Many pesantren in Indonesia hold rich relational resources yet still struggle to turn them into a stable financing system. This study examines how an Islamic boarding school converts social capital into financial and nonfinancial resources, and how that conversion can be organized into a coherent financing model. The research used a qualitative ethnographic design carried out over three months in 2025. Informants were chosen purposively and expanded through snowball sampling until the data reached saturation, and they included the pesantren leader, the treasurer, business-unit managers, guardians, and alumni. Data came from participant observation, in-depth interviews, and documentation, then went through condensation, display, and conclusion drawing, with triangulation, member checking, and an audit trail securing trustworthiness. The findings show that financing rests on a mixed pattern in which trust, networks, and participation become student payments, infak, waqf land, volunteer labor, and business-unit revenue through bonding, bridging, and linking social capital. A digital finance system manages these resources and diversifies them across several productive units, forming a cycle that moves from social capital to resource mobilization, governance, diversification, asset formation, self-reliance, and renewed trust. The study contributes a model that treats social capital as a strategic and institutionalizable financial asset rather than the by-product of a leader's charisma. Its main implication is that pesantren can strengthen financial independence and educational continuity by deliberately building trust, widening networks, and sustaining community participation among guardians, alumni, and partners.