When you pick a model with /model, Claude Code checks the name with the API (Anthropic's service). If that check hits a generic API error, the message now uses a cleaned-up error text, drops trailing punctuation and ends with · model not changed.
The result is also marked retryable, meaning trying again may work, when:
there is no status code
the status is 408 (timeout)
the status is 429 (too many requests)
the status is any 5xx (server-side error)
Failures that are not API errors, shown as 'Unable to validate model', are now always marked retryable.
Why
The message now states plainly that your model setting stayed as it was, and temporary problems are marked as worth retrying.
How sure we are
One source agreesOne thing we can check says the same as this entry.
Anthropic's release notes agreeFixed /model showing the raw API error JSON and request ID when the API refuses the picked model; it now shows the server's message and says…
