Developing TeamCity Plugins
TeamCity functionality can be significantly extended by a custom plugin. TeamCity plugins are written in Java (Kotlin, Groovy and JRuby can also be used), run within the TeamCity application and have access to internal entities of the TeamCity server or agent.
Aside from this documentation, please refer to the following sources:
bundled sample plugin
list of existing plugins and bundled open-source plugins
If you need more information or have a question regarding the API, please do not hesitate to post your question into TeamCity Plugins forum. Please use the search before posting to avoid possible duplication of discussions.
Consider making your plugin public and submit it to be listed on the plugins page.
Please refer to corresponding section for further details.
Plugin Quick Start
See Getting Started with Plugin Development to create your first plugin with Maven. Developing Plugins Using Maven provides more details.
There are also several approaches to create plugins provided by third parties or existing out of the main TeamCity development line:
template plugin 1, see also a blog post - Git, IDEA project
template plugin 2 - Subversion, IDEA project and Ant build, generates a plugin with custom name, see details in the readme.txt of the checkout
See also a post on the very first steps for setting up the plugin development environment.