MCP Field Agent

Build your Craft content model by describing it.

MCP Field Agent extends the Craft MCP plugin (required) adding support for content modelling. That means you can use natural language to create, edit and delete fields, entry types and sections within Craft.

What you can ask for

Start from nothing.

Sketch me a recipe site: recipes with ingredients, method steps and a difficulty rating; chefs; cuisines as a structure; and a homepage single.

Start from something you already have.

Here's the JSON our old CMS exports. Model it in Craft, and tell me where the mapping isn't clean.

Match this TypeScript interface as closely as Craft allows.

Reach into a lot of places at once. Every Matrix block type is its own entry type with its own layout, so one sentence here covers a lot of separate visits by hand.

Add an anchor ID field to all nine block types in the page builder.

Make the image field required in every block type that has one, and set it to half width.

Give the caption field different help text, but only inside the gallery block.

Reshape as you learn.

Split body into intro and body across all three post types.

Turn categoryList into an entries field pointing at the new Topics section.

Move the SEO fields into their own tab on every entry type in the blog.

Creating fields, entry types and sections runs straight through, as fast as your assistant can make the calls, and a whole section with its entry types and their fields arrives in one go. Changing or removing something that already exists takes one extra step.

Every destructive change is reported first

Your assistant fetches a report before it alters or removes anything. The report is read-only, lands in your conversation, and returns a one-time code. The tool that makes the change requires that code, so the report is the only route to it.

One report covers one change, so a sweeping request produces an itemised list of what will happen.

You can also ask for a report on its own:

What would I lose if I deleted the hero image field?

It leads with how many entries hold a value for that field, counted once each however many sites you run, then states what Craft does: a type change reinterprets the stored value, and a delete strands values until each entry is next saved.

Getting started

Already running Craft MCP? This is just another plugin alongside it:

composer require wuhhh/craft-mcp-field-agent
php craft plugin/install mcp-field-agent

If you don't already have Craft MCP installed, install that too. Composer fetches it as a dependency; Craft installs it on request:

php craft plugin/install mcp

Order doesn't matter. Craft MCP talks to your editor and this plugin adds tools to it, so both need to be installed before the tools appear.

If your client isn't configured for this site yet:

php craft mcp/install

That command comes from Craft MCP, so it appears once mcp is installed. It writes configuration for Claude Code, Claude Desktop and Cursor. Point any other MCP client at vendor/bin/mcp-server.

Ask "what field types can you create?" to check it's wired up.

Optional and recommended: drop this snippet into your project's CLAUDE.md so your assistant starts out knowing how to use the tools well.

Not seeing the tools?

Availability is decided when the tools register, so anything this install would refuse is absent from the list your assistant sees. Three things decide it.

Start here: allowAdminChanges is off. This is a development tool. Craft refuses schema changes on production installs, so the plugin registers nothing there. This is the most common cause.

Craft MCP may be withholding them. The nine writing tools are flagged dangerous, and over the HTTP transport they need a full-scope token. Both belong to Craft MCP, and its documentation is the place to change them: dangerous tools and token scopes. The reporting tools carry neither restriction, so if you can ask "what would this do?" but not do it, that's where to look.

Writing also requires an admin, and that rule is ours. Craft's control panel makes fields and sections admin-only, so this matches the CMS. It matters most at full scope, which Craft MCP exempts from permission checks on the grounds that it already grants code execution. That leaves a full-scope token minted for a non-admin free to restructure a content model its user cannot touch in the control panel. Over HTTP the check reads the token's user; a local connection has no user and passes.

What it can change

	Create	Report on	Change
Fields	✓	✓	rename, retype, settings, help text, delete
Entry types	✓	✓	add and remove fields, move between tabs, placement, rename, delete
Sections	✓	✓	add and remove entry types, URLs, rename, delete

Sixteen tools, all named field_agent_*. Your assistant discovers them automatically.

Requirements

• Craft CMS 5.10 or newer
• PHP 8.3
• stimmt/craft-mcp 1.4 or newer

More

• Changelog, with the known limitations
• Design notes — why it works this way, and what was left out
• Development — running the tests, if you're working on the plugin itself

Proprietary. See LICENSE.md.