TUI theme JSON

Themes are JSON documents. Built-in presets are embedded into the binary from themes/*.json at build time (same pattern as starter agents), so curl | sh installs and single-binary releases still have the full catalog. arbiter --init also writes them to ~/.arbiter/themes/ for editing. Your config file is ~/.arbiter/tui.json; custom theme documents live in ~/.arbiter/themes/. Set ARBITER_THEMES_DIR to overlay a filesystem tree during development without rebuilding.

Quick start

Pick a built-in preset (default is high-contrast):

{
  "preset": "nord"
}

Or point at a theme file:

{
  "theme_file": "themes/mine.json"
}

Paths in theme_file are relative to ~/.arbiter/ unless absolute (or ~/…).

Create a custom theme

Export a built-in preset as a starting point:

arbiter --export-theme high-contrast > ~/.arbiter/themes/mine.json

Edit colors (#RRGGBB hex). For a variant of an existing theme, add "preset": "nord" and only the keys you want to change; for a standalone theme, export a full file and edit it directly.

Activate it:

{
  "theme_file": "themes/mine.json"
}

Or name the file mine.json and use /theme mine / "preset": "mine" (user themes in ~/.arbiter/themes/).

arbiter --init copies all built-in theme JSON files into ~/.arbiter/themes/ (skipping files you already edited) and writes example.json as an editable copy of the default.

In-session commands

Command	Effect
`/theme`	Browse themes with ↑↓ live preview; Enter selects, Esc cancels.
`/theme list`	Built-in presets + custom themes in `~/.arbiter/themes/`
`/theme <name>`	Switch preset or custom theme; updates `tui.json`
`/theme save <name>`	Write the current look to `~/.arbiter/themes/<name>.json`
`/theme file <path>`	Load a JSON file and set `theme_file` in `tui.json`

JSON schema

Top-level keys:

Key	Purpose
`preset`	Built-in preset name, or basename of `themes/<name>.json`
`theme_file`	Path to a theme JSON file (relative to `~/.arbiter/`)
`bg`	Pane backgrounds: `base`, `panel`, `header`, `scroll`, `status`, `input`, `footer`, `gutter`
`text`	`primary`, `muted`, `subtle`, `inverse`
`accent`	`primary`, `secondary`, `success`, `warning`, `error`, `info`
`border`	`subtle`, `focus`, `gutter`, plus optional `vertical` / `horizontal` strings
`content`	Markdown/scrollback: `heading` (array of 4), `code`, `link`, diff colors, syntax tokens, panel surfaces (`code_bg`, `code_header_bg`, `code_gutter`, `diff_bg_*`, `system_fg`), `agent_palette` (array of 12), …
`layout`	Padding, column breakpoints, vertical rhythm (`block_gap`, `panel_gap`, `prose_paragraph_gap`), chrome density (`chrome_compact_rows`, `scroll_pad_y`, `scroll_gutter_cols`), `show_footer`, `show_history_sidebar`, `mouse`, …
`component`	Prompt/footer strings

Example partial override on a preset (in tui.json or a theme file):

{
  "preset": "high-contrast",
  "accent": { "primary": "#c678dd" },
  "content": {
    "heading": ["#61afef", "#c678dd", "#56b6c2", "#d19a66"]
  },
  "layout": {
    "pane_padding_x": 1,
    "input_padding_x": 2
  }
}

All color values use "#RRGGBB". Settings in tui.json are merged on top of theme_file / preset (useful for small tweaks without duplicating a full theme).