MCP server (AI integration)

Hellbox includes a built-in MCP (Model Context Protocol) server that lets AI tools like Claude Code create and modify proofs programmatically.

How It Works

The MCP server (font-proof-mcp) is embedded in the app bundle. It creates and modifies .fontproof files directly; the app doesn’t need to be running. Results can be opened in Hellbox for instant live PDF rendering.

Setup

Claude Code, run this in your terminal:

claude mcp add hellbox /Applications/Hellbox.app/Contents/Helpers/font-proof-mcp

Claude Desktop, add this to your claude_desktop_config.json:

{
  "mcpServers": {
    "hellbox": {
      "command": "/Applications/Hellbox.app/Contents/Helpers/font-proof-mcp"
    }
  }
}

You can also find these snippets in the app under Settings > AI Integration, with a one-click copy button.

Available Tools

Documents: create, open, read metadata, open in app, create a complete proof with fonts and sections in one call.

Sections: add, update, delete, reorder, duplicate, bulk content update, modify all typography settings.

Fonts: add system fonts (with variable font axis support), remove fonts, enumerate installed fonts.

Glyphs: query open Glyphs 3 documents and instances, add Glyphs fonts to proofs.

Export and inspection: export a proof to PDF, render each page to a PNG image for visual inspection (render_proof_pages), and validate layout (validate_proof_layout) to report page dimensions, coverage issues (per section and font, characters that fall back or render tofu), and overflow issues (sections clipped because overflow to multiple pages is off).

Font discovery: find_fonts_for_script lists installed font families that fully cover a given script (japanese, simplified-chinese, traditional-chinese, korean, cjk, hebrew, arabic, thai, devanagari, latin, cyrillic, greek) or an explicit sample of characters, which is handy for multilingual and CJK proofing.

Example Prompts

Once connected, try asking Claude things like: