Summary The objective of this supplement proposal is to collect standardize provenance metadata of the Neuroscience Gateway (NSG) datasets and computational tools using a provenance ontology, which will enable them to be AI/ML ready. The NSG project began in 2012 to catalyze progress in neuroscience by reducing technical and administrative barriers that neuroscientists faced in large scale modeling projects which require high performance computing resources. NSG's success is reflected in the facts that its base of registered users (currently 1370) has grown continually since it started operation, every year the NSG team successfully acquires over 14,000,000 core hours of time on NSF funded supercomputers and it has contributed to large number of publications and Ph.D./MS thesis. Starting in 2017 experimentalists and cognitive neuroscientists began to use NSG for data processing/analysis and ML. NSG now provides over sixteen tools on supercomputers for simulation, data processing and ML. As promised in the parent U24 grant awarded in 2019, we have enhanced NSG by adding new features making it an efficient environment for development and dissemination of lab-developed neuroscience tools to the broader neuroscience community. It should be noted that currently there is no provision to record metadata or provenance information for any of the NSG tools and the data sets they produce. Currently the large number of NSG computational tools and the datasets lack standardized annotations that is needed to enable them to be integrated into ML workflows with support for explainable AI and reproducibility. In this supplement, we will first integrate a W3C PROV specification-based provenance ontology in NSG through a provenance interface to allow users to record provenance metadata using ontology classes. We will demonstrate the use of provenance ontology through a pilot project that will use a neuroscience software called the NeuroIntegrative Connectivity (NIC) tool that analyzes EEG data to compute functional brain networks in neurological disorders. The NIC tool has provenance metadata characteristics built into it, and will be the first NSG tool to carry the metadata provenance information from the beginning to the end of a dataset’s lifecycle. The ontology-based standardized description of both the NIC tool and data will enable NSG to make them findable, accessible, interoperable, and reusable. In this context, providing a secure method to efficiently share and verify the data and metadata is necessary for reuse of scientific data. To achieve this, we will utilize the NSF-funded Open Science Chain (OSC) project which provides a blockchain based solution to maintain the integrity and provenance for datasets and its metadata and provides a way to perform independent verification of the data stored in the blockchain. The experience gained via integrating a provenance ontology, the NIC tool and the OSC within the framework of NSG, will allow us in the future t...