fontsource-mcp

An MCP stdio server for https://fontsource.org, which packages 2000+ open-source fonts (all of Google Fonts plus extras) as npm modules served from the jsDelivr CDN. It reads the public API and CDN and needs no key.

A subset is a font file cut down to one script, such as latin. A variable font packs a whole weight range into one file and exposes axes such as wght.

Tools

• search_fonts: fuzzy query over id and family, plus AND filters (category, subsets, weights, styles, variable, license, type). Paginated. Rows carry enough to pick a font.
• get_font: subsets, weights, styles, axes, unicode ranges, license, version, npm names, CSS font-family names, page URL, zip URL, and CDN URL templates for one id.
• get_font_css: <link> tags, @import lines, npm install and import lines, the font-family rule, and inlinable @font-face CSS with absolute URLs. variable:true selects the variable package.
• download_font: writes to <dest>/<id>/. Filters by subset, weight, style, and format (woff2, woff, ttf). variable:true fetches <subset>-wght-<style>.woff2. zip:true saves the official zip unextracted.
• index_fonts: facet counts by category, subset, license, type, and variable. With outFile it writes the full catalog JSON to disk.
• get_axis_registry: the variable-font axis registry.

Download location

download_font writes under dest when given, else FONTSOURCE_DOWNLOAD_DIR, else ./fonts in the server's working directory. Under a plugin install that directory is not your project, so set the variable or pass dest. In Claude Code, export it before launching claude. The Claude Desktop extension asks for a folder at install.

Install

Claude Code:

/plugin marketplace add nightious/fontsource-mcp
/plugin install fontsource-mcp@fontsource-mcp

The plugin wires the server through ${CLAUDE_PLUGIN_ROOT} and adds a skill for agents. Needs Node 18+.

Claude Desktop: download fontsource-mcp.mcpb from Releases and open it. The server is one dependency-free dist/index.mjs, so nothing runs npm install.

Manual: run npm install && npm run build, then add to claude_desktop_config.json:

"fontsource": {
  "command": "node",
  "args": ["C:\\path\\to\\fontsource-mcp\\dist\\index.mjs"],
  "env": { "FONTSOURCE_DOWNLOAD_DIR": "C:\\Users\\you\\fonts" }
}

The MSIX build of Claude Desktop keeps that file under %LOCALAPPDATA%\Packages\Claude_pzs8sxrjxfjjc\LocalCache\Roaming\Claude\.

Build and test

dist/index.mjs is the shipped artifact and is committed. After any change under src/, rebuild and commit it.

npm run build       # dist/index.mjs
npm run pack        # build, then fontsource-mcp.mcpb
npm run selftest    # about 20 live requests, ten seconds

A selftest failure means the API shape or CDN file naming changed.

Data sources

• https://api.fontsource.org/v1/{fonts, fonts/:id, variable/:id, axis-registry, download/:id}
• https://cdn.jsdelivr.net/fontsource/fonts/:id[:vf]@latest/<subset>-<weight|axis>-<style>.<ext>
• https://cdn.jsdelivr.net/npm/@fontsource[-variable]/:id@latest/<file>.css

Each font carries its own license (OFL, Apache-2.0, CC0, and others) in the license field.

License

All rights reserved. See LICENSE. The source is public for reading and for pull requests to this repository. It is not open source; do not redistribute it or publish a modified version.