There is a step-by-step tutorial on using the TCMP SDK to develop a command-line utility in NodeJS here.
TCMP Tappy SDK
The TCMP Tappy SDK is highly modular and designed to work in both Chrome packaged app environments as well as in NodeJS utilities. If you wish to use most fundamental version of the SDK, it is best to start from documentation for the core TCMP Tappy driver on GitHub.
In order to limit unnecessary dependencies, the core Tappy TCMP library only provides the basic fundamentals of communicating with a TCMP Tappy. For most applications, it would be best to start from the abstraction wrapper library. This library has all the capabilities of the core SDK, but simplifies performing common operations by adding several convenience functions.
Tappy Classic SDK
As the Tappy Classic protocol has been deprecated, the Classic SDK is deprecated as well. This SDK only supports usage in Chrome packaged apps.