword into 30-50 variants using WebSearch:
- Related searches: Search the seed, extract "related searches" and "people also search for"
- People Also Ask (PAA): Extract all PAA questions from SERP results
- Long-tail modifiers: Append common modifiers: "best", "how to", "vs", "for beginners", "tools", "examples", "guide", "template", "mistakes", "checklist"
- Question mining: Generate who/what/when/where/why/how variants
- Intent modifiers: Add commercial modifiers: "pricing", "review", "alternative", "comparison", "free", "top"
Deduplication: Normalize variants (lowercase, strip articles), remove exact duplicates. Target: 30-50 unique keyword variants. If under 30, run a second expansion pass with the top PAA questions as seeds.
Step 2: SERP Overlap Clustering
This is the core differentiator. Load references/serp-overlap-methodology.md for
the full algorithm.
Process:
- Group keywords by initial intent guess (reduces pairwise comparisons)
- For each candidate pair within a group, WebSearch both keywords
- Count shared URLs in the top 10 organic results (ignore ads, featured snippets, PAA)
- Apply thresholds:
What ships with it
4 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.
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.
- 5d ago Changed · +13 lines · +18 tokens per session 38b754a41a82
- 23d ago Changed 9041eee8c40d
- 28d ago Changed cd79bc1a9281
- 1mo ago Changed · -4 lines · -58 tokens per session 931b18957b0f
- 1mo ago Changed 87ebca8bfc33
- 1mo ago First seen · 323 lines · 96 tokens per session scan A e418337d324d
seo-cluster is a skill published in the GitHub repository AgriciDaniel/claude-seo (22,763 stars, last pushed 5d ago), licensed MIT. It adds 56 tokens to every session and 3,325 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
ads-audit
Run a source-grounded paid-advertising audit for one or more of Google, Meta, YouTube, LinkedIn, TikTok, Microsoft, Apple, Amazon, Reddit, Pinterest, Snapchat, and X. Use for full ad checks, account health reviews, paid-media diagnostics, partial audits after authentication or worker failure, missing-platform…
ads-meta
Audit Meta Ads measurement, Pixel and Events Manager, attribution, Facebook and Instagram creative, audiences, placements, automation, budgets, account structure, and policy. Use for Meta Ads, Facebook Ads, Instagram Ads, Advantage+, Pixel, Events Manager, or Meta account structure. Read-only; use…
ads-microsoft
Audit Microsoft Advertising measurement, UET, search and audience campaigns, Google imports, syndication, keywords, creative, bidding, budgets, Copilot inventory, and policy. Use for Microsoft Ads, Bing Ads, UET, Microsoft Audience Network, or Google Ads import. Read-only; use ads-optimize to change campaigns.
ads-amazon
Audit Amazon Ads profiles, regions, Sponsored Products, Sponsored Brands, Sponsored Display, DSP, portfolios, targeting, search terms, retail readiness, creative, budgets, ACOS, TACOS, reporting, and policy. Use for Amazon Ads, sponsored ads, Amazon PPC, ACOS, TACOS, ASIN advertising, Amazon DSP, or retail-media…
ads-landing
Audit paid-ad landing pages for message match, mobile experience, performance, accessibility, trust, forms, consent, tracking, security, and conversion friction. Use for landing-page audit, post-click experience, LP audit, conversion-rate optimization, form optimization, ad-to-page message match, redirects, blocked…
ads-linkedin
Audit LinkedIn Ads measurement, Insight Tag and conversions, professional audiences, lead generation, ABM, creative, bidding, budgets, pacing, automation, and policy. Use for LinkedIn Ads, Campaign Manager, Insight Tag, Lead Gen Forms, Thought Leader Ads, ABM campaigns, or B2B paid media.