We examine whether psychological contract theory can explain users’ responses to e-commerce recommendation agents (RAs). Theories of social response to technology, trust in technology, and technology adoption are used to adapt psychological contract theory from the interpersonal domain to user-RA domain. We theorize that a psychological contract breach will cause a negative emotional reaction, called a psychological contract violation, which, via trust and usefulness perceptions, will influence users’ intentions to follow an RAs’ recommendation. Two studies elicited perceived user-RA mutual obligations, which form the basis for the posited psychological contract. We outline a Study 3 to measure preference strength for these obligations, and a Study 4 to test the effect of breaching these obligations on theorized emotional, cognitive, and behavioral reactions to the RA. Using these studies, insights can be gained about how to design RAs to achieve important business results and avoid negative side effects.