What
When you sign in to Claude Code directly with an Anthropic account, each request carries a header, a small piece of extra information, used to attribute usage for billing. That header can now include a value saying how the work was dispatched, meaning how it was started.
The records Claude Code keeps for background jobs, which are tasks that run while you do other things, now store the same detail.
Why
Usage can be attributed to how a job was started, so the usage and billing records Anthropic receives are more detailed.