1# zut themes
2
3zut themes are JSON files that override any subset of the built-in
4light/dark TUI theme. Nothing is required: a theme can change one
5color, only the spinner, only syntax highlighting, or all of them.
6Missing values inherit from zut's built-in default for the detected
7terminal background.
8
9## Where themes live
10
11User themes are discovered from:
12
13```text
14$ZUT_HOME/themes/*.json
15```
16
17Open `/settings` and choose **color theme** to switch. Changes are
18saved in `$ZUT_HOME/config.json` and apply immediately. If the selected
19file is deleted later, zut resets the setting to the built-in auto
20(default) theme.
21
22The built-in choices are:
23
24- **auto** — detect the terminal background and use zut's built-in dark or
25  light palette. This remains the default.
26- **inherited (from terminal)** — use the terminal's reported foreground,
27  background, and ANSI palette. When `COLORTERM=truecolor`/`24bit` or
28  `TERM` ends in `-direct`, zut emits truecolor; otherwise it quantizes
29  derived colors to the xterm-256 palette as a best effort. Terminals that
30  do not answer OSC color queries fall back to zut's built-in palette while
31  still using the advertised color depth.
32- **dark** / **light** — use zut's fixed built-in palettes.
33
34The inherited terminal snapshot is captured at startup and reused when the
35setting is changed live; restart zut to pick up terminal palette changes.
36
37All theme color roles use the same terminal-color model. JSON themes may use
38xterm-256 indexes, ANSI SGR colors, or RGB values for any role. On terminals
39that advertise truecolor, zut emits RGB values directly and expands indexed
40values through the xterm palette; otherwise RGB values fall back to the
41nearest xterm-256 color while indexed values remain indexed. ANSI values keep
42their SGR semantics, with standard foreground/background ranges normalized to
43the role where necessary.
44
45## Theme proposals
46
47- **shades of gray (truecolor)** — a neutral grayscale palette for the UI and
48  syntax highlighting, with an xterm-256 fallback when direct color is
49  unavailable.
50
51Theme files bundled with extensions are discovered in-place from loaded
52extension directories:
53
54```text
55$ZUT_HOME/extensions/<extension>/theme.json
56$ZUT_HOME/extensions/<extension>/themes/theme.json
57<project>/.zut/extensions/<extension>/theme.json
58<project>/.zut/extensions/<extension>/themes/theme.json
59```
60
61zut does **not** copy extension themes into `$ZUT_HOME/themes`; extension
62owned themes stay in the extension directory. The settings picker shows
63source info such as `from extension my-theme-extension`.
64
65## Minimal themes
66
67All of these are valid.
68
69Metadata only:
70
71```json
72{
73  "name": "my-theme",
74  "description": "Metadata only; all visuals inherit zut defaults."
75}
76```
77
78One shared color for both light and dark terminals:
79
80```json
81{
82  "name": "pink-accent",
83  "colors": {
84    "accent": 204
85  }
86}
87```
88
89One color per mode:
90
91```json
92{
93  "name": "split-accent",
94  "colors": {
95    "dark": { "accent": 204 },
96    "light": { "accent": 161 }
97  }
98}
99```
100
101Spinner-only:
102
103```json
104{
105  "name": "custom-spinner",
106  "description": "Only changes the busy spinner.",
107  "spinner_frames": ["◢", "◣", "◤", "◥"],
108  "spinner_messages": ["working"],
109  "spinner_interval_ms": 120
110}
111```
112
113Dark-only themes still work on light terminals. If `colors.light` is
114missing, zut applies `colors.dark` overrides on top of the built-in
115light default. The inverse also works.
116
117```json
118{
119  "name": "custom-spinner",
120  "description": "An alternative spinner for zut that only displays a single spinner text.",
121  "colors": {
122    "dark": {
123      "spinner_frames": ["◢", "◣", "◤", "◥"],
124      "spinner_messages": ["working"],
125      "spinner_interval_ms": 120
126    }
127  }
128}
129```
130
131## Full shape
132
133All fields are optional.
134
135```json
136{
137  "name": "my-theme",
138  "description": "Shown in /settings → color theme.",
139  "color_descriptions": {
140    "accent": "Optional documentation for humans. zut ignores this object."
