Claude Code 2.1.235 to 2.1.237: Concise style, ANTHROPIC_DEFAULT_MODEL, and spell checking

Three releases in three days. The biggest difference in daily work comes from the built-in Concise output style, but there is also a long-requested variable for the default model and one security fix worth not skipping.

Version 2.1.237 and the Concise style

In this style Claude leads with the result and skips the preamble and the recap of what it just did, while doing the work just as thoroughly. You pick it under Output style in /config.

Prompt caching was also fixed for sessions that go through a proxy gateway or a custom base URL. If you run Claude through your own proxy, that is a direct saving, because the cache used to fall away and the bill was higher than it should have been.

Version 2.1.236: default model, notification, and the sandbox

• ANTHROPIC_DEFAULT_MODEL sets the model new sessions start on. A manual choice with /model still wins and survives a restart, which is how it differs from the older ANTHROPIC_MODEL variable.
• The notify_when_idle option in cross-session messaging asks another session on the same machine to report the next time it is idle. It fires once, requires explicit consent, involves no polling, and works on macOS and Linux.
• In the macOS sandbox, deny-read rules by pattern such as **/.env now take precedence inside allowed areas, cover the contents of matched folders, and cannot be bypassed by renaming a file.

Version 2.1.235 and spell checking

Misspelled words are now optionally underlined in the input box as you type, through an installed aspell, hunspell, or ispell. A bug that invalidated the entire prompt cache when the language server disconnected or reconnected mid-session was also fixed.