Change connection used on runtime

I hope you can help me (us). I'm working on a API project which have two databases :

Production DB : api.myapp.fr

Testing DB : test.api.myapp.fr

Theses two databases are writable by the user.

When a user call our API, he can set the authorization header whichever he needs. For example :

Authorization: s_0

Will perform operations on api.myapp.fr and

Authorization: s_t_0

Will perform operations on test.api.myapp.fr .

My question is : How can I do that with sails ?

Actually, I have a policie which check if the user is using a production key or a testing key, and I override the default models with the one for testings purposes, like this :

if (!is_production) {
    req.session.isProd = false;
    req.session.logs.environment = "test";

    User = UserTest;
    Payment = PaymentTest;
    PayzenStatus = PayzenStatusTest;
    Transaction = TransactionTest;
    Card = CardTest;
    Doc = DocTest;
}

But you can see the problem if a user makes a test request and then a production request, the models are still the tests ones...

I use my models in services and policies, therefor I can't do

req.models = {};
// If not in production, use the test models
if (!is_production) {
    req.session.isProd = false;
    req.session.logs.environment = "test";

    req.models.User = UserTest;
    req.models.Payment = PaymentTest;
    req.models.PayzenStatus = PayzenStatusTest;
    req.models.Transaction = TransactionTest;
    req.models.Card = CardTest;
    req.models.Doc = DocTest;
}
// Otherwise use the production models
 else {
    req.models.User = User;
    req.models.Payment = Payment;
    req.models.PayzenStatus = PayzenStatus;
    req.models.Transaction = Transaction;
    req.models.Card = Card;
    req.models.Doc = Doc;
}

If you have any idea on how ton achieve this (whatever the way, we can still perform deep changes in our code), I would be really happy to ear it.

Thanks