cometchat-native-theming

name	cometchat-native-theming
description	CometChatThemeProvider + CometChatI18nProvider — color tokens, typography, dark mode, per-component style overrides, and localization (18 built-in languages + custom translations). The JS theme object replaces CSS variables.
license	MIT
compatibility	Node.js >=18; React Native >=0.70; @cometchat/chat-uikit-react-native ^5
allowed-tools	executeBash, readFile, fileSearch, listDirectory, AskUserQuestion
metadata	{"author":"CometChat","version":"3.0.0","tags":"cometchat react-native theming colors dark-mode typography"}

Purpose

Teaches Claude how to theme and localize the React Native UI Kit via CometChatThemeProvider + CometChatI18nProvider. No CSS — React Native uses a JS theme object instead. This skill covers color tokens, typography, light/dark modes, per-component style overrides, the useTheme() hook for custom views, and localization (18 built-in languages, device auto-detect, custom translation overrides) via useCometChatTranslation().

Read cometchat-native-core first (the wrapper chain that includes CometChatThemeProvider) before this skill. cometchat-native-components § 13 covers per-component style={} overrides, which are a sibling concern to theming.

Ground truth: docs/ui-kit/react-native/theme.mdx, colors.mdx, component-styling.mdx, message-bubble-styling.mdx, and packages/ChatUiKit/src/theme/type.ts (the canonical type definitions).

---

1. How theming works (no CSS — JS theme object)

React Native has no CSS. Instead:

CometChatThemeProvider
  ↓  (provides theme via React Context)
every <CometChat*> component reads theme via internal useTheme()
  ↓
component's default styles merge with theme overrides → rendered styles

The theme object you pass has two top-level keys for light/dark variants:

<CometChatThemeProvider
  theme={{
    mode: "light",      // or "dark", or omit for OS-default
    light: { color: { primary: "#F76808" } },
    dark:  { color: { primary: "#FF8A3D" } },
  }}
>
  <App />
</CometChatThemeProvider>

Style precedence (highest to lowest)

1. Component style={} prop — wins always. Per-component tweak, overrides everything.
2. Custom theme via CometChatThemeProvider — app-wide.
3. Default theme — the UI Kit's built-in palette.

So for a one-off color on a single component, use style={}. For a brand-wide change (primary color everywhere), use the theme.

Deep merge

Theme values are deeply merged with defaults — you only specify what you want to change:

theme={{
  light: {
    color: {
      primary: "#F76808",      // override just primary; everything else keeps defaults
    },
    typography: {
      heading1: { fontWeight: "700" },  // override just heading1 weight
    },
  },
}}

---

2. The CometChatThemeProvider

Minimum setup — follow system light/dark

import { CometChatThemeProvider } from "@cometchat/chat-uikit-react-native";

<CometChatThemeProvider>
  {/* children read the current system mode automatically */}
</CometChatThemeProvider>

Force a mode

<CometChatThemeProvider theme={{ mode: "light" }}>{/* ... */}</CometChatThemeProvider>
<CometChatThemeProvider theme={{ mode: "dark"  }}>{/* ... */}</CometChatThemeProvider>

Placement in the wrapper chain

CometChatThemeProvider is one of the four required wrappers — goes right above CometChatProvider, below SafeAreaProvider (see cometchat-native-core § 3):

<GestureHandlerRootView style={{ flex: 1 }}>
  <SafeAreaProvider>
    <CometChatThemeProvider theme={/* your theme */}>
      <CometChatProvider appId={...} region={...} authKey={...}>
        <YourApp />
      </CometChatProvider>
    </CometChatThemeProvider>
  </SafeAreaProvider>
</GestureHandlerRootView>

Without CometChatThemeProvider, components throw or fall back to minimal styles. Even if you don't customize anything, the wrapper is mandatory.

---

3. Color tokens

Every color is a hex string ("#F76808" — never "rgb(...)" or named colors).

