Three words get used as if they meant the same thing, and a Claude Code setup needs all three to stay apart. A skill is a file of instructions. A plugin is a package you install. An MCP server is a program that answers over a protocol, and it can be running on hardware you will never see. This lesson installs nothing on purpose. It names the pieces, says where each one runs and says what each one spends, so the install in lesson 2 is a decision you make instead of a command you copy.
A skill, a plugin and an MCP server are three different things
A skill is a SKILL.md: a Markdown file of instructions your agent loads when they are relevant to what you asked. Nothing executes. The agent reads the file and behaves differently for the rest of the conversation, the way a new teammate behaves differently after reading the house style guide.
A plugin is a package installed into Claude Code. It can carry skills, sub-agents, scripts and slash commands, and installing it writes those files to your disk. claude-seo is a plugin.
An MCP server exposes tools over the Model Context Protocol. Your agent asks it to do something and reads the answer back. The server can sit on your own machine or on somebody else's, behind OAuth, which is where seodraft runs.
The question that separates the three is simple to ask: whose computer does the work, and whose bill does it land on. Answering it for every tool you add is most of what keeps an agent setup understandable six months later.
What claude-seo puts on your machine
claude-seo is a Claude Code plugin with 26 sub-skills and 19 sub-agents, and it lives entirely on your side. The sub-skills cover technical SEO, E-E-A-T, schema, GEO and AI search, local SEO, e-commerce and international work. It is MIT-licensed and public at github.com/AgriciDaniel/claude-seo, which means you can read every instruction before you trust it. The version this course was written against is v2.4.1, read from the project's README on 2026-10-01.
Getting it running takes three commands inside Claude Code:
/plugin marketplace add AgriciDaniel/claude-seo /plugin install claude-seo@agricidaniel-claude-seo /seo setup
The third one does the heavy part. /seo setup creates an isolated Python environment and installs Playwright Chromium into it, which is how the plugin opens a page and looks at what a browser would render. /seo doctor is the command that reports whether that environment still answers, and it is the first thing to run when something stops working.
Python 3.10 or higher is the requirement, and the project recommends 3.11 or higher. The environment is isolated, so the interpreter on your system stays where it is.
API keys are optional throughout. claude-seo works with none at all, and the Google APIs and paid MCP extensions such as DataForSEO or Ahrefs extend it when you have them.
A full audit spends your Claude subscription
Every sub-agent claude-seo starts is a Claude call billed to your account, because the plugin runs locally inside Claude Code and has no model of its own. Five of the judgment-heavy agents run on Opus and the rest run on Sonnet. That split is the reason a full /seo audit costs noticeably more of your subscription than asking one question does, and it is worth knowing before you point it at a 400-page site on a Tuesday morning.
Nothing here is a hidden charge. The spend lands in the same subscription you already watch, and you can see it coming by counting the agents a command starts.
What seodraft keeps on its server
seodraft is a remote MCP server at https://seodraft.app/mcp, reached over OAuth. You register it from your terminal and sign in from inside Claude Code:
claude mcp add --transport http seodraft https://seodraft.app/mcp /mcp
What the server holds is the part that survives a closed terminal: the profile of your business, the evidence bank of things only you know, the topic bank, the editorial calendar and the rules a draft is measured against. It never calls a model. Your own agent writes every word, deterministic rules decide when a draft is done, and you approve it before anything ships.
Keyword data comes from your own DataForSEO account, and the cost of a paid call appears before the call happens. seodraft runs a 7-day trial with no card.
Where the writing happens
The writing happens inside your Claude subscription, in the session you already have open. claude-seo reads your site and tells you what it found. seodraft keeps the plan and checks the draft against the rules. Between them they do the reading, the measuring and the deciding, and the sentences are still yours to put on the page with the agent you pay for.
That is also why neither tool can promise you volume. A harness makes the work checkable. The writing stays as slow as writing.
What to have ready before lesson 2
Three things make the next lesson a five-minute job: a Python 3.10 or higher that answers in the terminal you open Claude Code from, the claude-seo marketplace already on Claude Code's list, and the seodraft MCP server registered. The steps above do all three, and none of them changes a file on your site.
Lesson 2 runs /plugin install, /seo setup and /seo doctor, then signs in to seodraft with /mcp. By the end of it both tools answer, and the course starts looking at your actual pages.