Video Transcript Downloader

node_modules
npm-debug.log*
package-lock.json.bak



{
  "name": "video-transcript-downloader",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "video-transcript-downloader",
      "version": "1.0.0",
      "dependencies": {
        "youtube-transcript-plus": "^2.0.0"
      }
    },
    "node_modules/youtube-transcript-plus": {
      "version": "2.0.0",
      "resolved": "https://registry.npmjs.org/youtube-transcript-plus/-/youtube-transcript-plus-2.0.0.tgz",
      "integrity": "sha512-n4nnGVV3ZABnvk/sSF+W51c/+P6I23kLwwhOiYeKLeHOGfpjwCUthhoKgQk9dldJEgHCkbyJpuD3vkbBxWqDHA==",
      "license": "MIT",
      "engines": {
        "node": ">=20.0.0"
      }
    }
  }
}


{
  "name": "video-transcript-downloader",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "dependencies": {
    "youtube-transcript-plus": "^2.0.0"
  }
}


#!/usr/bin/env node
import { spawn } from "node:child_process";
import fs from "node:fs";
import os from "node:os";
import path from "node:path";
import { fileURLToPath } from "node:url";

import { YoutubeTranscript } from "youtube-transcript-plus";

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

function die(message, code = 1) {
  process.stderr.write(String(message).trimEnd() + "\n");
  process.exit(code);
}

function parseArgs(argv) {
  // Tiny no-deps parser.
  // - `--flag` => boolean
  // - `--key value`
  // - `--` => forward remaining args to yt-dlp
  const positional = [];
  const opts = {};
  let i = 0;
  while (i < argv.length) {
    const a = argv[i];
    if (a === "--") {
      opts.extra = argv.slice(i + 1);
      break;
    }
    if (!a.startsWith("--")) {
      positional.push(a);
      i += 1;
      continue;
    }
    const key = a.slice(2);
    const next = argv[i + 1];
    const isValue = next !== undefined && !next.startsWith("--");
    if (!isValue) {
      opts[key] = true;
      i += 1;
      continue;
    }
    if (opts[key] === undefined) opts[key] = next;
    else if (Array.isArray(opts[key])) opts[key].push(next);
    else opts[key] = [opts[key], next];
    i += 2;
  }
  return { positional, opts };
}

function toArray(v) {
  if (v === undefined) return [];
  if (Array.isArray(v)) return v;
  return [v];
}

function which(cmd) {
  // Avoid shelling out to `which`; keep it portable + fast.
  const envPath = process.env.PATH || "";
  const parts = envPath.split(path.delimiter);
  for (const p of parts) {
    const full = path.join(p, cmd);
    if (fs.existsSync(full)) return full;
  }
  return null;
}

function resolveBin(name, fallback) {
  return which(name) || (fallback && fs.existsSync(fallback) ? fallback : null);
}

function run(cmd, args, { cwd } = {}) {
  return new Promise((resolve) => {
    // Capture stdout + stderr to keep yt-dlp’s error context intact.
    const child = spawn(cmd, args, { cwd, stdio: ["ignore", "pipe", "pipe"] });
    let out = "";
    child.stdout.on("data", (d) => (out += d.toString()));
    child.stderr.on("data", (d) => (out += d.toString()));
    child.on("close", (code) => resolve({ code, out }));
  });
}

function isYouTubeUrl(url) {
  return /(^https?:\/\/)?(www\.)?(youtube\.com|youtu\.be)\//i.test(url);
}

function extractYouTubeId(input) {
  if (!input) return null;
  const raw = String(input).trim();
  if (/^[a-zA-Z0-9_-]{11}$/.test(raw)) return raw;
  const m = raw.match(/(?:v=|youtu\.be\/)([a-zA-Z0-9_-]{11})/);
  return m ? m[1] : null;
}

function decodeHtmlEntities(input) {
  if (!input) return input;
  // Some transcripts come back double-encoded (e.g. "&amp;#39;").
  // Decode up to 2 passes; stop once stable.
  let text = input;
  for (let i = 0; i < 2; i++) {
    const decoded = text
      .replace(/&amp;/g, "&")
      .replace(/&lt;/g, "<")
      .replace(/&gt;/g, ">")
      .replace(/&quot;/g, '"')
      .replace(/&apos;/g, "'")
      .replace(/&#(\d+);/g, (_, dec) => String.fromCodePoint(Number(dec)))
      .replace