Inspector skinning

The Neotoma Inspector ships with a default palette, but operators and embedders can replace the colour palette and brand text (sidebar title, document title, home-link aria-label) at server start via JSON config files — no fork or rebuild required.

Environment variables and precedence

Two environment variables drive skin resolution. When both are set, NEOTOMA_INSPECTOR_SKIN_CONFIG wins:

NEOTOMA_INSPECTOR_SKIN_CONFIG=/abs/path/to/custom.json — load an arbitrary skin JSON from disk. Useful for one-off embedder customisations without creating a named preset. The path must be absolute.
NEOTOMA_INSPECTOR_SKIN=<name> — load a bundled preset from dist/inspector/skins/<name>.json (built from inspector/public/skins/ at compile time). Use this for named, versioned presets shipped with the package.

When neither variable is set, or the configured file is missing or invalid, the Inspector renders the default Neotoma palette unchanged. Invalid skin files do not crash the server — the sanitizer silently falls back to no skin.

Bundled presets

The repository ships one bundled preset:

sample — a deliberately garish magenta/cyan palette intended to verify that skinning took effect. Not for production use.

To add a preset, drop a valid skin JSON file under inspector/public/skins/<name>.json in the Neotoma source tree. The build pipeline copies it to dist/inspector/skins/<name>.json. After that, NEOTOMA_INSPECTOR_SKIN=<name> resolves it at runtime.

Skin JSON shape

{
  "name": "my-brand",            // required: stable slug, used for data-inspector-skin attribute
  "label": "My Brand Skin",      // optional: human-readable label

  "brand": {
    "sidebar_title": "My Brand",        // replaces the sidebar wordmark
    "header_title": "My Brand — Data",  // sets document.title on first paint
    "home_aria_label": "My Brand home"  // replaces the home-link aria-label
  },

  "light": {                     // CSS variable overrides for light mode
    "background": "220 30% 98%",
    "foreground": "220 20% 10%",
    "primary":    "210 90% 45%",
    "sidebar":    "210 60% 92%"
    // ... see sample.json for the full token list
  },

  "dark": {                      // optional: dark-mode overrides; missing tokens inherit defaults
    "background": "220 25% 8%",
    "foreground": "220 100% 95%"
  }
}

See the full token list in sample.json.

All four top-level keys are optional except name. Omitted palette tokens inherit the Inspector's default values. Brand fields that are missing or empty are ignored.

Colour token reference

Each palette token maps to a CSS custom property (e.g. primary → --primary). The light and dark objects accept the same set of tokens:

background — Page and panel background
foreground — Default text colour
card — Card surface
card-foreground — Text on cards
popover — Popover/dropdown surface
popover-foreground — Text in popovers
primary — Primary action colour (buttons, links)
primary-foreground — Text on primary surfaces
secondary — Secondary action colour
secondary-foreground — Text on secondary surfaces
muted — Muted/subtle surface
muted-foreground — Muted text
accent — Accent highlight colour
accent-foreground — Text on accent surfaces
destructive — Destructive/danger colour
destructive-foreground — Text on destructive surfaces
border — Default border colour
input — Input field border
ring — Focus ring colour
sidebar — Sidebar background
sidebar-foreground — Sidebar text
sidebar-accent — Sidebar accent/hover
sidebar-accent-foreground — Text on sidebar accent
sidebar-border — Sidebar border

Sanitization constraints

The frontend sanitizer in inspector/src/lib/inspector_skin.ts validates every token value before applying it. A value is accepted only when it matches the shadcn/Tailwind HSL triplet format:

"<hue> <saturation>% <lightness>%"

Optionally followed by a slash and an alpha component:

"210 90% 45% / 0.8"

Allowed examples:

"220 30% 98%" — hue, saturation%, lightness%
"0 0% 100%" — white
"210 90% 45% / 0.5" — with alpha

Rejected examples:

"#3b82f6" — hex colour (not HSL triplet)
"rgb(59, 130, 246)" — rgb() notation
"hsl(210, 90%, 45%)" — hsl() function syntax (the CSS variable system wraps values, so function syntax is not needed)
Any value containing colons, semicolons, curly braces, or other CSS punctuation that could escape the var() context

Brand string fields (sidebar_title, header_title, home_aria_label) are truncated to 80 characters. Whitespace is trimmed. Empty strings after trimming are ignored.

Unknown token keys in light / dark are silently skipped. A skin that fails name validation (missing, empty, non-string) is rejected entirely and the Inspector falls back to its default palette.

Runtime injection

The server-side loader reads the configured skin file at startup, sanitizes it, and injects it into the SPA HTML shell as:

<script>window.__NEOTOMA_INSPECTOR_SKIN__ = { "name": "…", … };</script>

initialize_inspector_skin_on_load() in inspector/src/lib/inspector_skin.ts runs before the React tree mounts, writing a <style id="neotoma-inspector-skin"> tag with the validated CSS variables and setting data-inspector-skin="<name>" on <html>. This ensures the first paint matches the configured palette — no flash of the default theme.

Local smoke commands

Apply a bundled preset and start the dev server:

NEOTOMA_INSPECTOR_SKIN=sample npm run dev

Apply a custom JSON file from disk:

NEOTOMA_INSPECTOR_SKIN_CONFIG=/abs/path/to/custom.json npm run dev

Verify the skin took effect by opening the Inspector in a browser and checking:

The <html> element has a data-inspector-skin="<name>" attribute.
The <head> contains a <style id="neotoma-inspector-skin"> tag with your token overrides.
The sidebar wordmark and document title match the brand fields you configured (if set).

A quick one-liner using the bundled sample preset:

NEOTOMA_INSPECTOR_SKIN=sample npm run dev &
# Open http://localhost:5175/ — should render a magenta/cyan palette.
# Confirm: document.querySelector('html').dataset.inspectorSkin === 'sample'

See the

changelog

for v0.16.0 release notes covering Inspector skinning (PR #1585), and

Inspector reference

for the full Inspector operator guide.