Stress is a major health issue in contemporary society, and mindfulness-based approaches reduce stress and anxiety but face practical barriers to consistent practice; this protocol evaluates a Virtual Reality (VR)-based observation meditation programme with an artificial intelligence (AI) coach (‘Otti’) that delivers real-time empathic, tailored prompts to support present-focused attention and emotion regulation in university students in the United States. A single-centre randomised controlled trial in Pennsylvania will assess immediate psychophysiological effects and user acceptability after a single 15 min session following a standardised Stroop stressor in a university laboratory setting.

An a priori power analysis (f=0.25, α=0.05, power=0.80) supports recruitment of 34 students (n=17 per group) in a single-centre randomised controlled design comparing AI-coached VR observation meditation to a no-treatment leisure control within a 30 min visit. Participants complete pre-intervention surveys Perceived Stress Scale-10 (PSS-10), Depression Anxiety Stress Scales (DASS-21), State–Trait Anxiety Inventory (STAI-State, STAI-Trait) and baseline heart rate/Heart Rate Variability (HRV) via smartwatch, undergo the 15 min intervention or control, then complete postintervention surveys and repeated heart rate/HRV recording; effects will be tested using repeated-measures analysis of variance, with heart-rate data exported and preprocessed per the prespecified plan. Primary outcomes include perceived stress (PSS-10), emotional state (DASS-21, STAI-State, STAI-Trait), physiological stress response (heart rate/HRV) and participant satisfaction via a structured postintervention survey (usability, perceived effectiveness, comfort).

The study received IRB approval from The Pennsylvania State University Institutional Review Board (PSU CATS IRB: STUDY00025978; ClinicalTrials.gov: NCT06704282), and all participants will provide written informed consent prior to procedures. Findings will be disseminated via open access publication, conference presentations and stakeholder-focused briefs, with an anonymised primary-outcome dataset available on reasonable request in line with BMJ Open policies and Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT)/International Committee of Medical Journal Editors (ICMJE) guidance.

NCT06704282.