Primary (brand accent)

Token	Controls
primary	Outgoing message bubbles, send button, active tabs, buttons
extendedPrimary50–900	Auto-derived shades of primary. Used for hover, pressed, subtle accents. Only override these if you need finer control — the auto-derivation is usually correct.

Neutrals (surfaces + borders)

Token	Default (light)	Controls
neutral50	#FFFFFF	White/light surface, background1 default
neutral100	#FAFAFA	background2 default
neutral200	#F5F5F5	background3 default
neutral300	#E8E8E8	Incoming bubble default, borders
neutral400	#DCDCDC	Divider lines
neutral500	#A1A1A1	Placeholder / muted text, iconSecondary default
neutral600	#727272	textSecondary (timestamps, subtitles)
neutral700	#5B5B5B	Body text tier 3
neutral800	#434343	Headings default
neutral900	#141414	textPrimary default, iconPrimary default

Background aliases

Token	Maps to (default)	Controls
background1	neutral50	Main app background
background2	neutral100	Sidebars, panels
background3	neutral200	Nested panels, cards
background4	neutral300	Additional surface

Text

Token	Default	Controls
textPrimary	neutral900	Main body text
textSecondary	neutral600	Timestamps, subtitles
textTertiary	neutral500	Hints, placeholders
textHighlight	primary	Links, mentions

Icon

Token	Default	Controls
iconPrimary	neutral900	Active / default icons
iconSecondary	neutral500	Inactive icons
iconHighlight	primary	Action icons

Semantic (state indicators)

Token	Default (light)	Controls
info	#0B7BEA	Info callouts, links
warning	#FFAB00	Warning callouts
success	#09C26F	Online indicator, success messages
error	#F44649	Error messages, validation

Bubble-specific

Token	Default	Controls
sendBubbleBackground	primary	Outgoing bubble bg
sendBubbleText	staticWhite (#FFFFFF)	Outgoing bubble text
receiveBubbleBackground	neutral300	Incoming bubble bg
receiveBubbleText	neutral900	Incoming bubble text

Static (never flip light/dark)

Token	Value	Controls
staticBlack	#141414	Fixed dark elements (overlays, opacity-based)
staticWhite	#FFFFFF	Fixed light elements

---

4. Mode: light / dark / system

Follow system

Don't pass mode — the provider reads the OS setting via useColorScheme() and re-renders on change. The user gets automatic dark mode when they flip the system setting.

<CometChatThemeProvider>{/* ... */}</CometChatThemeProvider>

Force a specific mode

<CometChatThemeProvider theme={{ mode: "dark" }}>{/* ... */}</CometChatThemeProvider>

Toggle controlled by your app

If your app has its own dark-mode switch (stored in user prefs or Redux), drive mode from that state:

const [darkMode, setDarkMode] = useState(false);
// ...
<CometChatThemeProvider theme={{ mode: darkMode ? "dark" : "light" }}>
  <Switch value={darkMode} onValueChange={setDarkMode} />
  <App />
</CometChatThemeProvider>

The provider re-renders children and they pick up the new theme immediately.

Dark-mode palette

Override the dark branch of the theme for a custom dark palette:

<CometChatThemeProvider
  theme={{
    light: { color: { primary: "#6852D6" } },
    dark:  { color: { primary: "#A594F3", background1: "#0B0B0F" } },
  }}
>

---

5. Typography overrides

The theme has a typography block with tokens per role:

<CometChatThemeProvider
  theme={{
    light: {
      typography: {
        heading1: { fontFamily: "Inter-Bold", fontSize: 28, fontWeight: "700" },
        heading2: { fontFamily: "Inter-SemiBold", fontSize: 20 },
        body1: { fontFamily: "Inter-Regular", fontSize: 15 },
        caption1: { fontFamily: "Inter-Regular", fontSize: 12 },
        // ... etc
      },
    },
  }}
>

Common tokens: heading1, heading2, heading3, heading4, body1, body2, caption1, caption2, button1, button2. Each follows the RN TextStyle shape — fontFamily, fontSize, fontWeight, lineHeight, letterSpacing.

