Yes there is no official API , basically the tool scrap HTML website content, I don't know if that is legal or illegal according to EU laws.
but its like scrapping Google search result, and I remember that it was illegal in the US law.
I think leboncoin.fr has the right to ask him to stop the service. but they also have to offer an API to the developers who seek to tweak the service .
I think leboncoin.fr has the right to ask him to stop the service. but they also have to offer an API to the developers who seek to tweak the service .