What probably matters to youSection of the release
What
In the Agent SDK (the library for building your own programs on top of Claude Code), claiming an existing session now asks for that session's startup information too. This is controlled by an include_initialize option, which is true unless you set it to false.
When the reply includes this information, it replaces what the SDK client had stored from its own startup. Two earlier values, whether hooks were applied and whether plugins were applied, are kept wherever the new information leaves them unset.
Why
A program that claims a session gets up-to-date details such as the available commands and models straight away, without making a second request.
