Before probing a model name against the server, the client now rejects names containing whitespace or Unicode control/format characters, guarding against spoofed or lookalike model names. This check is skipped when going through a gateway or a first-party endpoint that isn't clearly Anthropic's.
Model-name validation now rejects hidden/control characters
Model names with hidden or control characters are now rejected before being probed.
You'll noticeTier: how much it should matter to you
2Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
ModelsArea: what it touches
Bug FixesKind: in v2.1.260,
Bug FixesSection of the release