Marginalized communities are rarely included in the planning of research relevant to their own health or have access to research data. We implemented a community-based participatory research approach in developing a new health informatics system, WARP (Web Analytics Research Platform), to enable stakeholders to access and analyze research data. We leveraged data from a cohort study of 751 patients in the Transitions Clinic Network (TCN), a network of clinical programs serving patients with a history of incarceration. WARP holds de-identified, patient data, streamlines data processing (i.e. transformation, archival, and partitioning), and has a web analytic tool for users to perform statistical analyses. We used feedback from focus groups of patients with a history of incarceration and workshops with TCN research teams, including patients, community health workers and policymakers, to develop WARP. Our approach advances mechanisms to engage stakeholders in research. Future work will evaluate its effect on community-engagement in research.