In its internal model, a smart contract is a code or a program that executes commands automatically and without the need for intermediaries when certain conditions are met, and for this reason, it is not considered a contract in the internal model. But the smart contract in its external model are agreements that are included as an implicit condition in the main contract. Therefore, they are considered as contracts in the foreign model.

Providing for the rapid development of technology and the daily and comprehensive use of smart contracts. The need to discuss this issue is clear. In this research, using the library data collection method and the descriptive and analytical data processing method, the juristic-legal foundations of smart contracts have been investigated. It seems that the legitimacy of smart contracts under indefinite contracts can be proven according to the general evidence regarding transactions and jurisprudence rules such as the principle of authenticity. Also, with a comprehensive view of the principle of freedom of contracts as an accepted principle in the subject laws of Iran, the aforementioned contracts can be considered as examples of Article 10 of the Civil Code of the Islamic Republic of Iran.