You'll noticeTier: how much it should matter to you
1Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
HooksArea: what it touches
ImprovementsKind: in v2.1.290,
ImprovementsSection of the release
What
A SessionStart hook is a command you or a plugin set up to run when a session begins or resumes. Its output is added to the conversation. When that output arrives late, Claude Code now holds it while a tool call is still open, instead of adding it straight away. A tool call is one action Claude takes, such as running a command. If the output cannot be added at all, Claude Code logs that it was dropped.
Why
Adding text between a tool call and its result could break the order the conversation depends on. Waiting keeps each tool call and its result together.
