Decentralized systems have always been a question and also a chance for humanity. As a decentralized system, blockchain had created an enormous interest in people at the present time. There are many reasons behind this interest, i.e. high price increase in crypto currencies. However from the point of computer science, blockchain is highly valuable software architecture. In our capstone project, we are developing a smart contract that holds currency data from TCMB(The Central Bank of Turkey) and ECB(European Central Bank) in Ethereum blockchain network.