Background: Chemotherapy treatments are increasingly provided in the outpatient setting. Patients are expected to monitor and manage a range of diverse and complicated side-effects without readily accessible clinical support. The overall goal of this study is to address the gap in continuity of care during outpatient chemotherapy through the integration of an innovative text messaging system with a Chatbot interface in the real-time monitoring and proactive management of side-effects among gastrointestinal (GI) cancer patients undergoing IV chemotherapy. Methods: Real-time chemotherapy-associated side effects monitoring supportive system (RT-CAMSS) was iteratively developed with patient-centered inputs and evidence-based and theory-guided information to address chemotherapy knowledge, self-care symptom management skills, emotional support, doctor-patient communication, and nutritional and physical activity suggestions. We conducted a single-arm 2-month pilot study, in which GI patients undergoing chemotherapy received two intervention text messages per week and a weekly CTCAE-based symptom assessment delivered through Chatbot interface with tailored feedback. Baseline and post-intervention patient-reported outcome follow-up surveys were collected. Results: 45 eligible patients were approached and 34 consented and enrolled (76% consenting rate). The mean age was 61 (±12). 56% were females and 61.8% were non-Hispanic White. The most frequent cancer type was pancreatic cancer (53%), followed by colon cancer (35%). 27 participants completed the post-intervention follow up (79% retention rate)..Functional wellbeing subscale of the FACT instrument showed significant improvement from baseline to 2 month (p< 0.05). 27 participants responded to the weekly Chatbot-interfaced symptom assessment at least once (79% feasibility rate). The most frequent reported symptom collected from Chatbot assessment was constipation (50%), followed by weight loss (35%) and fatigue (32%). Post-intervention open-ended satisfaction survey found that participants perceived the intervention easy to use with helpful information. Conclusions: Communication via mobile technologies is highly scalable for improving health services. The study provides preliminary evidence of engagement, acceptability and benefits of RT-CAMSS, which should be evaluated in a controlled clinical trial.