FetchTranscript JavaScript/TypeScript SDK

Official TypeScript/JavaScript SDK for the FetchTranscript API — fetch YouTube transcripts, video metadata, channel info, and more.

Installation

npm install fetchtranscript

Quick Start

import { FetchTranscriptClient } from 'fetchtranscript';

const client = new FetchTranscriptClient({ apiKey: 'yt_your_api_key' });

// Get a transcript
const transcript = await client.transcripts.get('dQw4w9WgXcQ');
for (const segment of transcript.segments) {
  console.log(`[${segment.start.toFixed(1)}s] ${segment.text}`);
}

// Get video metadata
const video = await client.videos.getMetadata('dQw4w9WgXcQ');
console.log(video.title);

API Reference

Transcripts

// Get transcript (JSON format with segments)
const transcript = await client.transcripts.get('VIDEO_ID');

// Get transcript in a specific language
const transcript = await client.transcripts.get('VIDEO_ID', { lang: 'es' });

// Get as plain text
const text = await client.transcripts.getText('VIDEO_ID');

// Get as SRT subtitles
const srt = await client.transcripts.getSrt('VIDEO_ID');

// List available languages
const languages = await client.transcripts.listLanguages('VIDEO_ID');

Videos

// Get video metadata
const metadata = await client.videos.getMetadata('VIDEO_ID');

// Get video chapters
const chapters = await client.videos.getChapters('VIDEO_ID');

// Get video comments
const comments = await client.videos.getComments('VIDEO_ID', { limit: 50 });

Channels

// Get channel info
const channel = await client.channels.getInfo('CHANNEL_ID');

// Get channel videos
const videos = await client.channels.getVideos('CHANNEL_ID', { limit: 20 });

// Get all videos with auto-pagination
const allVideos = await client.channels.getAllVideos('CHANNEL_ID');

Search

// Search videos
const results = await client.search.videos('python tutorial', { limit: 10 });

Error Handling

The SDK throws typed exceptions instead of generic errors:

import {
  FetchTranscriptClient,
  VideoNotFoundError,
  InsufficientCreditsError,
  AuthenticationError,
} from 'fetchtranscript';

const client = new FetchTranscriptClient({ apiKey: 'yt_your_api_key' });

try {
  const transcript = await client.transcripts.get('invalid_id');
} catch (error) {
  if (error instanceof VideoNotFoundError) {
    console.log(`Video not found: ${error.message}`);
  } else if (error instanceof InsufficientCreditsError) {
    console.log('Not enough credits');
  } else if (error instanceof AuthenticationError) {
    console.log('Invalid API key');
  }
}

Exception Hierarchy

| Exception | HTTP Status | Description | |-----------|-------------|-------------| | FetchTranscriptError | — | Base exception | | VideoNotFoundError | 404 | Video not found or transcripts disabled | | ChannelNotFoundError | 404 | Channel not found | | InvalidVideoIdError | 400 | Invalid video/channel ID format | | InsufficientCreditsError | 402 | Not enough credits | | AuthenticationError | 401 | Missing or invalid API key | | ServiceUnavailableError | 503 | Upstream service unavailable |

Response Headers

After each request, you can check:

await client.transcripts.get('dQw4w9WgXcQ');
console.log(client.creditsRemaining);    // Remaining API credits
console.log(client.processingTimeMs);    // Processing time in ms

Requirements

• Node.js 18+ (uses native fetch)
• Zero runtime dependencies

License

MIT