@polyglot/react

AI-powered automatic translation library for React applications with intelligent caching and zero-maintenance workflow.

🤔 Why Not Just Use Chrome's Built-in Translator?

Chrome's translator is great for casual browsing, but your library provides enterprise-grade i18n that browser translation can't match:

Control & Consistency

• Chrome: Translates everything inconsistently, breaks layouts, translates technical terms/IDs
• Your Lib: Only translates what you specify, preserves UI structure, skips technical content

Professional Quality

• Chrome: Free but lower quality, inconsistent across browsers (Safari/Firefox differ)
• Your Lib: Professional APIs (DeepL, Google Cloud) with superior accuracy and context

SEO & Accessibility

• Chrome: Client-side only, search engines see original language
• Your Lib: Pre-rendered translations for SEO, proper lang attributes for screen readers

Business Control

• Chrome: User must manually click "Translate"
• Your Lib: Automatic language detection, saved preferences, built-in UI selector

Brand Protection

• Chrome: Can mistranslate brand names, legal terms, product names
• Your Lib: Whitelist/blacklist terms, custom translations for critical content

User Experience

Chrome: Visit site → See English → Click translate → Page reloads → Broken layout
Your Lib: Visit site → Auto-detect Hindi preference → Show Hindi → Perfect layout

Integration with App Logic

• Chrome: Just translates text
• Your Lib: Locale-aware dates/numbers, currency conversion, RTL layouts, locale sorting

Real-World Example (E-commerce)

Chrome Translator:

• "Add to Cart" → ✓ Translated
• "$99.99" → ✗ Stays in dollars
• "SKU: XYZ-123" → ✗ Might translate SKU
• Layout breaks, forms confused

Your Library:

• "Add to Cart" → ✓ Translated
• "$99.99" → ✓ Converted to ₹8,299
• "SKU: XYZ-123" → ✓ Unchanged
• Perfect layout, proper locale formatting

Target Users: SaaS platforms, e-commerce, dashboards, enterprise apps needing proper multi-language support with full developer control.

🚀 Features

• Single API Call at Startup - All translations fetched once and cached
• Auto-Extract Translatable Text - Build-time plugin scans your code automatically
• Smart Caching - LocalStorage/IndexedDB persistence across sessions
• Zero Maintenance - No manual translation files to manage
• Multiple Translation Providers - Support for Google Translate, DeepL, AWS Translate
• Offline-Ready - Works offline after initial translation load
• Dynamic Language Switching - Change languages on the fly
• Type-Safe - Full TypeScript support
• 90% Cost Reduction - Single batch call vs. per-text translation
• Professional Quality - Enterprise-grade accuracy and context awareness

📦 Installation

npm install @polyglot/react
# or
yarn add @polyglot/react

🔧 Setup

1. Configure Vite Plugin (Auto-Extract Text)

// vite.config.js
import { defineConfig } from "vite";
import react from "@vitejs/plugin-react";
import { extractTranslatableText } from "@polyglot/react/plugin";

export default defineConfig({
  plugins: [
    react(),
    extractTranslatableText({
      include: ["src/**/*.{jsx,tsx}"],
      output: "src/translations/texts.json",
      exclude: ["src/**/*.test.{jsx,tsx}"], // Optional
    }),
  ],
});

2. Initialize Translator in Your App

// src/App.jsx
import { TranslateProvider, createTranslator } from "@polyglot/react";
import textsToTranslate from "./translations/texts.json";

const translator = createTranslator({
  // Source language (your app's default language)
  sourceLang: "en",

  // Target language for translation
  targetLang: "hi", // or 'es', 'fr', 'de', etc.

  // Translation provider configuration
  provider: "google", // 'google', 'deepl', or 'aws'
  apiKey: import.meta.env.VITE_TRANSLATE_API_KEY,

  // Texts extracted by build plugin
  textToTranslate,

  // Cache settings
  cache: {
    enabled: true,
    storage: "localStorage", // 'localStorage' or 'indexedDB'
    ttl: 7 * 24 * 60 * 60 * 1000, // 7 days in milliseconds
  },

  // Optional: Fallback behavior
  fallbackToOriginal: true,
});

function App() {
  return (
    <TranslateProvider translator={translator}>
      <YourApp />
    </TranslateProvider>
  );
}

export default App;

3. Use Translations in Components

import { useTranslate } from "@polyglot/react";

function Header() {
  const t = useTranslate();

  return (
    <header>
      <h1>{t("Welcome to Our App!")}</h1>
      <button>{t("Get Started")}</button>
    </header>
  );
}

🎯 How It Works

Build Time (Automatic)

1. Vite plugin scans all .jsx/.tsx files
2. Extracts text content from JSX elements
3. Generates texts.json with all translatable strings

Example Generated File:

["Welcome to Our App!", "Get Started", "Login", "Sign Up", "Contact Us"]

Runtime (Your App Loads)

1. Library reads texts.json
2. Makes single batch API call to translation service
3. Caches all translations in browser storage
4. Serves translations instantly from cache

Component Usage

1. Components call t('original text')
2. Library looks up translation in cache
3. Returns translated text or falls back to original

🌍 Dynamic Language Switching

import { useTranslator } from "@polyglot/react";

function LanguageSwitcher() {
  const { changeLanguage, currentLang, isLoading } = useTranslator();

  const handleLanguageChange = async (lang) => {
    await changeLanguage(lang);
  };

  return (
    <select
      value={currentLang}
      onChange={(e) => handleLanguageChange(e.target.value)}
      disabled={isLoading}
    >
      <option value="en">English</option>
      <option value="hi">हिंदी</option>
      <option value="es">Español</option>
      <option value="fr">Français</option>
    </select>
  );
}

