Build a RAG Application from Scratch — No LangChain, No LlamaIndex

In this tutorial, I’ll show you how to build a complete RAG application from scratch—no frameworks required. You’ll be able to chat with your own documents, whether they’re PDFs, Word files, or text files. We’ll use ChromaDB as our vector database and store all embeddings inside it. Google Colab Code: https://colab.research.google.com/drive/1uA29Pc33qEfT3bIZ6VuSYds2MMEwvbgH?usp=sharing *🧑🏻‍💻 My AI and Computer Vision Courses⭐* *📗YOLO26 Bootcamp: Real-Time Detection, Segmentation & Pose (13$)* https://www.udemy.com/course/yolo26-bootcamp-real-time-detection-segmentation-pose/?couponCode=PROMOTION10USD *📘Hands-On RAG Bootcamp: Build Apps with LangGraph & LangChain (13$)* https://www.udemy.com/course/hands-on-rag-bootcamp-build-apps-with-langgraph-langchain/?couponCode=PROMOTION13USD *📙Complete Computer Vision Bootcamp: YOLO to Multimodal AI (13$)* https://www.udemy.com/course/complete-computer-vision-bootcamp-yolo-to-multimodal-ai/?couponCode=PROMOTION13USD *📚 Generative AI, LLM Apps & AI Agents Masterclass 2025 (13$)* https://www.udemy.com/course/ai-agents-with-n8n-automate-anything-with-no-code/?couponCode=PROMOTION13USD *📘 YOLOv12 & YOLO26: Custom Object Detection & Web Apps 2026 (13$)* https://www.udemy.com/course/yolov12-custom-object-detection-tracking-webapps/?couponCode=PROMOTION13USD *📙 Modern Computer Vision with OpenCV 2025 (13$)* https://www.udemy.com/course/modern-computer-vision-with-opencv/?couponCode=PROMOTION13USD *📚 YOLO11 & YOLOv12: Object Detection & Web Apps in Python 2025 (13$)* https://www.udemy.com/course/yolo11-custom-object-detection-web-apps-in-python-2024/?couponCode=PROMOTION13USD *📘 AI 4 Everyone: Build Generative AI & Computer Vision Apps (13$)* https://www.udemy.com/course/ai-4-everyone-dive-into-modern-ai-with-llama-31-and-gemini/?couponCode=PROMOTION13USD *📙 YOLOv9, YOLOv10 & YOLO11: Learn Object Detection & Web Apps (13$)* https://www.udemy.com/course/yolov9-learn-object-detection-tracking-with-webapps/?couponC