Inclusion Criteria:  Have a smartphone Endorse a substance use concern Be between 18 and 65 years of age Be available and committed to engage with the Woebot app Be literate in English.(This is required for inclusion because all materials will be in English).  Exclusion Criteria:  Pregnancy (as W-SUDs will not be specifically developed to address the unique needs of this population) Suicide attempt within the past year (12 months) Symptoms of severe drug/alcohol history: History of delirium tremens; Experiencing hypertension, drenching sweats, seizures or confusion after stopping alcohol or drugs; Liver trouble (cirrhosis or hepatitis); Convulsions or GI bleeding due to drug/alcohol use Opioid overdose within the past year (12 months) Opioid misuse without medication-assisted treatment Not residing in the U.S. Ever used Woebot