Biodesign projects often stall between promising material prototypes—bacterial cellulose textiles, mycelium composites, algae-derived materials—and scalable, economically viable production systems. This gap emerges from fragmented decision-making across material design, cultivation processes, and techno-economic evaluation, since each domain operates with distinct metrics, vocabularies, and decision thresholds—making cross-domain reasoning difficult to formalize and transfer. We present agents.design.bio, a decision-support framework that enables students, designers, educators, and founders to engage interdisciplinary expertise through structured reasoning. The platform offers a unified conversational interface in which users interact with domainspecific agents: Designer (@designer), Farmer (@farmer), and CFO (@cfo). Together, they operate on a shared knowledge base, manufacturing datasets, and techno-economic models. Rather than generating speculative ideas, the agents evaluate user-defined scenarios and highlight trade-offs, sensitivities, and risks—making cross-domain dependencies explicit and testable. The demonstration walks through four phases— material evaluation, process optimization, scale-up stress testing, and trade-off analysis—reframing scale-up as a structured learning process rather than a late-stage financial constraint.