Build Artifact
Build artifacts are files produced by a build. Typically, these include distribution packages, WAR files, reports, log files, and so on. When creating a build configuration, you specify the paths to the artifacts of your build on the Configuring General Settings page.
Artifacts Storage
TeamCity contains an integrated lightweight builds artifact repository.
Upon the build finish, TeamCity searches for artifacts in the build checkout directory according to the specified artifact path or path patterns. The matching files are then uploaded ("published") to the TeamCity server, where they become available for downloading through the web UI or can be used in other builds using artifact dependencies. You can choose when to publish artifacts: for all completed builds, only for successful builds, or for all builds, even the interrupted ones.
To download artifacts of a build, go to the Artifacts tab of the build results page or use the artifacts icon 
available on the project or build configuration Overview page and on the TeamCity pages that list the builds.
If the artifacts are stored as an archive, you can still browse files inside this archive.
You can automate artifacts downloading as described in the Patterns For Accessing Build Artifacts section.
Build artifacts can also be uploaded to the server while the build is still running. To instruct TeamCity to upload the artifacts, the build script should be modified to send service messages.
Hidden Artifacts
In addition to user-defined artifacts, TeamCity also generates and publishes some artifacts for internal purposes. These are called hidden artifacts.
For example, for Maven builds, TeamCity creates the maven-build-info.xml file that contains Maven-specific data collected during the build. The content of the file is then used to visualize the Maven data on the Maven Build Info tab in the build results.
Hidden artifacts are placed under the
.teamcitydirectory in the root of the build artifacts.Hidden artifacts are not listed on the Artifacts tab of the build results by default. However, below the list of the artifacts there's a link that allows you to view hidden artifacts if any. When hidden artifacts are displayed, clicking the Download all link will result in downloading all artifacts including hidden ones.
Artifacts dependencies do not download hidden artifacts unless they explicitly have
.teamcityin the pattern.Hidden artifacts are not deleted by the artifacts clean-up unless
.teamcityis explicitly specified in the pattern.
You can configure publishing some builds artifacts under the .teamcity directory to make them hidden.
Some of the hidden artifacts are:
maven-build-info.xml.gz— Maven build data. Used to display data on the Maven Build Info build's tab.propertiesdirectory — holds properties calculated for the build on the agent. There are properties actual before the build and after the build. These are displayed on the build Properties tab..NETCoverage— raw .NET coverage data (for example, used to open dotCover data in VS add-in).coverage_idea— raw IntelliJ IDEA coverage data (for example, used to open coverage in IDEA).
Artifacts Cache on Agent
All artifacts published by a build are stored in the agent's artifacts cache in the <Build Agent home>\system\.artifacts_cache directory, which helps speed up artifact dependencies in some cases.
However, depending on the size of artifacts, clean-up, and other settings, artifacts caching may cause low disk space on the agent. You can configure storing published artifacts in the agent cache.