Abstract This article examines migration dynamics in Mexico in the summer of 2023, after the end of title 42, which allowed U.S. border officials to directly deport migrants on the grounds of protecting public health during the Covid-19 pandemic. It discusses the question how the introduction of the U.S. Customs and Border Protection (CBP) smartphone app CBP One affects temporary migration dynamics. The data was collected through participant observation, digital ethnography, and interviews. The study period covers three months from June to August 2023. In Mexico, mainly in Tapachula and Tijuana, interviews were conducted with so-called extracontinental migrants who came from Uzbekistan, Afghanistan, and Ghana. Among other things, the interviews focused on their views of the CBP One app and how they felt on their journey through Mexico. This article concludes that CBP One is a new tool of the U.S. to control migration movements in Mexico, which fits into the picture of outsourced border controls and new technological measures that are also highly relevant in the European context. However, like other policies in the past, it is a fragile attempt to control migration movements. What is particular about it is the lottery character of asking for political asylum in the USA.