This article analyses the role of certain Web writing tools, APIs or “programming interfaces”, in the production of texts on the Internet. Positing these tools as places of a “literary practice” where an editorial function is carried out, the author shows that certain conceptions of text unfold in computer code. Drawing on the example of the APIs of Facebook and Twitter, he shows that the discretization inherent to computing plays a decisive role in the exercise of this editorial function, and that this discretization currently serves the intensified circulation of texts on the Internet. The APIs and the computer code that they make possible to write are thus identified as one of the essential elements of a contemporary text industry.