Abstract：Developing an open source mobile app in library servicesthe case of a national university in Malaysia Purpose A surge of library activities and technological advances have increased the demand for data accuracy and agility among library clienteleThereforenovel approaches are needed to extend library servicesThis paper aims to introduce the implementation of a prototype mobile library applicationappdesigned using an in-house open source systemKohaDesignmethodologyapproach This paper presents a case study using a metamorphosis process to create mobile appsThis case study is tested based on the library services with a set of activities during the system acceptance testSATand also user acceptance testUATAn application programming interfaceAPIused to support two-way communicationincluding system-to-component and system-to-system connectivityThe designfeatures and advantages of this mobile app are discussedillustrated and analyzedThe case study reports the mobile app version development from the Koha Open Source Library Information SystemFindings The app was tested using user acceptance testUATand system acceptance testSATby library staffs who found it functionalaccessibleappealing and usefulFeatures such as Online Public Access Catalog searchlibrary collection scanningpatron accountspatron personal book collectioncirculationlibrarian chatQR codes for borrowing bookssocial media integration and notifications of library activities and events were successfully testedThis process was useful for the creation of a mobile app based on the existing library System-Koha Open Source SystemResearch limitationsimplications This study is limited to a case study of a national university in MalaysiaPractical implications This study has some practical implications for implementing library mobile applicationsegit will encourage librarians to implement library applications in librariesOriginalityvalue This study is useful for mobile developers and libraries that plan to offer mobile library services to their patronsThis paper presents a case study of metamorphosis existing process of library open source System-Koha Open Source SystemLibrary AutomationLibrary AutomationandRetrieval and IndexingThe described mobile apps have a variety of functionssuch as online public accesscollectionreaderspersonal account collectioncirculationbook collectionbook collectionbook collectionbook collectionbook collectionbook collectionbook collectionlibrary Librants chatetcThis article mainly introduces how to use the open source system KOHA to design and implement a library mobile phone application