I just released CERISE (website & github) a project with the following artifacts :
A mocked server implementation to start developing clients : https://github.com/straumat/cerise.
A live & documented API to understand and directly calls the methods : http://api.cerise.tech/docs.
Specifications of the four methods : Enumerating supported currency-pair tokens, Currency-pair information, Current exchange rate & Historical exchange rates.
16 client librairies for various langages (Java, PHP, c++, Rusty, Ruby….) : http://www.cerise.tech/#clients.
and i’m working on a template project to allow developers to quickly build a BIP171 compliant server without having to worrying about parameters validation, security, rest mechanics… will be done in september.