Many traditional business-to-business (B2B) firms across industries have introduced digital platforms to enhance joint value creation and productivity, using artificial intelligence (AI) for platform development. Platform owners play a critical role in such platforms’ governance and in designing platform-based business models (BMs) to foster value creation within platform ecosystems. Given the complex architecture of B2B platforms, platform owners must continuously renew their capabilities and shift their mindset throughout the platform lifecycle to innovate new platform-based BMs, and they increasingly use AI tools for this purpose. However, little research on business model innovation (BMI) has focused on how managers can shift their mindsets to support the evolution of digital platforms or how AI can support these shifts. Therefore, this study investigates how AI is advancing BMI in the platform context and what mindset shifts must occur in managers. We focused on nine traditional firms that are B2B platform owners and interviewed 15 managers. Our findings show that AI plays three distinct roles in the evolution of a digital platform’s BMI: AI as Optimizer, as Expander, and as Creator. Our findings emphasize that AI-powered BMI in platform ecosystems is not solely technology driven but also requires significant shifts in managers’ mindsets. We also provide practical insights, demonstrating how AI’s capacity to process vast amounts of data can empower platform owners to develop more sophisticated BMI. Furthermore, we encourage managers in traditional firms to reflect on their own mindsets during digital platform evolution. • This study shows how firms use AI to develop platform-based BMs. • Mindset shifts are vital for BMI in B2B platform firms. • AI supports platform-based BMI through three distinct AI-powered roles. • AI enables platform owners to optimize, expand, and create new BMs. • BMI is driven by both AI adoption and shifts in managerial mindsets.