🔌 Translation Provider Configuration

Polyglot API (Recommended - Official)

Simple, powerful, and purpose-built for this library:

const translator = createTranslator({
  provider: "polyglot",
  apiKey: "YOUR_POLYGLOT_API_KEY", // Get from https://usepolyglot.dev
  // ... other config
});

Benefits:

• ✅ Built-in caching and monitoring
• ✅ Simple pricing and billing
• ✅ No complex cloud console setup
• ✅ Free tier available

📚 Full Polyglot API Guide →

Google Translate

const translator = createTranslator({
  provider: "google",
  apiKey: "YOUR_GOOGLE_API_KEY",
  // ... other config
});

DeepL (Better Quality)

const translator = createTranslator({
  provider: "deepl",
  apiKey: "YOUR_DEEPL_API_KEY",
  // ... other config
});

AWS Translate

const translator = createTranslator({
  provider: "aws",
  credentials: {
    accessKeyId: "YOUR_ACCESS_KEY",
    secretAccessKey: "YOUR_SECRET_KEY",
    region: "us-east-1",
  },
  // ... other config
});

Custom API (Your Backend)

const translator = createTranslator({
  provider: "custom",
  customAPIOptions: {
    baseUrl: "http://localhost:8080",
    headers: {
      "X-API-Key": "your_api_key",
    },
  },
  // ... other config
});

💾 Caching Strategies

LocalStorage (Default)

• Fast and simple
• ~5-10MB limit
• Best for smaller apps

cache: {
  storage: 'localStorage',
  ttl: 7 * 24 * 60 * 60 * 1000 // 7 days
}

IndexedDB

• Larger storage capacity
• Better for extensive translations
• Asynchronous operations

cache: {
  storage: 'indexedDB',
  ttl: 30 * 24 * 60 * 60 * 1000 // 30 days
}

🛠️ Advanced Usage

Handle Dynamic Content

For user-generated or API content that isn't in your source code:

import { useTranslateDynamic } from "@polyglot/react";

function UserComment({ comment }) {
  const translateDynamic = useTranslateDynamic();
  const [translated, setTranslated] = useState(comment);

  useEffect(() => {
    translateDynamic(comment).then(setTranslated);
  }, [comment]);

  return <p>{translated}</p>;
}

Variables in Translations

function Welcome({ username }) {
  const t = useTranslate();

  return <h1>{t("Welcome, {{name}}!", { name: username })}</h1>;
}

Pluralization

function ItemCount({ count }) {
  const t = useTranslate();

  return <p>{t("{{count}} item", { count, plural: true })}</p>;
  // Output: "1 item" or "5 items" (auto-translated with correct plural form)
}

📊 Performance Considerations

• Initial Load: ~500ms for batch translation (one-time)
• Subsequent Loads: <5ms (served from cache)
• Cache Size: Typically 50-200KB for average apps
• API Costs: Single batch call vs. per-text calls = 90% cost reduction

🔐 Environment Variables

# .env
VITE_TRANSLATE_API_KEY=your_api_key_here
VITE_TRANSLATE_PROVIDER=google
VITE_DEFAULT_LANGUAGE=en

🧪 Testing

Mock translations in tests:

import { MockTranslateProvider } from "@polyglot/react/testing";

test("renders welcome message", () => {
  render(
    <MockTranslateProvider translations={{ Welcome: "स्वागत है" }}>
      <Header />
    </MockTranslateProvider>
  );

  expect(screen.getByText("स्वागत है")).toBeInTheDocument();
});

🎨 Plugin Configuration Options

extractTranslatableText({
  // Files to scan
  include: ["src/**/*.{jsx,tsx}"],

  // Files to ignore
  exclude: ["**/*.test.{jsx,tsx}", "**/node_modules/**"],

  // Output file path
  output: "src/translations/texts.json",

  // Extract from specific JSX patterns
  patterns: {
    jsxText: true, // <div>Text here</div>
    jsxAttribute: ["title", "placeholder", "aria-label"], // <input placeholder="..." />
    stringLiterals: false, // const text = "Hello" (opt-in)
  },

  // Minimum text length to extract
  minLength: 2,

  // Ignore texts matching regex
  ignore: [/^[0-9]+$/, /^[A-Z_]+$/], // Numbers, constants

  // Debug mode
  verbose: true,
});

📝 API Reference

createTranslator(config)

Creates translator instance with configuration.

useTranslate()

Hook to access translation function in components.

useTranslator()

Hook to access translator instance and control methods.

useTranslateDynamic()

Hook for translating dynamic runtime content.

TranslateProvider

Context provider component for app-wide translations.

🤝 Contributing

Contributions welcome! Please read our Contributing Guide.

📄 License

MIT © 2025

🙋 Support

• 📧 Email: support@@polyglot/react.com
• 💬 Discord: Join our community
• 🐛 Issues: GitHub Issues

🗺️ Roadmap

• Support for more translation providers (Microsoft, Yandex)
• CLI tool for managing translations
• React Native support
• Webpack plugin support
• Translation quality feedback system
• Automatic language detection
• Server-side rendering (SSR) support

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Made with ❤️ for developers who hate maintaining translation files