Custom font setup

React Native font loading is NOT covered by the UI Kit — use your project's existing font system:

• Expo: useFonts() from expo-font, load before rendering the provider
• Bare RN: add fonts to ios/<App>/Info.plist UIAppFonts + android/app/src/main/assets/fonts/ + run npx react-native-asset

Only reference a fontFamily in the theme once the font is actually loaded — otherwise iOS shows the system default and Android crashes.

---

6. Per-component style blocks

Beyond color / typography, the theme has per-component style blocks for fine control. These sit inside the light / dark branches:

<CometChatThemeProvider
  theme={{
    light: {
      // component-specific overrides
      conversationStyles: {
        containerStyle: { backgroundColor: "#FAFAFA" },
      },
      messageHeaderStyles: {
        titleStyle: { fontSize: 18 },
      },
      messageListStyles: {
        containerStyle: { padding: 8 },
        sendBubbleStyle: {
          backgroundColor: "#F76808",
          textStyle: { color: "#FFFFFF" },
        },
        receiveBubbleStyle: {
          backgroundColor: "#F5F5F5",
          textStyle: { color: "#141414" },
        },
      },
      messageComposerStyles: {
        containerStyle: { backgroundColor: "#FFF", borderTopWidth: 1, borderTopColor: "#E8E8E8" },
      },
    },
  }}
>

Common component-style keys: conversationStyles, usersStyles, groupsStyles, groupMembersStyles, messageHeaderStyles, messageListStyles, messageComposerStyles, threadHeaderStyles, callButtonsStyles, callLogsStyles.

Each block has the same nested shape as the component's style prop (see cometchat-native-components § 13).

Source of truth for available keys

The exact list of style keys per component is authoritative in the kit's type file:

packages/ChatUiKit/src/theme/type.ts

If you're overriding a component style and the TypeScript compiler complains about an unknown key, check that file (or use useTheme() + autocomplete in your IDE).

---

7. Common recipes

Match a brand color (most common)

<CometChatThemeProvider
  theme={{ light: { color: { primary: "#FF6B35" } } }}
>
  <App />
</CometChatThemeProvider>

This single line changes the outgoing message bubble color, send button color, active tab indicator, and every primary accent in the UI. The extendedPrimary50–900 tints are auto-derived from primary.

Dark mode + custom brand

<CometChatThemeProvider
  theme={{
    light: { color: { primary: "#FF6B35" } },
    dark:  { color: { primary: "#FF8F66", background1: "#1A1A1A" } },
  }}
>
  <App />
</CometChatThemeProvider>

Custom message-bubble colors

<CometChatThemeProvider
  theme={{
    light: {
      color: {
        sendBubbleBackground: "#FF6B35",
        sendBubbleText: "#FFFFFF",
        receiveBubbleBackground: "#F0F0F0",
        receiveBubbleText: "#1A1A1A",
      },
    },
  }}
>

Overriding the bubble tokens directly is cleaner than doing it via messageListStyles.sendBubbleStyle — the tokens apply consistently everywhere bubbles render (main list + thread panel + search results).

Custom font across the whole UI

1. Load font (Expo useFonts or bare npx react-native-asset)
2. Override the typography block:

<CometChatThemeProvider
  theme={{
    light: {
      typography: {
        heading1: { fontFamily: "Inter-Bold" },
        heading2: { fontFamily: "Inter-SemiBold" },
        heading3: { fontFamily: "Inter-SemiBold" },
        heading4: { fontFamily: "Inter-Medium" },
        body1: { fontFamily: "Inter-Regular" },
        body2: { fontFamily: "Inter-Regular" },
        caption1: { fontFamily: "Inter-Regular" },
        caption2: { fontFamily: "Inter-Regular" },
        button1: { fontFamily: "Inter-SemiBold" },
        button2: { fontFamily: "Inter-Medium" },
      },
    },
  }}
>

