The SBE3 protocol is based on the Simple Binary Encoding (here). You can either use the API package OR write directly to the SBE schema and documentation to produce your own high-speed implementation.
The SBE3 API does not currently support RFQ/RFS flows. Only the 3.14.0 APIs and the upcoming Whisperer Enterprise support this feature. This version is good for market data and simple taker execution.
The trading interface of the Classic 3.14.0 SBE protocol should not be used. It is best practice to use Classic MFAPI for trading.
SBE3 Schema
Further detail is provided in the following page(s):
Overview
Content Tools