@localmode/chrome-ai

Zero-download, instant AI inference via Chrome's built-in Gemini Nano model. Part of the LocalMode ecosystem.

Features

• Zero model downloads — Gemini Nano ships with Chrome
• Zero bundle size impact — browser-native APIs
• Instant inference — no model loading delay
• Implements SummarizationModel and TranslationModel from @localmode/core
• Automatic fallback support — pair with @localmode/transformers for non-Chrome browsers

Requirements

• Chrome 138+ on desktop (Windows 10+, macOS 13+, Linux, or ChromeOS on Chromebook Plus)
• 22 GB free disk space on the volume containing your Chrome profile (for the Gemini Nano model)
• Hardware: GPU with >4 GB VRAM, or CPU with 16 GB+ RAM and 4+ cores
• Not available on mobile (Android/iOS) or in Incognito mode
• Non-Chrome browsers need a fallback provider (e.g., @localmode/transformers)

Enabling Chrome AI

1. Navigate to chrome://flags/#optimization-guide-on-device-model → set to Enabled
2. Navigate to chrome://flags/#prompt-api-for-gemini-nano → set to Enabled
3. Restart Chrome
4. The Gemini Nano model downloads automatically in the background (~1.5 GB)
5. Verify in DevTools Console: await Summarizer.availability() should return "readily"

For the Summarizer API specifically, also enable chrome://flags/#summarization-api-for-gemini-nano → Enabled with Adaptation for higher-quality summaries via LoRA.

Installation

pnpm add @localmode/chrome-ai @localmode/core

Quick Start

import { summarize, translate } from '@localmode/core';
import { chromeAI } from '@localmode/chrome-ai';

// Summarize text (instant, no download)
const { summary } = await summarize({
  model: chromeAI.summarizer(),
  text: 'Long article text...',
});

// Translate text
const { translation } = await translate({
  model: chromeAI.translator({ targetLanguage: 'de' }),
  text: 'Hello, world!',
});

Fallback Pattern

import { summarize } from '@localmode/core';
import { chromeAI, isSummarizerAPISupported } from '@localmode/chrome-ai';
import { transformers } from '@localmode/transformers';

const model = isSummarizerAPISupported()
  ? chromeAI.summarizer()
  : transformers.summarizer('Xenova/distilbart-cnn-6-6');

const { summary } = await summarize({ model, text: 'Long article...' });

API

chromeAI.summarizer(settings?)

Creates a SummarizationModel using Chrome's Summarizer API.

| Setting | Type | Default | Description | |---------|------|---------|-------------| | type | 'key-points' \| 'tl;dr' \| 'teaser' \| 'headline' | 'tl;dr' | Summary type | | format | 'markdown' \| 'plain-text' | 'plain-text' | Output format | | length | 'short' \| 'medium' \| 'long' | 'medium' | Summary length | | sharedContext | string | — | Context shared across calls |

chromeAI.translator(settings?)

Creates a TranslationModel using Chrome's Translator API.

| Setting | Type | Default | Description | |---------|------|---------|-------------| | sourceLanguage | string | 'en' | Source language (BCP 47) | | targetLanguage | string | 'es' | Target language (BCP 47) |

Feature Detection

import { isChromeAISupported, isSummarizerAPISupported, isTranslatorAPISupported } from '@localmode/chrome-ai';

if (isChromeAISupported()) { /* Chrome AI available */ }
if (isSummarizerAPISupported()) { /* Summarizer API available */ }
if (isTranslatorAPISupported()) { /* Translator API available */ }

Acknowledgments

This package is built on Chrome Built-in AI by Google — on-device AI APIs powered by Gemini Nano, enabling zero-download inference directly in Chrome.

License

MIT