Decentralized smart contract software service using ETHEREUM blockchain non-fungible tokens

The decentralized technologies of the Ethereum blockchain were analyzed, based on the principles of which a decentralized software service solution was proposed using a smart contract implemented in the specialized Solidity programming language. This contract acts as one of the elements of the server-client application and is the server part for processing methods of interaction with the Ethereum blockchain. The methods include a set of various functions, including for interacting with a collection of non-fungible tokens. The metadata that describes the digital product (non-fungible tokens) is directly linked to the blockchain and resides in a decentralized repository for its most reliable and long-lasting existence. The Ethereum blockchain, in addition to development tools, provides stable support for developers and users thanks to the popular decentralization paradigm, and the relevance and constant development of technologies lead to user interest in products created on their basis. Non- fungible tokens can be used as a cryptocurrency unit, and the decentralized application itself as a platform for collecting funds for a specific purpose. The methods of creating decentralized software services using smart contracts of non-fungible tokens were studied. The selection of the main nodes of the decentralized application is substantiated. A detailed functional diagram of the operation of the basic smart contract methods is proposed together with a diagram that describes all the functional nodes of the decentralized application in general. The results of the interaction of the client part of the software service with the smart contract of the Ethereum blockchain are also demonstrated.