Theme

Resolved Material 3 design tokens (colour scheme, typography, shapes) plus a back-pointer to which nodes consumed each token.

At a glance


Kind	`compose/theme`
Schema version	1
Modules	`:data-theme-core` (published) · `:data-theme-connector`
Render mode	default
Cost	medium
Token usage	Inline JSON, not yet benchmarked (scales with consuming nodes). See token usage.
Transport	inline
Platforms	Android · Desktop · shared

What it answers

What Material 3 colour scheme was active during this render? Light or dark? Seed colour? Contrast level?
What typography scale resolved for headlineLarge, bodyMedium, etc.?
Which composables actually consumed MaterialTheme.colorScheme.primary — i.e. read the token, not just inherited a LocalContentColor?
Did a theme refactor accidentally break a node’s intended token (e.g. a Surface that now reads surfaceVariant instead of surface)?

What it does NOT answer

It does not opine on Material 3 best practice (don’t use tertiary on a primary-action button) — it tells you what was used; the design intent is on the reviewer.
It does not enumerate tokens declared but unused in the theme — only what was read.

Use cases

Verify a Material You seed-colour change propagated correctly: render under two seeds and diff the resolved schemes.
Catch a stray hard-coded hex that a refactor was supposed to replace with a token reference.
Drive a theme-token inspector panel in the VS Code extension.

Payload shape

ThemePayload, ResolvedThemeTokens, TypographyToken in :data-theme-core.

// compose/theme
{
  "isDark": false,
  "seedColor": "#FF6750A4",
  "contrastLevel": 0.0,
  "colorScheme": {
    "primary": "#FF6750A4",
    "onPrimary": "#FFFFFFFF",
    "surface": "#FFFFFBFE"
    // …
  },
  "typography": [
    { "name": "headlineLarge", "fontFamily": "Roboto",
      "fontWeight": 400, "fontSize": 32, "lineHeight": 40 }
  ],
  "consumers": [
    { "token": "primary", "nodeIds": [12, 14] }
  ]
}

Enabling

Producer runs once the Theme extension is publicly enabled. May require a small re-render to attribute consumers to nodes — the default daemon.dataFetchRerenderBudgetMs = 30000 covers it. CLI / Gradle output: build/compose-previews/data/<id>/compose-theme.json.

Companion products

Wallpaper — compose/wallpaper for the Material You seed → derived scheme upstream of compose/theme.
Layout inspector — layout/inspector to map a nodeId consumer back to source.
Resources — resources/used for R.color.* references that fed the scheme.