# MCP

> Connect Claude, ChatGPT, Cursor or any MCP client to your site. Agents get your abilities as tools, your design system as context, and prompts that know how to…

Every Lettern site is a [Model Context Protocol](https://modelcontextprotocol.io) server at `/mcp`.

## Connecting

Find your site's address under **Account → Connect an AI agent**. In Claude Code:

```bash
claude mcp add --transport http cms https://your-site.com/mcp
```

Most clients sign in with OAuth: they open a consent screen on your site, you sign in (with two-factor authentication if enabled) and approve. The agent then acts as you, with your permissions. Revoke access any time under **Account → Tokens**.

Clients without OAuth can send a personal access token instead: `Authorization: Bearer cms_…`. Give tokens narrow **scopes** — ability patterns like `entries/*`, or `read` for read-only access.

## What agents get

**Tools** — every ability you may run that is exposed to MCP, named with a dot (`entries.create`, `design.update`). Security-sensitive abilities — creating tokens, changing passwords, managing users and roles — are never offered to agents.

**Resources** — context to plan with: `cms://collections` (content types and their schemas), `cms://site/design` (the design system: tokens, fonts, element styles), `cms://blocks` (how to compose pages, templates and components — the node model, styles, bindings, interactions and animations, with worked examples), `cms://forms`, `cms://navigation`, `cms://languages` and more from plugins.

**Prompts** — the site's skills, ready-made workflows: _Build a page_ from a brief, _Write a blog post_, _Audit the site_ for SEO and GEO problems, and whatever plugins add.

**Instructions** — how to build the Lettern way: read the collections and the design system first, reuse components and templates (`patterns/list`, `templates/list`), style with tokens, give images alt text, publish when done.

## Building with agents

An agent can edit the same block documents as the admin, because the editor works with structured data:

- **Pages** — `entries/create` and `entries/update` with a blocks field, as JSON or as [Block Markdown](https://docs.lettern.org/editing/block-markdown).
- **Templates and components** — the same abilities in the `templates` and `components` collections; `entries/publish` makes them live.
- **The design system** — `design/get`, `design/update`, `design/fonts-import`; custom code with `design/code`.
- **What is possible** — `blocks/types` lists every block, style property, state, data source, animation property and script action; `blocks/icons` searches icons.

Try: _“Build a pricing page with three plans using our card component, animate the cards in one by one, and make the yearly/monthly switch work.”_

## Protocol details

Lettern speaks the current stateless revision of MCP (`2026-07-28`: per-request version, `server/discover`) and answers older clients that `initialize` (`2025-11-25`, `2025-06-18`, `2025-03-26`). OAuth follows the MCP authorization spec: protected resource metadata at `/.well-known/oauth-protected-resource`, authorization server metadata, dynamic client registration and client ID metadata documents, PKCE (S256) only, short-lived access tokens with rotating refresh tokens. Requests are rate limited per token.

**Group:** Agents

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Source: https://docs.lettern.org/agents/mcp