141  },
142  "colors": {
143    "dark": {
144      "fg": 253,
145      "muted": 244,
146      "accent": 111,
147      "background": "#0b1020",
148      "user": 180,
149      "user_bubble_bg": "#42454b",
150      "user_bubble_fg": 248,
151      "assistant": 117,
152      "tool": 114,
153      "tool_out": 245,
154      "error": 203,
155      "warning": 214,
156      "spinner": 183,
157      "selection_bg": 24,
158      "selection_fg": 231,
159      "spinner_frames": ["⠋", "⠙", "⠚", "⠞", "⠖", "⠦", "⠴", "⠲", "⠳", "⠓"],
160      "spinner_messages": ["thinking", "working"],
161      "spinner_interval_ms": 80,
162      "syntax_base_style": "monokai",
163      "syntax": {
164        "keyword": "#81a1c1 bold",
165        "keyword_constant": "#81a1c1",
166        "keyword_declaration": "#81a1c1",
167        "keyword_namespace": "#81a1c1",
168        "keyword_reserved": "#81a1c1 bold",
169        "keyword_type": "#88c0d0",
170        "name_builtin": "#88c0d0",
171        "name_function": "#8fbcbb",
172        "name_class": "#a3be8c bold",
173        "name_decorator": "#b48ead",
174        "literal_string": "#a3be8c",
175        "literal_string_escape": "#bf616a",
176        "literal_number": "#d08770",
177        "comment": "#616e88 italic",
178        "comment_preproc": "#b48ead",
179        "operator": "#eceff4",
180        "punctuation": "#d8dee9",
181        "text": "#e5e9f0"
182      }
183    },
184    "light": {
185      "fg": 236,
186      "muted": 244,
187      "accent": 33
188    }
189  }
190}
191```
192
193You may also put overrides directly at the top level or directly under
194`colors` when they should apply to both modes:
195
196```json
197{
198  "name": "tiny",
199  "accent": 204,
200  "colors": {
201    "spinner_messages": ["shipping"]
202  }
203}
204```
205
206## Color fields
207
208Every color field accepts the following JSON forms:
209
210```json
211254
212"#42454b"
213{ "mode": "256", "index": 254 }
214{ "mode": "ansi", "index": 100 }
215{ "mode": "rgb", "r": 66, "g": 69, "b": 75 }
216```
217
218Numeric values are xterm-256 indexes. ANSI values use SGR codes, with
219standard foreground/background ranges normalized to the role where necessary.
220RGB values are emitted directly when truecolor is advertised and quantized to
221xterm-256 otherwise. The built-in inherited theme additionally resolves
222semantic accents through the terminal's ANSI palette and derives muted and
223selected surfaces from the terminal foreground/background.
224
225- `fg` — default foreground text.
226- `muted` — secondary text, dividers, gutters, inactive hints.
227- `accent` — prompt bar, bullets, links, headings, active markers.
228- `background` — optional full-row TUI background. If missing, zut uses the terminal's existing background. Experimental: terminal background colors can vary by emulator and scrollback behavior; for the most reliable result, change your terminal background color in your terminal settings instead.
229- `user` — user role label color; mostly compatibility.
230- `user_bubble_bg` — background behind user message rows.
231- `user_bubble_fg` — foreground inside user message rows.
232- `assistant` — assistant/zut accent and spinner text.
233- `tool` — tool names, success marks, diff additions.
234- `tool_out` — plain tool-output text.
235- `error` — errors, refused calls, diff deletions.
236- `warning` — warnings and high context-usage state.
237- `spinner` — reserved spinner color slot.
238- `thinkingMax` or `thinking_max` (names retained for compatibility) - status color used when the opt-in `max` reasoning level is active. Missing values inherit the built-in theme color.
239- `selection_bg` — highlighted row background.
240- `selection_fg` — highlighted row foreground.
241
242The same forms apply to `background`, `user_bubble_bg`, and every other
243semantic color field listed above.
244
245## Spinner fields
246
247Spinner settings can appear at top level, under `colors`, or under
248`colors.dark` / `colors.light`.
249
250- `spinner_frames` — list of frame strings. Single-cell glyphs keep
251  status-bar alignment clean.
252- `spinner_messages` — list of messages; zut picks one per turn.
253- `spinner_interval_ms` — frame interval in milliseconds. Missing or
254  invalid falls back to 80ms.
255
256## Syntax fields
257
258Syntax highlighting uses Chroma style entries. Values may include
259attributes after the color, such as `bold`, `italic`, or `underline`.
260
261Supported syntax override keys:
262
263```text
264keyword, keyword_constant, keyword_declaration, keyword_namespace,
265keyword_reserved, keyword_type, name_builtin, name_function,
266name_class, name_decorator, literal_string, literal_string_escape,
267literal_number, comment, comment_preproc, operator, punctuation, text
268```
269
270Example:
271
272```json
273{
274  "colors": {
275    "dark": {
276      "syntax_base_style": "monokai",
277      "syntax": {
278        "keyword": "#f05b8d",
279        "name_function": "#b675f1",
280        "literal_string": "#58c760",
281        "comment": "#a1a1a1 italic"
282      }
283    }
284  }
285}
286```
287
288## Theme-only extensions
289
290An extension can exist only to ship a theme. No slash command,
291subprocess, or executable is required when the extension contains a
292valid theme file.
293
294```text
295$ZUT_HOME/extensions/my-theme-extension/
296├── extension.json
297└── theme.json
298```
299
300`extension.json`:
301
302```json
303{
304  "name": "my-theme-extension",
305  "version": "1.0.0",
306  "description": "Ships a zut color theme",
307  "enabled": true
308}
309```
310
311No `exec` is needed when `theme.json` or `themes/theme.json` exists.
312If `exec` is present, zut treats it as a normal extension too.
313
314## Validate
315
316zut theme files are plain JSON, not JSONC. Validate before installing:
317
318```bash
319python3 -m json.tool theme.json >/dev/null
320```