cate-theme

Authoring Cate Themes

A Cate theme is ONE JSON object that styles the whole IDE:

• app — the window/panel chrome (CSS custom properties: surfaces, text, borders, accents)
• terminal — the xterm palette (background/foreground + the 16 ANSI colors)
• editor — the Monaco code editor (base + syntax token colors)

There is no separate terminal theme any more — one theme colors everything.

The canonical machine-readable schema is theme.schema.json in this skill folder. Validate every theme against it before saving.

Where themes live

User themes are stored in Cate's settings file under the customThemes array, and the active theme is activeThemeId:

macOS:   ~/Library/Application Support/cate/config.json
Linux:   ~/.config/cate/config.json
Windows: %APPDATA%/cate/config.json

Schema

{
  "version": 1,
  "id": "midnight-ember",        // REQUIRED, unique kebab-case slug
  "name": "Midnight Ember",      // REQUIRED, display name
  "type": "dark",                // REQUIRED: "dark" | "light" (drives system light/dark auto-switch + editor base)
  "author": "You",               // optional
  "bootBackground": "#1a1714",   // optional — exact cold-launch window bg (defaults to surface-0)

  "app": {                       // app chrome — see "App colors" below. PARTIAL: omitted keys inherit the base.
    "surface-0": "#1a1714",
    "surface-1": "#221d18",
    "text-primary": "#e7ddd0",
    "text-muted": "#9b9186",
    "border-focus": "#e0683c",
    "focus-blue": "#e0683c",
    "agent-rgb": "224 104 60"
  },

  "terminal": {                  // REQUIRED full xterm palette — ordinary shell output
    "background": "#1a1714", "foreground": "#e7ddd0", "cursor": "#e0683c",
    "selectionBackground": "#3a2f26",
    "black": "#1a1714", "red": "#e0683c", "green": "#8fa86a", "yellow": "#d9a441",
    "blue": "#5f90c4", "magenta": "#b06aa0", "cyan": "#5fa8a8", "white": "#d8cdbf",
    "brightBlack": "#6b6258", "brightRed": "#f0855a", "brightGreen": "#a6c47f",
    "brightYellow": "#e8bd6a", "brightBlue": "#7aa8d6", "brightMagenta": "#c884b8",
    "brightCyan": "#7cc0c0", "brightWhite": "#f4ece1"
  },

  "editor": {                    // REQUIRED Monaco syntax
    "base": "vs-dark",           // "vs" for light themes, "vs-dark" for dark
    "tokens": [                  // syntax rules — foreground is hex WITHOUT the leading #
      { "token": "comment", "foreground": "6b6258", "fontStyle": "italic" },
      { "token": "keyword", "foreground": "e0683c" },
      { "token": "string",  "foreground": "8fa86a" },
      { "token": "constant.numeric", "foreground": "d9a441" },
      { "token": "type",    "foreground": "5f90c4" },
      { "token": "entity.name.function", "foreground": "b06aa0" }
    ],
    "colors": {                  // optional Monaco IColors (# prefixed)
      "editor.background": "#1a1714",
      "editor.foreground": "#e7ddd0"
    }
  }
}