Check out the documentation in the Getting started page
The sandbox is an environment in which you can test the integration between your application and Mediobanca Premier APIs.
In the sandbox, you will get test data from the APIs; in the production environment you will get live data and execute the operations for real.
You can request access to the sandbox anytime; to request access to the production environment you have to register as an AISP/PISP with your EBA-id and your EIDAS certificates (see also PSD2).
You can find a detailed description of the signature method here
You can find the possible HTTP status codes we use with their meaning here
You can go here
If you didn't receive your verification email, you can contact us here
The PSD2 directive force a bank service provider like us to expose our APIs to external service provider authorized by the European Banking Authority (EBA)
To verify that you are who you are telling us and that you are authorized by EBA, we need you to give us your EBA registry identifier and your client certificates (which guarantee your identity).
To request credentials to access Mediobanca Premier APIs, you have to be registered. Then, you will find the application request page under the Profile section.
If you're registered as a simple user, you'll be able to request credentials for the sandbox environment only; if you need access to production, you'll have to declare yourself as an EBA registered entity (you can do it in the Enrollment page under the Profile section).
You can contact us here