io.github.jakefleming/font-proof-mcp

font-proof-mcp

Create and modify Hellbox documents programmatically. Hellbox (formerly Font Proof) is a macOS app for type designers that generates PDF font proofs and live-reloads them from Glyphs and RoboFont.

This package launches the MCP server that ships inside the Hellbox app bundle. The server lets AI tools create and edit .fontproof documents directly; the app does not need to be running.

Requirements

• macOS 12 or later
• Hellbox installed (the server binary ships inside the app)
• Node.js 18+ (for npx)

Setup

The easiest path is Hellbox's built-in one-click setup: open Hellbox, go to Preferences, then AI Integration, and click the installer for your client. To set it up manually instead:

Claude Code

claude mcp add font-proof -- npx -y font-proof-mcp

Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "font-proof": {
      "command": "npx",
      "args": ["-y", "font-proof-mcp"]
    }
  }
}

Cursor

Add the same command / args pair to ~/.cursor/mcp.json.

If Hellbox is installed somewhere other than /Applications or ~/Applications, set FONT_PROOF_MCP_PATH to the full path of Hellbox.app/Contents/Helpers/font-proof-mcp.

Tools

• Documents: create_proof, create_complete_proof, open_proof, get_proof_info, open_in_app
• Sections: add_section, update_section, delete_section, reorder_sections, duplicate_section, set_section_content_bulk, update_section_settings
• Fonts: add_fonts, remove_fonts, list_system_fonts (variable font axes supported)
• Glyphs 3: list_glyphs_fonts, add_glyphs_fonts

Full documentation: hellbox.com/docs under "MCP Server".

How it works

The MCP server is a Swift binary embedded in the Hellbox app at Contents/Helpers/font-proof-mcp, codesigned with the app and always in sync with the app's document format. This package is a thin launcher: it finds that binary and hands over stdio. No server logic is duplicated here, so the tools you get always match the app version you have installed.

The package keeps the font-proof-mcp name from the app's Font Proof era; the npm name, the server name MCP clients see, and the .fontproof file extension are all stable across the rename.

Hellbox is made by Minim Industries.