A background agent is a helper Claude runs alongside your main conversation. When one is resumed, Claude Code no longer sets replHydration: { kind: "resume" } in the stream override it passes along.
Why
This is an internal change to how background agents are resumed. The finding does not show a visible effect.
How sure we are
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubtThe finding does not say what dropping `replHydration` changes when an agent resumes.
