This document describes what you need to know when working on the MySQL 8.0 code. To track or contribute to MySQL development, follow the instructions in Installing MySQL Using a Development Source Tree. If you are interested in MySQL internals, you should also join the MySQL Community Slack. Feel free to ask questions about the code and to send patches that you would like to contribute to the MySQL project!
The MySQL source code contains internal documentation written using Doxygen. This documentation is useful for understanding how MySQL works from a developer perspective. The generated Doxygen content is available at https://dev.mysql.com/doc/index-other.html. It is also possible to generate this content locally from a MySQL source distribution using the instructions at Generating MySQL Doxygen Documentation Content.