You'll noticeTier: how much it should matter to you
2Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
MCPArea: what it touches
ImprovementsKind: in v2.1.305,
ImprovementsSection of the release
What
Claude Code changed how it shows certain warnings at startup. Before, it printed them whenever the error output (stderr) was a terminal. Now it prints them to stderr when running non-interactively, such as with -p, and otherwise writes them to its log as warnings.
This covers:
The warning that a server from --mcp-config was skipped due to invalid config
The warning that a server was blocked by an enterprise policy
Some notifications
Why
Scripts that run Claude Code non-interactively still see these warnings on stderr. In an interactive session you may no longer see them printed in the terminal.
