What
In auto mode, Claude Code has a model check each action before it runs. There is now a separate reason for when that check cannot happen: none of the models allowed to check this session's actions can be used here. In that case the tool is not run, and Claude is told to stop and tell you. This reason is connected to the CLAUDE_CODE_USER_DELEGATED_SESSION_DIRECT_API environment variable.
Why
On setups where only certain models may be used, auto mode can now say why it blocked an action instead of failing without a clear reason.
Names in the bundleCLAUDE_CODE_USER_DELEGATED_SESSION_DIRECT_API
One source agreesOne thing we can check says the same as this entry.
The name it cites is new in this build
New in this build: CLAUDE_CODE_USER_DELEGATED_SESSION_DIRECT_API