figma-agent

Local font helper for Figma, Linux and macOS.

A small Rust daemon that exposes the two endpoints the Figma web client calls to enumerate and load locally-installed fonts.

OPTIONS preflight is handled for CORS, including Access-Control-Allow-Private-Network: true, required by Chrome 94+ when figma.com (public origin) reaches 127.0.0.1 (private network).

Responses are gzip/deflate/zstd-compressed when the client sends Accept-Encoding. Server: FigmaAgent/<version> is set on every response. Trailing slashes are normalised (so /font-files/ and /font-files route to the same handler). Matches the orig macOS Figma Agent's middleware stack.

The non-browser endpoints from the official macOS Figma Agent (spell-check, desktop/open-url, clear-data, assets/*, font-preview) are intentionally not implemented; they exist for the Figma desktop app's IPC with macOS system APIs and are not exercised by figma.com itself.

Build

cargo build --release

--release --no-default-features to drop TLS (smaller binary, HTTP-only).

Run

./target/release/figma-agent

Default ports: HTTP 127.0.0.1:44950, HTTPS 127.0.0.1:44951 (same as the macOS Figma Agent).

Config

Optional JSON file at $XDG_CONFIG_HOME/figma-agent/config.json, falling back to ~/.config/figma-agent/config.json on both Linux and macOS.

{
  "host": "127.0.0.1",
  "port": 44950,
  "tls_port": 44951,
  "tls_cert": null,
  "tls_key": null,
  "font_dirs": [
    "/usr/share/fonts",
    { "path": "/Users/me/Library/Fonts", "user_installed": true }
  ]
}

• font_dirs entries can be plain strings (treated as user_installed=false) or detailed objects to override the classification.
• tls_port: null disables HTTPS entirely.
• If tls_cert/tls_key are absent, a self-signed cert is generated for localhost/127.0.0.1 at startup; trust it once on your machine (macOS: security add-trusted-cert; Linux: NSS DB).

Font discovery

Two sources, deduped by absolute path:

1. OS registry: CTFontManagerCopyAvailableFontURLs on macOS, fc-list on Linux. Captures Font Book registrations, Adobe Fonts, fontconfig user dirs, and anything else the system already knows about.
2. font_dirs config: explicit directories you want walked. Entries here override the auto-classification (e.g., mark a system path as user_installed: true if you want).

The parsed catalogue is cached to $XDG_CACHE_HOME/figma-agent/font_cache.json (default ~/.cache/figma-agent/font_cache.json) on Linux and macOS alike. Cache is keyed by daemon version; delete the file or upgrade to force a refresh (e.g., after adding fonts).

Response schema

{
  "version": "0.1.0",
  "modified_at": 1716000000,
  "modified_fonts": [],
  "fonts": [
    {
      "family": "Inter",
      "style": "Regular",
      "postscript": "Inter-Regular",
      "weight": 400.0,
      "stretch": 100.0,
      "italic": false,
      "variationAxes": [
        {
          "tag": "wght",
          "name": "Weight",
          "value": 400.0,
          "min": 100.0,
          "max": 900.0,
          "default": 400.0,
          "hidden": false
        }
      ],
      "user_installed": false,
      "name": "Inter Regular",
      "path": "/usr/share/fonts/Inter-Regular.ttf"
    }
  ],
  "request_id": 1,
  "elapsed_ms": 42
}

This matches the macOS Figma Agent's FontInfo schema 1:1, except for the trailing path field, which we add so the follow-up GET /font-file call has a usable identifier (the orig daemon's client knows the path through other means).

Variable fonts with fvar named-instances expand to one entry per instance (Inter VF becomes Thin, Light, Regular, etc.), matching CoreText's behaviour on the orig macOS agent. The instance's weight / stretch reflect the runtime wght / wdth axis coordinates, and each variationAxes[i].value is the per-instance coordinate rather than the file-level default.

/font-file errors return JSON: { error, detail, version, request_id }. Validation: non-empty, ≤ 4 KB path, absolute, no .. segments, regular file, ≤ 256 MB, and inside one of font_dirs. The 256 MB ceiling is higher than orig's 32 MB so large macOS CJK collections (AppleSDGothicNeo.ttc, PingFang.ttc) remain reachable.

License

MIT, see LICENSE.