YouTube Transcript Summarizer

An application for extracting YouTube video transcripts and generating concise AI-powered summaries.

🚀 Features

• YouTube transcript extraction via YoutubeExplode
• AI summarization: concise summary (3-10 points) using LLM (OpenAI or local LLM)
• Automatic fallback: if OpenAI is unavailable, local LLM (Ollama) is used
• Modern UI: responsive Angular 19 frontend with latest features
• REST API: .NET 9, production-ready
• Health-check endpoint: /api/health
• Unit/integration tests for backend and frontend

🛠️ Tech Stack

• Backend: .NET 9, YoutubeExplode 6.5+, OpenAI API, Ollama (local LLM)
• Frontend: Angular 19, RxJS 8, TypeScript 5.6+, modern standalone components
• Testing: xUnit, Angular TestBed

📋 Requirements

• .NET 9 SDK
• Node.js 18+ and npm
• Angular CLI 19+
• OpenAI API key (optional)
• Ollama (optional, for local LLM)

🏁 Quick Start

1. Clone the repository

git clone <repository-url>
cd YouTubeTranscriptSummarizer

2. Backend setup

cd src/YouTubeTranscriptSummarizer.API
dotnet restore
dotnet run

3. Frontend setup

cd client
npm install
ng serve

4. Health Check

curl http://localhost:7001/api/health
# Response: { "status": "Healthy" }

⚙️ Configuration

Edit src/YouTubeTranscriptSummarizer.API/appsettings.json:

OpenAI (recommended)

{
  "OpenAI": {
    "ApiKey": "your-openai-api-key-here",
    "Model": "gpt-3.5-turbo"
  }
}

Local LLM (Ollama)

1. Install Ollama: https://ollama.ai/
2. Download a model:

ollama pull llama2

3. Configure:

{
  "LocalLLM": {
    "Model": "llama2"
  }
}

If OpenAI is unavailable, local LLM (Ollama) will be used automatically.

🧪 Testing

• Run backend tests: dotnet test src/YouTubeTranscriptSummarizer.API.Tests
• Run frontend tests: ng test (from client directory)

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