The initial plan was not to build a chatbot.

Rather, programmer Eugenia Kuyda composed Replika while working at Luka, a tech company she cofounded in 2012. The ambition was to come up with a platform that could offer restaurant recommendations to those visiting new cities, sorting out preferences and aggregating suggestions from locals.

In her personal life, however, Kuyda was faced with less quotidian matters: a close friend of hers had just died in a traffic accident. Dumbstruck by their passing, Kuyda began to experiment with scripts from her app in development, feeding it messages from old logs to evoke an artificial presence. “I found myself looking at these old text messages,” she recalls, “and it struck me all of a sudden . . . .  What if I could build a chatbot so I could actually text him and get some-thing back?”