govuk-frontend-mcp

An MCP server that exposes GOV.UK Frontend components and GOV.UK Design System patterns and styles as resources.

Note: This is an unofficial, third-party tool and is not affiliated with or endorsed by GOV.UK or the UK Government.

What's covered

Data is pulled from two independent sources, each with its own release cadence:

• Components come from the govuk-frontend npm package.
• Patterns and styles come from the alphagov/govuk-design-system GitHub repository, from the v5 branch by default.

These are separate projects with separate versioning — do not expect a single version number to describe both.

Available resources

• govuk://components — list all components
• govuk://component/{name} — get a specific component (macro signature, options, example)
• govuk://patterns — list all Design System patterns
• govuk://pattern/{name} — get a specific pattern
• govuk://styles — list all Design System styles
• govuk://style/{name} — get a specific style. govuk://style/page-template additionally includes the annotated GOV.UK Frontend Nunjucks page template.

What's not covered

Sass design tokens, component JavaScript behaviours and GOV.UK Service Manual content are out of scope.

Setup

npm install
npm run build

The build step fetches data from both sources and compiles TypeScript, so it must be run before starting the server.

Building against a different version or branch

By default, npm run build uses the govuk-frontend version pinned in package.json and the v5 branch of govuk-design-system. You can override either independently:

npm run build:data -- 6.1.0       # build components from [email protected]
npm run build:patterns -- main    # fetch patterns from the main branch
npm run build:styles -- main      # fetch styles from the main branch

build:data installs the requested version with npm install --no-save --no-package-lock, so your package.json is not modified.

Heads-up: the -- separator before the argument is required. Without it, npm swallows the value and the script never sees it.

MCP client configuration

Add the server to your MCP client's config file (for Claude Desktop this is claude_desktop_config.json; other clients use the same shape):

{
  "mcpServers": {
    "govuk-frontend": {
      "command": "node",
      "args": ["/absolute/path/to/govuk-frontend-mcp/dist/index.js"]
    }
  }
}

Replace the path with the absolute path to dist/index.js in your checkout. Restart your client after saving.

Other commands

npm run dev         # run the server with tsx, no build step
npm run start       # run the compiled server from dist/
npm run typecheck   # type-check src/ and scripts/ without emitting

Licence

This project is licensed under the MIT License - see the LICENSE file for details.

Built with 💻 by Gabriel Guimaraes