Blockchain technology has become increasingly popular in recent years. However, only 8% of blockchain open source projects are maintained actively on GitHub. Drawing on the online leadership literature, this study seeks to understand the correlation between leader characteristics and success of blockchain open source projects from the behavioral (knowledge contribution), structural (social capital) and cognitive (openness orientation) dimensions. Considering the unique decentralization nature of blockchain, this study further investigates the contingency effect of blockchain archetypes with empirical evidence from GitHub. Our findings provide novel insights for understanding the determinants of blockchain open source project success and leadership behaviors in the online community.