Download build output from API

Hello there, is it possible to download a build output from API? It is not currently documented, although links to download file from Web interface are of the following standard:

https://circleci.com/api/v1.1/project/:vcs-type/:username/:project/:build_num/output/:step/:container?file=true

The step for us seems to always be 13, but I’m not sure if it’s static.

Thanks! :slight_smile: