t-youtube-transcript-fetcher

A TypeScript library for fetching transcripts from YouTube videos.

This is an enhanced version of youtube-transcript with added proxy support and improved TypeScript integration.

Features

- Fetch transcripts from YouTube videos using URL or video ID
- Support for multiple languages
- Proxy support with flexible configuration options
- Comprehensive error handling
- TypeScript support with full type definitions
- Promise-based API

youtube-transcript test

Installation

``bash
npm install t-youtube-transcript-fetcher
`

Usage

`typescript
import { YoutubeTranscript } from 't-youtube-transcript-fetcher';
import { HttpsProxyAgent } from 'https-proxy-agent';

// Basic usage: Fetch transcript with default language
const transcript = await YoutubeTranscript.fetchTranscript(
'https://www.youtube.com/watch?v=dQw4w9WgXcQ'
);

// Fetch transcript in specific language
const spanishTranscript = await YoutubeTranscript.fetchTranscript(
'dQw4w9WgXcQ', // Can use video ID directly
{ lang: 'es' }
);

// Using pre-configured proxy agent
const proxyAgent = new HttpsProxyAgent('https://username:password@proxy.example.com:8080');
const transcriptWithProxy = await YoutubeTranscript.fetchTranscript('VIDEO_ID', {
proxyAgent: proxyAgent
});

// Alternative: Using proxy configuration object
const transcriptWithProxyConfig = await YoutubeTranscript.fetchTranscript('VIDEO_ID', {
proxy: {
host: 'http://proxy.example.com:8080',
auth: {
username: 'your-username',
password: 'your-password'
}
}
});
`

Example

Check out examples/fetch-transcript.ts for a complete example showing:
- Fetching transcripts with default language
- Fetching transcripts in specific languages
- Using proxy configuration
- Error handling

API

$3

Fetches the transcript for a YouTube video.

#### Parameters

- videoId: Video URL or ID
- config (optional): Configuration options
- lang: ISO language code (e.g., 'en', 'es', 'fr')
- proxyAgent: Pre-configured HttpsProxyAgent instance (takes precedence over proxy config)
- proxy: Proxy configuration object
- host: Proxy server URL (e.g., 'http://proxy.example.com:8080')
- auth: Optional proxy authentication
- username: Proxy username
- password: Proxy password

#### Returns

Promise resolving to an array of transcript segments:

`typescript
interface TranscriptSegment {
text: string; // The text content
duration: number; // Duration in seconds
offset: number; // Start time in seconds
lang: string; // Language code
}
`

#### Errors

The library throws specific errors for different cases:

- TranscriptError: Base error class
- RateLimitError: YouTube's rate limit exceeded
- VideoUnavailableError: Video doesn't exist or is private
- TranscriptDisabledError: Transcripts disabled for the video
- NoTranscriptError: No transcripts available
- LanguageNotFoundError: Requested language not available

Testing

This project uses Jest for testing. The test suite includes:

- Unit tests for core functionality
- Error message formatting tests
- Proxy configuration tests

To run tests:

`bash


Run tests

npm test

Run tests with coverage report

npm run test:coverage
`

Test reports and coverage information are generated in the coverage directory:
- Test Report: coverage/test-report.html
- Coverage Report: coverage/index.html

Project Structure

`
.
├── src/
│ ├── constants.ts # Constants and regex patterns
│ ├── errors.ts # Error classes
│ ├── types.ts # TypeScript interfaces
│ ├── transcript.ts # Main YoutubeTranscript class
│ └── index.ts # Public exports
└── examples/
└── fetch-transcript.ts # Usage examples
`

Error Handling

`typescript
try {
const transcript = await YoutubeTranscript.fetchTranscript(videoId);
// Process transcript
} catch (error) {
if (error instanceof RateLimitError) {
// Handle rate limiting
} else if (error instanceof VideoUnavailableError) {
// Handle unavailable video
} else if (error instanceof TranscriptDisabledError) {
// Handle disabled transcripts
} else {
// Handle other errors
}
}
`

Proxy Support

The library provides two ways to configure proxy support:

1. Using a pre-configured proxy agent (recommended for custom setups):
`typescript
import { HttpsProxyAgent } from 'https-proxy-agent';

const proxyAgent = new HttpsProxyAgent('https://username:password@proxy.example.com:8080');
const transcript = await YoutubeTranscript.fetchTranscript('VIDEO_ID', {
proxyAgent: proxyAgent
});
`

2. Using the proxy configuration object:
`typescript
const transcript = await YoutubeTranscript.fetchTranscript('VIDEO_ID', {
proxy: {
host: 'http://proxy.example.com:8080',
auth: { // Optional
username: 'your-username',
password: 'your-password'
}
}
});
`

The proxyAgent option takes precedence over the proxy` configuration if both are provided. Both methods will apply the proxy to all HTTP requests made by the library.

Credits

This project is an enhanced version of youtube-transcript by Kakulukian, with added features including:

- Proxy support with flexible configuration
- Enhanced TypeScript support
- Improved error handling
- More detailed documentation

License

MIT