I noticed that steps > actions > output_url links (S3 file with build output) appear only after build is finished. Is there a way to access output during the build, in real time, as it is happening? I notice that CircleCI UI can do that, but is it possible through API?
It’s not possible to stream the step output VIA the API. This would actually be a quite expensive API as some build output can exceed 40k lines of output in a matter of seconds. The best way to watch the build output is using the UI.