Automated legal analysis of rental contract clauses using large language models

This work presents a software tool for the automated legal analysis of rental contract clauses using large language models (LLMs). The system extracts clause-level segments from .docx files and generates legal evaluations and rewritten alternatives using multiple LLMs (GPT-4, GPT-4o, GPT-3.5, DeepSeek). Each clause is assessed for legality, abusiveness, vagueness, risk, and legal gaps according to Spanish housing law. A unified JSON structure stores the outputs for reproducibility and benchmarking. The tool enables comparative analysis across models and provides a foundation for future research on AI-assisted legal drafting and clause evaluation.