📺 AskYouTube: AI Context Assistant (RAGTube)

An interactive Retrieval-Augmented Generation (RAG) web application that transforms any YouTube video into a live chat stream. Built with FastAPI, LangChain, FAISS, and Google Gemini, this tool indexes video transcripts in seconds and delivers precise, context-aware answers inside an authentic YouTube Dark Mode interface.

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✨ Key Features

• ⚡ Instant Video Indexing: Paste any YouTube URL or video ID to dynamically fetch and chunk text transcripts using youtube-transcript-api.
• 🧠 Advanced RAG Pipeline: Uses HuggingFace local embeddings (all-MiniLM-L6-v2) and an in-memory FAISS vector database for blazing-fast semantic search.
• 🤖 Powered by Google Gemini: Integrates Google's gemini-2.5-flash-lite model for high-speed reasoning and accurate conversational summaries without hitting strict free-tier quota limits.
• 🎨 Authentic YouTube Dark UI: Designed from the ground up to mirror YouTube Live Chat, featuring pill buttons, neon live-status indicators, custom CSS username badges, and smooth scrollbar auto-locking.
• 📑 Source Inspection: An interactive accordion lets developers and users inspect the exact transcript chunks retrieved from the vector database for every answer.
• 🛡️ Zero-Censorship & Fallback Safeguards: Configured with custom safety settings and whitespace validators to prevent blank or silently blocked chat responses.

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🛠️ Tech Stack

• Frontend: HTML5, Custom CSS3 (YouTube Dark Theme), Vanilla JavaScript (Fetch API)
• Backend: Python 3.10+, FastAPI, Uvicorn, Pydantic
• AI & Orchestration: LangChain, Google Generative AI (gemini-2.5-flash-lite), HuggingFace Sentence Transformers
• Vector Database: FAISS (Facebook AI Similarity Search - CPU)

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📂 Project Structure

├── frontend/
│   ├── index.html       # YouTube Live Chat UI blueprint
│   ├── style.css        # Dark mode styling, glowing badges & flexbox fixes
│   └── script.js        # Frontend API client & markdown text formatter
├── app.py               # FastAPI server & LangChain RAG pipeline
├── requirements.txt     # Locked Python package dependencies
├── .env                 # Hidden API keys (Not tracked in Git)
├── .gitignore           # Security and cache exclusion rules
└── .gitattributes       # Forces GitHub to classify repo as 100% Python

💻 Running the Application

• Start the FastAPI backend server with auto-reload enabled:

• uvicorn app:app --port 8000 --reload

• Open your web browser and navigate to:

• http://localhost:8000 (Or double-click frontend/index.html to run the UI directly)

• Paste a YouTube URL (e.g., https://www.youtube.com/watch?v=Gfr50f6ZBvo), click Connect Transcript, and start chatting with the AI!