Digital modeling of the real world with 3D modeling technologies has recently prepared the groundwork for Metaverse. Metaverse is an ecosystem that will allow social and cultural events in the real world to be carried out in the digital world as well. Inspired by this framework, this study presents an approach called MetaRepo, where users can securely store digital assets (cryptocurrency, avatars, clothes, tickets, etc.) and use them in various activities within the metaverse universe. The motivation for the realization of this study is the security problems in the exchange, buying and selling transactions that take place in the virtual universes that have become popular in recent days. Another source of motivation is the anxiety of the object owners having their possessions stolen, lost, and transferred to another universe in the Metaverse. Blockchain technology, which can store assets in MetaRepo, has been used to address these concerns. In the developed blockchain structure, New User Engine, Transaction Centre, Authenticator Engine (W-eng) and Repos models have been developed for user interaction, transaction processing and security mechanism. An exemplary metaverse universe including social activities has been designed for the testing and evaluation processes of the proposed MetaRepo approach. MetaRepo is communicated from the browser via APIs. Detailed performance analysis has been carried out for the proposed model. As a result, with MetaRepo, a mechanism is aimed at which users can communicate with different metaverse universes and platforms without the need for extra verification and security measures within the metaverse universe.