Psychosocial treatments for methamphetamine dependence are of limited effectiveness. Thus, a significant need exists for add-on therapy for this substance user disorder. The aim of this study was to develop and test a novel text messaging intervention for use as an adjunct to cognitive behavioral group therapy for methamphetamine users. Text messaging has the potential to support patients in real-time, around the clock. We convened two meetings of an expert panel, held three focus groups in current and former users, and conducted 15 semi-structured interviews with in-treatment users in order to develop a fully automated, cognitive behavioral therapy-based text messaging intervention. We then conducted a randomized, crossover pre-test in five users seeking treatment. Participants' ratings of ease of use and functionality of the system were high. During the pre-test, we performed real-time assessments via text messaging on daily methamphetamine use, craving levels, and the perceived usefulness of messages; 79% of scheduled assessments were collected. The odds of messages being rated as "very" or "extremely" useful were 6.6 times (95% CI: 2.2, 19.4) higher in the active vs. placebo periods. The intervention is now ready for testing in randomized clinical trials.