You'll noticeTier: how much it should matter to you
2Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
SDKArea: what it touches
ImprovementsKind: in v2.1.309,
ImprovementsSection of the release
What
In print mode and SDK sessions, where Claude Code runs without its interactive screen under another program called the host, Claude Code sets up connections to MCP servers, which supply extra tools. This setup used to run only in one kind of session. It now also runs when the host has handed Claude Code its MCP listings.
In that new case the tool list is built from the declared server names, but Claude Code does not listen for sign-in renewals or for changes to a server's tool list.
Why
This changes when programs built on the SDK get MCP tools wired up for them.
