Start TeamCity Build via REST Call

bt7 is a build type identifier. Each build configuration has one. You can get the full list using the rest api as follows

http://buildserver:8111/httpAuth/app/rest/buildTypes

You can also see the build type in the url if you click any of the build configurations on your team city page. You will see a url parameter such as buildTypeId=bt7

bt7 is your buildTypeId which is a unique ID for each build configuration (job). Each project can have many build configurations.

If you click into a project and then click into a specific build configuration, your URL will be something like...

http://teacmtiyserver/viewType.html?buildTypeId=bt208

If you want to queue up a build configuration to run, just find out its buildTypeId by looking at the URL and then you can probably try running it by hitting the URL you used.