  We study the problem faced by a service provider that has to sell services to
a user. In our model the service provider proposes various payment options (a
menu) to the user which may be based, for example, on the quality of the
service. Then, the user chooses one of these options and pays an amount to the
service provider, contingent on the observed final outcome. Users are not able
to observe directly the action performed by the service provide to reach the
final outcome. This might incentivize misconduct. Therefore, we propose a model
that enforces trust through economics incentives. The problem has two crucial
features: i) the service provider is responsible for both formulating the
contract and performing the action for which the user issues payments, and ii)
the user is unaware of the true action carried out by the service provider,
which is hidden. We study this delegation problem through the lens of contract
design, with the overarching goal of enabling the computation of contracts that
guarantee that the user can trust the service provider, even if their action is
hidden.
