This toolkit describes the Startup Enabler Capability Assessment (SECA), a tool designed specifically to measure the capabilities of startup enablers. It is applicable to a variety of types of startup enablers. It measures 44 dimensions grouped under seven organizational capabilities-financial capital, strategy, human capital, networks, advocacy and political capital, leadership and governance, and management and organizational processes. The tool comprises four phases: a classification and mapping phase, a stakeholder consultation and issue discovery phase, a broad data-gathering phase, and a deep-dive structured interview phase. It is intended to allow comparisons over time and geography and has been piloted in Romania through a separate initiative in collaboration with the Ministry of Research, Innovation and Digitalization. This toolkit uses the results from the pilot to illustrate the methodology.