Unclear What handoffRelay is used for, or what user-facing effect it has, isn't established by the evidence.
What
When Claude Code starts a headless session (used by the SDK or CLI harness), the internal options object built for it — which already includes things like thinkingConfig, jsonSchema, initialMessages, and agents — now also includes a handoffRelay field. It's only set when both an internal value and a matching internal flag are present; otherwise it's left unset.
Why
The finding doesn't say what consumes handoffRelay or what user-visible behavior it enables, so it's not clear yet what this changes in practice.
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
What `handoffRelay` is used for, or what user-facing effect it has, isn't established by the evidence.