With the expansion of cyberspace and the integration of artificial intelligence into decision-making processes and document drafting, electronic contracts have transformed from a technological phenomenon into a central topic in contemporary Iranian law. The fundamental question is: in situations where the process of concluding or executing contracts is carried out through artificial intelligence, how is the legal validity of these contracts proven, and to what extent can digital messages and digital signatures be relied upon as trustworthy evidence? The aim of this research is to analyze the mechanisms for validating electronic contracts within the Iranian legal system by examining the differences and functions of three evidential elements: presumption, legal fiction, and legal rule, within the context of new technologies. In this pursuit, the question the research seeks to answer is: “Which of these elements plays a more effective role in proving the authenticity, intent, consent, and validity of a contract in the electronic space with the intervention of artificial intelligence?” The research methodology is based on a descriptive-analytical study and a comparative review of Iran’s E-commerce Law, Civil Procedure Code, and judicial practice. Findings indicate that digital presumptions based on behavior, timestamps, and metadata play a significant role in proving contractual relationships; existing legal fictions are mainly limited to attributing digital messages; and general legal rules have relative applicability to smart contracts, but still require legislative completion. In conclusion, the Iranian legal system must, by amending evidential rules, provide a secure and reliable framework for the acceptance of AI-based contracts.