Master Store is one of the main systems that governs store data contained in PT XYZ, the master store system is still running and works with Monolithic architecture which requires that every new and old application PT XYZ must duplicate the master store database, this can cause weakening and database performance decreases over time. Making Master Store Application Programming Interface aims to change the architecture currently used into Microservices where the Master Store system can then be used continuously by other applications and make it easier for developers to build new applications using the master store database without fear of a decline in the master store database.. The design of this API uses the Python programming language because it is a safe and simple programming language, Flask framework, REST communication standards, and ORM methods. ORM method was chosen because the security system is better compared to native queries in general, especially because of the process and development of ORM methods based on previous research. The results this study are the dynamic Master Store API that provides store data response, based on what PT XYZ developers need for applications and programs that are built.