nano-ai-pdf

A TypeScript/JavaScript library that extracts text from PDF files and summarizes them using Chrome’s built‑in on-device Summarizer API (Gemini Nano).

Runs entirely in the browser on supported Chrome versions — no API keys, no servers.

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✨ Features

• 📄 PDF Text Extraction using react-pdftotext
• 🤖 On-device AI Summarization — Chrome’s Summarizer API (Gemini Nano)
• ⏳ Streaming Support — get real-time summary updates
• 🛡️ Runs locally — private & secure
• 🚫 Rejects image-only PDFs
• 📊 Metrics — compression ratio, processing time
• 🖥️ TypeScript typings included
• 📥 Progress tracking — get model download % via functions or callback

📦 Installation

npm install nano-ai-pdf
# or
yarn add nano-ai-pdf

⚙️ Prerequisites

• 🖥 Chrome 138+ (desktop)
• Enable flags:
  • chrome://flags/#prompt-api-for-gemini-nano → Enabled
  • chrome://flags/#optimization-guide-on-device-model → Enabled BypassPerfRequirement
• OS: Windows 10/11, macOS 13+, Linux
• ≥ 22 GB disk space, ≥ 4 GB GPU VRAM
• Must be triggered with user gesture (click, tap, etc.)

📚 API Reference & Examples

1️⃣ summarizePdf(file, options?)

Extracts text from a PDF and returns an AI-generated summary.

import { summarizePdf } from "nano-ai-pdf";

async function runSummarization(file) {
  try {
    const result = await summarizePdf(file, {
      type: "key-points", // 'tldr' | 'headline' | 'teaser'
      format: "markdown", // or 'plain-text'
      length: "medium", // 'short' | 'long'
      context: "Technical report",
    });

    console.log("Summary:", result.summary);
    console.log("Compression:", result.compressionRatio + "%");
  } catch (err) {
    console.error("Error summarizing PDF:", err);
  }
}

Returns:

{
  summary: string;
  originalText: string;
  originalLength: number;
  summaryLength: number;
  compressionRatio: number;
  processingTime: number;
  config: PdfSummarizerOptions;
}

2️⃣ summarizePdfStreaming(file, options?)

Like summarizePdf but yields chunks of the summary as they arrive.

import { summarizePdfStreaming } from "nano-ai-pdf";

async function runStreaming(file) {
  const result = await summarizePdfStreaming(file, {
    type: "tldr",
    format: "plain-text",
    length: "medium",
  });

  let summaryText = "";
  for await (const chunk of result.summaryStream) {
    summaryText += chunk;
    console.log("Chunk:", chunk);
  }

  console.log("Final summary:", summaryText);
}

3️⃣ isSummarizerSupported()

Checks if Chrome’s Summarizer API exists.

import { isSummarizerSupported } from "nano-ai-pdf";

if (!isSummarizerSupported()) {
  console.error("Chrome Summarizer API not supported in this browser.");
}

4️⃣ checkModelAvailability()

Checks if the AI model is ready, needs download, or is unavailable.

import { checkModelAvailability } from "nano-ai-pdf";

(async () => {
  const status = await checkModelAvailability();
  console.log("Model status:", status);
})();

Returns one of: "available" | "downloadable" | "downloading" | "unavailable"

5️⃣ getDownloadProgress()

Returns the last known download % (0-100).

import { getDownloadProgress } from "nano-ai-pdf";

// Polling example
setInterval(() => {
  console.log("Current download progress:", getDownloadProgress() + "%");
}, 500);

6️⃣ onDownloadProgressUpdate(callback)

Registers a callback to receive real-time download updates.

import { onDownloadProgressUpdate } from "nano-ai-pdf";

onDownloadProgressUpdate((progress) => {
  console.log("Progress update:", progress + "%");
});

🚨 Error Handling

Functions throw PdfSummarizerError with a .code property.

| Code | Meaning | | :--------------------------- | :------------------------------ | | NO_FILE | No file provided | | INVALID_FILE_TYPE | File is not PDF | | FILE_TOO_LARGE | Exceeds allowed size | | EMPTY_FILE | File has zero bytes | | EXTRACTION_FAILED | Text extraction failed | | INSUFFICIENT_TEXT | Not enough text content | | API_NOT_SUPPORTED | API not available | | USER_ACTIVATION_REQUIRED | Not called from a user gesture | | MODEL_UNAVAILABLE | AI model unavailable | | SUMMARIZER_CREATION_FAILED | Summarizer could not be created | | SUMMARIZATION_FAILED | Summary generation failed |

🖥 Example Minimal React App

import { useState } from "react";
import {
  summarizePdf,
  isSummarizerSupported,
  checkModelAvailability,
  onDownloadProgressUpdate,
} from "nano-ai-pdf";

export default function App() {
  const [summary, setSummary] = useState("");
  const [progress, setProgress] = useState(0);

  onDownloadProgressUpdate((p) => setProgress(p));

  const handleClick = async (e) => {
    e.preventDefault();

    if (!isSummarizerSupported()) {
      alert("Not supported in this browser!");
      return;
    }

    const availability = await checkModelAvailability();
    if (availability === "unavailable") {
      alert("Model unavailable - check Chrome setup.");
      return;
    }

    const file = document.getElementById("file").files[0];
    if (!file) return alert("Pick a PDF first");

    const result = await summarizePdf(file, { type: "tldr" });
    setSummary(result.summary);
  };

  return (
    <div>
      <input id="file" type="file" accept="application/pdf" />
      <button onClick={handleClick}>Summarize PDF</button>
      <p>Download Progress: {progress}%</p>
      <pre>{summary}</pre>
    </div>
  );
}