Know that relayed cross-session messages in Claude Code no longer carry user authority

Claude Code Docs·medium signal

A June 2026 Claude Code hardening change means messages relayed via SendMessage from other Claude sessions no longer carry the user's authority: receivers refuse relayed permission requests and auto mode blocks them. If you build multi-session agent setups that pass instructions between sessions, design for this — privileged actions must be authorized in the session that performs them, not delegated through a relayed message.