Documentation on the FunnelFlux APIs can be found directly from your tracker via the knowledgebase menu, i.e.
Note: accessing from this area will load the documents from within your FunnelFlux installation, which allows direct execution and testing of your tracker's API.
You can separately view these documents below:
API Documentation for Statistics:
API Documentation for Data:
Note: The new API has a FunnelFlux version requirement of 1.6+. If your API request is still using the old API, then it will still work with FunnelFlux version 1.6+