Before you start
Claude SEO is a community plugin by Agrici Daniel, not from Anthropic. It needs Claude Code 1.0.33 or newer and Python 3.11 to 3.14. Install it with /plugin marketplace add AgriciDaniel/claude-seo and /plugin install claude-seo@agricidaniel-claude-seo. It works without API keys. A full audit uses more of your Claude plan than a single-page check, because some of its agents run on Opus.
Set it up and check it
Setup creates the plugin's own Python environment and a headless browser without touching the rest of your system. The doctor command checks it and changes nothing.
Say to Claude Code/seo setup
Then run /seo doctor to confirm everything is ready.
Audit the whole site
The audit works out what kind of site you have first, then runs specialist agents in parallel and gives a health score from 0 to 100 with a plan sorted by impact. Its docs list FULL-AUDIT-REPORT.md and ACTION-PLAN.md among the outputs.