Follow a build publish_app started: its state, the log it has written so far, and, once it succeeds, the release it produced, the URL that serves it, and its deploy: deploy_state and every process with the release it targets and the release it runs. Poll every ten to fifteen seconds until deploy_state is up, crashed, or refused, or the build failed; most deploys finish within five minutes. checking means the release waits for the organization's release policies: follow evaluation.id with get_evaluation and wait_seconds 20. refused means it will not go live; get_evaluation says why. starting means a process is still booting the release. crashed means a process kept failing on it and was stopped: a web process that had a running release keeps serving it, so a working URL does not prove the new release is live, and other crashed processes are down until fixed. Its state_reason says why. When it is the app's own output, usually a start command that exited or a server not listening on $PORT, fix the code and publish again; when it names a platform or configuration failure, fix that or publish again. A failed build's log is where the reason is, usually a missing dependency. Requires connecting a Valet account.