---

8. Reading the theme in custom views

When you write a custom slot view (e.g. a TitleView on CometChatMessageHeader) and want your custom component to match the theme, use the useTheme() hook:

import { useTheme } from "@cometchat/chat-uikit-react-native";

function CustomTitle({ user }: any) {
  const theme = useTheme();
  return (
    <Text style={{
      color: theme.color.textPrimary,
      fontFamily: theme.typography.heading3.fontFamily,
      fontSize: theme.typography.heading3.fontSize,
    }}>
      {user.getName()}
    </Text>
  );
}

// Wire into a header:
<CometChatMessageHeader user={selectedUser} TitleView={(user) => <CustomTitle user={user} />} />

This is how you write custom views that automatically follow dark mode — by reading tokens from useTheme() instead of hardcoding colors.

---

9. Localization — CometChatI18nProvider

Theming and localization are separate concerns but ship together. If your users aren't all English-speaking, wire CometChatI18nProvider alongside CometChatThemeProvider. Every string rendered by the UI Kit (message-action labels, empty states, system messages, alerts) flows through the i18n layer.

9a. Built-in locales

The UI Kit ships translations for 18 languages out of the box:

de, en, es, fr, hi, hu, it, ja, ko, lt, ms, nl, pt, ru, sv, tr, zh, zh-tw

9b. Wrapper chain with i18n — five wrappers, not four

CometChatI18nProvider goes above CometChatThemeProvider (theme is a child of i18n, not the other way around):

import { CometChatI18nProvider, CometChatThemeProvider } from "@cometchat/chat-uikit-react-native";
import { GestureHandlerRootView } from "react-native-gesture-handler";
import { SafeAreaProvider } from "react-native-safe-area-context";

<GestureHandlerRootView style={{ flex: 1 }}>
  <SafeAreaProvider>
    <CometChatI18nProvider>
      <CometChatThemeProvider>
        <CometChatProvider>
          <YourApp />
        </CometChatProvider>
      </CometChatThemeProvider>
    </CometChatI18nProvider>
  </SafeAreaProvider>
</GestureHandlerRootView>

9c. Auto-detect (default)

With no props, CometChatI18nProvider reads the device locale via react-native-localize and picks the matching language if available, falling back to English. No setup needed beyond the wrapper.

Install react-native-localize (required peer dep for auto-detect):

npx expo install react-native-localize     # Expo managed
# or
npm install react-native-localize && cd ios && pod install && cd ..   # bare RN

9d. Force a specific language

Override the device default via selectedLanguage:

<CometChatI18nProvider selectedLanguage="ja">

If the user's app has its own language preference (stored in settings / Redux / MMKV), drive selectedLanguage from that state. The provider re-renders children on change so strings update immediately.

9e. Fallback behavior

Chain: selectedLanguage (if set + available) → device language (if autoDetectLanguage=true) → fallbackLanguage (default 'en').

<CometChatI18nProvider
  selectedLanguage={user.preferredLanguage}   // from your app state
  autoDetectLanguage={true}                    // fall back to device language
  fallbackLanguage="en"                        // final fallback
>

If the user's preferred language isn't bundled AND there's no custom translation for it, the provider logs a warning and uses the fallback.

9f. Custom translations — override or add languages

Pass a translations object to override specific keys in an existing locale, or add a brand-new locale the UI Kit doesn't ship:

const translations = {
  en: {
    // Override a built-in English string
    "NO_MESSAGES_YET": "Say hello to start the conversation!",
    "SENT": "Delivered",
  },
  th: {
    // Add a new language — Thai
    "NO_MESSAGES_YET": "ยังไม่มีข้อความ",
    "SENT": "ส่งแล้ว",
    // ...provide the full key set
  },
};

<CometChatI18nProvider selectedLanguage="th" translations={translations}>

The translation schema is a flat { KEY: "string" } map. Keys are screaming-snake-case (NO_MESSAGES_YET, MESSAGE_COMPOSER_MENTION_ALL, TRANSLATE, etc.). Full key list lives at packages/ChatUiKit/src/shared/resources/CometChatLocalizeNew/resources/en/translation.json in the UI Kit source — grep for "KEY": there to find the exact key for a string you want to override.

