Cygnix SEO MCP server

Cygnix SEO MCP: free SEO tools for Claude, Cursor & any MCP client

5 no-API-key SEO tools that work on your data: paste keywords, a Google Search Console export or your titles, and get clusters, intent, cannibalization fixes, CTR checks and content briefs. Everything is deterministic and runs locally. No accounts, no tracking, and no made-up search volumes.

Built by Cygnix Labs.

Install

Requires Node.js 18+.

Claude Desktop

Edit claudedesktopconfig.json (macOS: ~/Library/Application Support/Claude/, Windows: %APPDATA%\Claude\):

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

Restart Claude Desktop.

Cursor

Settings → MCP → Add new server, or add to ~/.cursor/mcp.json (or .cursor/mcp.json in a project):

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

Claude Code

claude mcp add cygnix-seo -- npx -y cygnix-seo-mcp

Other clients (VS Code, Windsurf, Cline, Zed…)

Any MCP client that supports stdio: command npx, args -y cygnix-seo-mcp.

From source

git clone https://github.com/cygnixlabs-cmd/cygnix-seo-mcp && cd cygnix-seo-mcp
npm install && npm test
node dist/index.js

Example prompts

• "Cluster these 80 keywords and tell me which page each cluster should target:" (paste list)
• "Classify the search intent of these keywords and flag the commercial ones."
• "Here is my GSC export (query + page). Find keyword cannibalization and tell me what to merge."
• "Check the titles and meta descriptions for these 10 URLs against their target keywords."
• "Write a content brief for 'technical seo audit' using these related keywords: …"

Example output (cannibalization)

## [HIGH] "seo audit checklist" (2 pages, #2 page share 38%)
| Page | Clicks | Impr | Avg pos |
| https://site.com/a | 30 | 1000 | 4.2 |
| https://site.com/b | 5 | 600 | 9.1 |
Action: Pick https://site.com/a as canonical target; merge/301 or de-optimize the others...

Getting GSC data: Search Console → Performance → Search results → add the Page dimension alongside Query (or use the Looker Studio / API export) → Export CSV → paste the text.

Honest limits

• Intent and clustering are rule-based/lexical, so treat them as a fast first pass and confirm with the live SERP.
• Title pixel widths are approximations of Google's SERP rendering.
• No tool estimates search volume or difficulty. Use your own data source for that.

Want the full workflow?

These tools are the free starter layer of the Cygnix SEO Toolkit: full agent skills, prompts and sheets for keyword research → briefs → audits → content refresh.

Shortened. The full README is on GitHub.