Build Your Own Language Model: From Raw Text and Tokenizers to a Safe, Tool-Using Multimodal AI Assistant (Made Simple AI Series Book 3)

Build Your Own Language Model is a practical guide to understanding and creating modern language-model systems from the ground up. Beginning with raw text, legal data collection, and multilingual byte-level tokenization, the book walks readers through transformer architecture, causal attention, GPT-style model training, instruction tuning, LoRA, preference optimization, evaluation, inference, retrieval-augmented generation, tool use, agents, memory, safety, and multimodal AI. Readers will learn how to: • Build clean, traceable training datasets • Train and evaluate a multilingual tokenizer • Implement transformer and GPT-style model components • Fine-tune models with instruction and preference data • Build citation-first retrieval systems • Design bounded AI agents with safe tool access • Combine text, image, and audio capabilities • Plan original AI research and run reproducible experiments • Complete seven practical projects with measurable evidence The book combines clear explanations, compact code examples, diagrams, troubleshooting guidance, research methods, and companion code. It is designed for learners, developers, teachers, and researchers who want to move beyond using AI systems and begin building capable systems of their own.