Know when the Buildkite CLI is done or needs you, without watching its tab

You can now see when bk preflight or bk build watch finishes or needs you, without switching back to its tab. From Buildkite CLI v3.64.0, bk tells your terminal what it's doing, so a terminal that supports it can show you while you work somewhere else.

bk reports its status using OSC 7501, a draft protocol that lets programs tell the terminal whether they're working, waiting on the user, done, or failed. Rex supports it today, showing a spinner on background tabs and marking sessions that have finished or need input.

• bk build watch and bk preflight report progress as jobs finish, then whether the command finished or failed.
• bk auth login and confirmation prompts report that they're waiting on you, so a sign-in or "are you sure?" doesn't sit unnoticed behind another window.
• bk artifacts download, bk build download, and bk package push report when they've finished, or why they failed.

There's nothing to configure, and OSC 7501 is designed to be ignored by terminals that don't support it. By default, bk only sends status when stderr is a terminal, and not in CI or Buildkite jobs, so piped output, JSON output, and job logs don't change. To turn it off, set BUILDKITE_PROGRAM_STATUS=false.

OSC 7501 is still a draft, and we've adopted it early to learn whether it's useful in your workflow. Run bk update, leave a preflight running in a background tab, and tell us how it goes: which terminals and coding agents you'd like to see it in, which commands should report status next, and anything it breaks. We'll share feedback on the protocol with its authors.