This thesis deals with the implementation of a system for acquiring and processing transactions from various cryptocurrency blockchains. The aim of the thesis is to design and implement a system as a library that provides a unified interface for working with multiple blockchain networks. A key feature of the proposed system is its modularity, which enables future expansion to support additional cryptocurrencies. The thesis describes the architecture of selected blockchains and analyzes existing methods of obtaining data from these networks. Based on an analysis of available tools, Tatum.io was chosen as a suitable platform, as it offers interfaces for communication with a large number of blockchains. Subsequently, a general library model with an adapter-type architecture was designed, where each adapter ensures communication with a specific blockchain. The implementation was carried out in the Typescript language. The resulting library allows the user to track transactions based on specified parameters, which are: tracked address, time range (or block range), and blockchain type. The contribution of this work is the creation of a universal interface between the user and various blockchains without the need for detailed knowledge of them.