This paper examines how firms can govern hybrid-knowledge management to transform sustainability information into customer-perceived competitive value. The study starts from a practical problem related to sustainability investments, which often fail to generate advantage. This occurs because customers receive fragmented or poorly translated signals. In response, the paper defines hybrid-knowledge management as the deliberate design and governance of customer-facing hybrid sustainability knowledge flows. These exchanges combine AI-generated cues with human-mediated interpretation provided by influencers, frontline employees, and brand communicators. The research asks how sustainable competitiveness can be strengthened through hybrid-knowledge mechanisms involving both humans and AI agents. A qualitative multi-case study design is adopted, involving four cases selected across the food and fashion industries. This setting was chosen because both sectors are highly exposed to sustainability-sensitive consumer choice and feature visible customer journeys in which knowledge is mediated through both digital and human channels. Data collection combined direct observation of customer-facing interfaces and campaign touchpoints with documentary secondary sources, enabling triangulation across firms, channels, and touchpoints. Data were analysed inductively through the Gioia methodology. The findings show that sustainable competitiveness is shaped by three interrelated levers. First, claim integrity, which rests on sustainability cues being auditable, standardised, and accompanied by human explanation. Second, choice guidance, which requires sustainability information to be translated into decision-ready comparisons at the point of choice. Third, relational sensemaking, which depends on customers’ ability to resolve ambiguity through trusted human interaction and receive continuity after purchase. Across the cases, no instance of full alignment was observed. Two-lever configurations generated partial clarity, while one-lever configurations produced sustainability blur, scepticism, or weak conversion. The paper contributes by theorising hybrid-knowledge management as a strategic capability for orchestrating customer perceptions of sustainability, rather than as a purely internal knowledge process. It also offers actionable implications for managers, specifically to align verification, explainability, and human interpretation across touchpoints, and for policymakers seeking stronger traceability and comparability standards in both digital and human communication channels.