Objective: This study captured the interrelationships among craving, negative affect, and positive and negative social exchanges in the daily lives of patients in residential treatment for opioid use disorders (OUDs). Method: Participants were 73 patients (77% male), age 19 to 61 (Mage = 30.10, SDage = 10.13) in residential treatment for OUD. Participants completed a smartphone-based survey 4 times per day for 12 consecutive days that measured positive and negative social exchanges (Test of Negative Social Exchange), negative affect (PA-NA scales), and craving (frequency and intensity). Within-person, day-level associations among daily positive and negative social exchanges, negative affect, and craving were examined using multilevel modeling. Results: Daily negative social exchanges (M = 1.44, SD = 2.27) were much less frequent than positive social exchanges (M = 6.59, SD = 4.00) during residential treatment. Whereas negative social exchanges had a direct association with same-day craving (β = 0.08; 95% CI = 0.01, 0.16, ΔR2 = 0.01), positive social exchanges related to craving indirectly via moderation of the within-person negative affect-craving link (β = −0.01; 95% CI = −0.01, −0.001, ΔR2 = 0.002). Positive social exchanges decoupled the same-day linkage between negative affect and craving on days when individuals had at least four more positive social exchanges than usual. Conclusions: These results indicate that both negative affect and negative social exchanges are uniquely related to craving on a daily basis, and that extra positive social interactions can reduce the intraindividual coupling of negative affect and craving during residential treatment for OUD.