Developing TeamCity Plugins
TeamCity functionality can be significantly extended by custom plugins. TeamCity plugins are written in Java (any JVM language with Java invulnerability like Kotlin or Groovy can 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.
Developing Plugins Using Maven - Maven archetype supported by JetBrains
TeamCity plugin - Git, Gradle build. Supports agent and server-side plugins, and helpers to download, install a TeamCity server, tasks to deploy, start and stop the server and agent.
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
Gradle TeamCity plugin - earlier, but a bit outdated version of Gradle build for TeamCity plugins
(obsolete) Maven Archetype for TeamCity server plugin
See also a post on the very first steps for setting up the plugin development environment.