9g. Reading the language inside custom views

When you write a custom slot view and need the current language (or want to translate your own strings using the same key set), use the useCometChatTranslation hook:

import { useCometChatTranslation } from "@cometchat/chat-uikit-react-native";

function CustomEmptyState() {
  const { t, language } = useCometChatTranslation();
  return <Text>{t("NO_MESSAGES_YET")}</Text>;
}

The hook also exposes availableLanguages — useful for building a language-picker UI.

9h. Common pitfall — i18n outside the provider

Calling useCometChatTranslation() from a component rendered OUTSIDE CometChatI18nProvider (common when a custom view mounts at the navigator root instead of inside the chat subtree) logs "useCometChatTranslation used outside provider, using fallback translations" and falls through to English. Check your wrapper chain — i18n must wrap every component that reads translations, which is the whole app tree in practice.

---

10. Anti-patterns

1. Don't pass non-hex colors. "rgb(...)", "rgba(...)", named colors, or hsl(...) will break the kit's internal color math (used to derive extendedPrimary). Use "#RRGGBB" or "#RRGGBBAA" (opacity via alpha).

2. Don't override staticBlack / staticWhite. They're "static" for a reason — used in places where a specific absolute color is needed regardless of theme (overlays, badges on fixed-color avatars). Overriding them breaks visual consistency.

3. Don't override extended primary colors unless you need to. extendedPrimary50–900 are auto-derived from primary. Override them only if the auto-derivation doesn't match your brand's tints — and then override the full range, not just one level.

4. Don't wrap CometChatThemeProvider inside a screen. It belongs at the app root, once. Re-wrapping per screen creates hydration-like flashes on navigation and breaks dark-mode switching.

5. Don't mix theme overrides and per-component style={} for the same property. style={} wins — the theme override becomes dead code. Pick one: theme for app-wide, style={} for one-offs.

6. Don't reference an unloaded font in typography. iOS silently falls back to system default; Android crashes. Gate the provider on font loading:

   // Expo example
   const [fontsLoaded] = useFonts({ "Inter-Bold": require("./assets/Inter-Bold.ttf") });
   if (!fontsLoaded) return null;
   return (
     <CometChatThemeProvider theme={{ light: { typography: { heading1: { fontFamily: "" } } } }}>
       
     
   );
   

---

11. Verifying a theme change

After changing the theme:

1. Hard-reload the Metro bundler (not Fast Refresh — theme context sometimes doesn't update on Fast Refresh)
2. Send a message — check the outgoing bubble color matches primary / sendBubbleBackground
3. Toggle dark mode on the device (iOS: Settings → Display; Android: Settings → Display → Dark theme)
4. Check that both modes render without reloading the app

If something looks unstyled or crashes:

• Check the color is a hex string (not a name or rgb)
• Check the font (if you overrode typography) is actually loaded
• Check the override key matches the type in packages/ChatUiKit/src/theme/type.ts

---

Skill routing reference

Skill	When to route
cometchat-native-core	Always read first — init/login/provider wrapper chain
cometchat-native-components	For per-component style={} prop (sibling concern to theming)
cometchat-native-placement	Where CometChat components go
cometchat-native-theming	This skill — app-wide color/typography/dark mode
cometchat-native-customization	Custom slot views + useTheme() in your own components
cometchat-native-expo-patterns	Expo font loading via expo-font
cometchat-native-bare-patterns	Bare RN font loading via react-native-asset
cometchat-native-troubleshooting	Colors not applying, dark mode not switching, font shows system default