What
Claude Code can be started as a spare process with --await-claim, which leaves it parked and waiting until something claims it for a real session. While a spare is parked:
- Local MCP servers that belong to the project folder are skipped. MCP servers are outside programs that give Claude extra tools, and these are the ones started as a local process over stdio.
- A
workspace_trustmessage sent to it records nothing. It should be sent along withclaim_sessioninstead.
The code that runs the session also gains a step, takeClaimSessionStartHooks, connected to SessionStart hooks. Hooks are your own commands that Claude Code runs at certain moments, and SessionStart ones run when a session begins or resumes.
Why
If you drive parked spares yourself, sending workspace_trust before the claim no longer has any effect, so it has to travel with claim_session. Project-specific servers are also no longer started before the spare knows which project it belongs to.
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
The finding does not say exactly how `takeClaimSessionStartHooks` changes when or which `SessionStart` hooks run.