The study explores ways on how best to systematize and institutionalize collaboration in peace and security between the African Union (AU) and the Regional Economic Communities (RECs), with civil society organisations (CSOs) in Eastern Africa. The focus lies on areas of conflict prevention, early warning, and early response. Gaps in the collaboration of AU/RECs in engagement with CSOs are identified and duplication of efforts are highlighted. The study suggests ways of creating synergies between the AU, RECs and CSOs in in conflict prevention and early warning, especially by learning from the experiences of the West Africa Network for Peacebuilding (WANEP).