On-device AI
No cloud

yarn add react-native-gemini-nano

iOS — install pods

cd ios && pod install

Enable New Architecture

# android/gradle.properties
newArchEnabled=true

# ios/Podfile
:new_arch_enabled => true

Summarize long text into bullet points

async function summarize(article: string) {
  const prompt = `Summarize this article in 3 bullet points.
Each bullet point should be one sentence.
Use simple language.

Article:
${article}`;

  return generateText(prompt, {
    temperature: 0.4,
    maxTokens: 200,  // short output = fewer tokens needed
  });
}

// usage
const summary = await summarize(longArticleText);
// → "• React Native 0.75 introduces...
//    • The new architecture improves...
//    • Developers can now..."

Classify user reviews without a cloud API

type Sentiment = 'positive' | 'neutral' | 'negative';

async function getSentiment(review: string): Promise<Sentiment> {
  const prompt = `Classify the sentiment of this review.
Reply with exactly one word: positive, neutral, or negative.

Review: "${review}"`;

  const raw = await generateText(prompt, {
    temperature: 0.0,  // deterministic: same input → same output
    maxTokens: 5,     // we only need one word
  });

  const word = raw.trim().toLowerCase();
  return ['positive','neutral','negative'].includes(word)
    ? word as Sentiment : 'neutral';
}

// usage
const s = await getSentiment('This app crashes every time.');
// → "negative"

Build a simple stateful chatbot

type Message = { role: 'user' | 'assistant'; content: string };

async function chat(history: Message[], userMessage: string) {
  const conversation = history
    .map(m => `${m.role === 'user' ? 'User' : 'Assistant'}: ${m.content}`)
    .join('\n');

  const prompt = `You are a helpful assistant. Keep answers short.

${conversation}
User: ${userMessage}
Assistant:`;

  return (await generateText(prompt, {
    temperature: 0.8,  // higher = more natural-sounding
    maxTokens: 256,
  })).trim();
}

// usage
const history: Message[] = [];
const reply = await chat(history, 'What is React Native?');
history.push({ role: 'user', content: 'What is React Native?' });
history.push({ role: 'assistant', content: reply });