Configuration Module 

When typo3/cms-lowlevel is installed, TCA_API registers a provider in the TYPO3 backend Configuration module (System → Configuration). The provider displays all loaded resource definitions as an interactive tree, which is useful for debugging your setup and verifying that definitions are loaded and parsed as expected.

TCA_API configuration tree in the TYPO3 Configuration module

What is shown 

Each resource definition is listed by its resourceName and expanded into all resolved properties. All values reflect the parsed state after ApiDefinitionLoader has normalised the raw PHP arrays — so what you see is exactly what the extension acts on at runtime.