Object traceability based on Radio Frequency IDentification (RFID), an important capability of the Internet of Things (IoT), has improved our quality of life (e.g. anti-counterfeit). GS1 EPCglobal, a de facto standard in RFID technology, develops EPC Information Service
(EPCIS) in order to capture and share standardized events representing various aspects on tag-attached object. However, the current standard is detrimental to the connection of the facts on RFID events, thus yielding query inefficiency, especially for object trace. Also, even the problem becomes worse when the event repositories are distributed. In this paper, we propose the graph-based platform for enhanced object traceability over unified and linked EPCIS events, EPC Graph Information Service. The main contributions of the paper are as follows. Firstly, we propose the graph model on standard EPCIS document called EPC Graph Model, which would be an efficient approach for connecting RFID events in a unified manner. Secondly, we propose the library for the distributed services called EPC Graph Crawler based on fundamental REST APIs for utilizing EPC Graph. By using the library, application developers are able to utilize distributed EPC Graphs as if all the graphs are managed in a centralized platform.