Background <p>Home-based cardiac rehabilitation offers a cost-effective alternative model. However, long-term exercise adherence among patients remains suboptimal due to insufficient motivation. Self-Determination Theory and Nudge Theory provide the theoretical foundation for understanding behavioral drivers and designing low-burden intervention strategies. Therefore, this study aimed to develop a nurse-led, theory-driven, digitally platform-delivered nudge intervention program to improve long-term rehabilitation behavior in patients with chronic heart failure.</p> Methods <p>A multi-stage mixed-methods design was employed. In Stage I, based on prior evidence, a questionnaire survey was used to explore patient preferences regarding nudge strategies and delivery media; findings were finalized through expert panel discussion. In Stage II, an expert participatory theory co-design process was adopted. Experts from diverse professional fields were invited to develop the programme theory and elucidate hypothesized mechanisms. Expert response rate, authority coefficient, and Kendall concordance coefficient were used to systematically assess expert engagement quality, professional authority, and consensus level on the theoretical framework. In Stage III, the Nominal Group Technique was utilized to draft the digital nudge strategies. Subsequently, stakeholder meetings were conducted to refine and finalize the digital nudge strategy package.</p> Results <p>In Stage I, 486 patients with chronic heart failure participated in the survey. Patients most preferred the nudge strategies of pre-commitment (34.6%), alerts and reminders (21.8%), and social norms (18.1%), with the preferred delivery medium being an interactive online website (46.5%). In Stage II, the programme theory confirmed that pre-commitment, alerts/reminders, and social norms could activate core psychological needs (competence, autonomy, relatedness) respectively, thereby promoting sustained exercise behavior through motivational internalization. Kendall concordance coefficient for content importance and theoretical alignment were 0.765 and 0.868, respectively (<i>p</i> &lt; 0.05). In Stage III, the finalized digital nudge strategies, delivered via the interactive online system, included signing and publicly displaying commitment letters, contextualized alert notifications, and relatable peer modeling cases. This nurse-led digital nudge program is theoretically capable of improving exercise adherence in home-based cardiac rehabilitation for patients with chronic heart failure.</p> Conclusion <p>This study successfully developed a nurse-led digital nudge intervention. By utilizing pre-commitment, dynamic reminders, and social norms strategies to target the fulfillment of patients’ psychological needs, it provides a theory-driven, cost-effective, and patient-acceptable novel pathway to enhance adherence in home-based rehabilitation for patients with chronic heart failure. Subsequent research is needed to validate its long-term effectiveness and clinical translation value.</p> Clinical trial number <p>Not applicable.</p>