Welcome to the official TYPO3 API Documentation
TYPO3 source code is well documented and allows you to understand many internals by browsing through the various classes and methods.
TYPO3 main/v15-dev API
Automatically generated API from the main branch of TYPO3.
TYPO3 v14.3 LTS API
Automatically generated API from the 14.3 branch of TYPO3.
TYPO3 v13.4 LTS API
Automatically generated API from the 13.4 branch of TYPO3.