Hello,

I worked on the BIP 171 and I created Cerise (github) that provides the following artifacts :

BIP-0171 specifications.
A mocked BIP-0171 compliant server available online you can use to understand the API and make calls.
A mocked BIP-0171 compliant server as a Java application you can use to develop your client application.
A mocked BIP-0171 compliant server as a Docker image you can use to develop your client application.
A BIP-0171 library to transform your application in a BIP-0171 server.
A server template project to quickly write your implementation and automatically produce your BIP-0171 server.
A collection of client libraries to call any BIP-0171 compliant server with your favorite language.

I hope it helps and if you have any suggestion on how I could help more, let me know.