Ex Machina

Caleb, a coder at the world's largest internet company, wins a competition to spend a week at a private mountain retreat belonging to Nathan, the reclusive CEO of the company. But when Caleb arrives at the remote location he finds that he will have to participate in a strange and fascinating experiment in which he must interact with the world's first true artificial intelligence, housed in the body of a beautiful robot girl.

This is a current release, so it is not free to download. The legal options are renting, buying or streaming it on a service you already pay for. Every link goes to the store that holds the rights.