There are indeed "coalgebraic" descriptions of OOP. - "Objects and Classes, Coalgebraically" (1995) http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.29

There are indeed "coalgebraic" descriptions of OOP. - "Objects and Classes, Coalgebraically" (1995) http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.29.6018 http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.29.6... - "Codata in action" (2019) https://www.microsoft.com/en-us/research/publication/codata-in-action/ https://www.microsoft.com/en-us/research/publication/codata-... Coalgebras fit very well with the "hidden internal state" that characterizes objects in OOP.