ai-text-summariser

ai-text-summariser is a JavaScript wrapper for the browser's Summarizer API, providing streaming and non-streaming AI-powered text summarization in a consistent, developer-friendly way.

Supports:

• Types: headline, key-points, teaser, tldr
• Formats: plain-text, markdown
• Lengths: short, medium, long
• Streaming and non-streaming modes
• Automatic availability check
• Chrome v138+ compatibility check
• Custom progress monitoring and AbortController support

Installation

npm install ai-text-summariser

Requirements

• Browser: Chrome v138 or newer (due to dependency on the built-in Summarizer API introduced in Chrome 138)

• JavaScript environment: Browser context (Node is supported only for testing availability and config validation; summarization will not work in Node without a polyfill).

• Experimental AI APIs enabled (in Chrome flags, depending on your build):

  • chrome://flags/#enable-ai-features
  • chrome://flags/#summarizer-api

Importing

import Summariser from 'ai-text-summariser';
// or
const Summariser = require('ai-text-summariser').default;

Configuration

The constructor accepts a config object:

{
  type?: 'headline' | 'key-points' | 'teaser' | 'tldr'; // default: 'headline'
  format?: 'plain-text' | 'markdown';                   // default: 'plain-text'
  length?: 'short' | 'medium' | 'long';                  // default: 'medium'
  expectedInputLanguages?: string[];                     // default: ['en']
  expectedContextLanguages?: string[];                   // default: ['en']
  outputLanguage?: string;                               // default: 'en'
  streaming?: boolean;                                   // default: false
  sharedContext?: string | null;                         // default: null
  monitor?: (monitorObj: any) => void;                   // optional
  signal?: AbortSignal;                                  // optional
}

Defaults

If you omit a property, the default will be applied automatically.

API Reference

Class: Summariser

constructor(config?: SummariserConfig)

Create a new summariser instance with optional config.

async checkAvailability(): Promise<boolean>

Checks:

• Chrome version (throws error if <138)
• Summarizer API availability for given config

async summarise(text: string, context?: string): Promise<string>

Performs non-streaming summarisation and returns the full result as a string.

async *summariseStream(text: string, context?: string): AsyncIterable<string>

Performs streaming summarisation, yielding chunks as they arrive.

Example Usage

1. Non-streaming headline

import Summariser from 'ai-text-summariser';

(async () => {
  const summariser = new Summariser({
    type: 'headline',
    format: 'plain-text',
    length: 'short'
  });

  if (!(await summariser.checkAvailability())) {
    console.error('Summarizer not available in this browser.');
    return;
  }

  const result = await summariser.summarise(
    'Your long article text goes here...',
    'Story'
  );
  
  console.log('Summary:', result);
})();

2. Streaming key-points

import Summariser from 'ai-text-summariser';

(async () => {
  const summariser = new Summariser({
    type: 'key-points',
    format: 'markdown',
    length: 'long',
    streaming: true,
    monitor(m) {
      m.addEventListener('downloadprogress', (e) => {
        console.log(`Downloaded ${(e.loaded * 100).toFixed(2)}%`);
      });
    }
  });

  if (!(await summariser.checkAvailability())) {
    console.error('Summarizer not available.');
    return;
  }

  let output = '';
  for await (const chunk of summariser.summariseStream(
    'Your long text here...',
    'Article'
  )) {
    output += chunk;
    process.stdout.write(chunk); // live output
  }

  console.log('\nFinal summary:', output);
})();

3. Aborting a request

const abortController = new AbortController();

const summariser = new Summariser({
  type: 'tldr',
  streaming: false,
  signal: abortController.signal
});

setTimeout(() => abortController.abort(), 2000); // cancel after 2s

Availability Check

Before calling summarise or summariseStream, always do:

if (!(await summariser.checkAvailability())) {
  console.error('Summarizer not available for this config.');
  return;
}

If the API is not available, you can:

• Show a fallback UI
• Use a server-based summarisation API
• Ask user to upgrade Chrome to v138+

Error Handling

ai-text-summariser throws descriptive errors for:

• Invalid config: Unsupported type, format, length
• Browser compatibility: Chrome version < 138
• API unavailability: Summarizer API not exposed
• Summarisation failures: Errors from Summarizer.create() or during summarization

Example:

try {
  const result = await summariser.summarise(text);
} catch (err) {
  console.error('Summarisation failed:', err.message);
}

Chrome v138+ Requirement

ai-text-summariser will not work in:

• Older versions of Chrome (<138)
• Non-Chromium browsers (unless they implement Summarizer API)
• Headless Chrome without AI APIs enabled

To check your Chrome version:

1. Go to chrome://version/
2. Ensure "Google Chrome" shows 138.x.x.x or newer.

Further Notes

• For developers: This package assumes a modern JS environment and does not polyfill the Summarizer API.
• For Node.js: You can import and use checkAvailability() and config validation, but summarisation methods require a browser.