Under the hoodTier: how much it should matter to you
2Useful: my rating, 1 to 5
3Signal: worth watching, 1 to 5
Model RoutingArea: what it touches
Internal ChangesKind: in v2.1.268,
Internal ChangesSection of the release
What
The mechanism that lets a model id be substituted for another before a prompt is sent (driven by the CLAUDE_CODE_BREEZY_HORIZON environment variable or server-supplied config) now validates candidate model ids more precisely. It also warns distinctly when a mapping's target is the same model it's meant to replace, reporting that the mapping "maps nothing," instead of silently treating it as a no-op.
Why
This makes a misconfigured or pointless model-id mapping visible as a warning instead of failing silently, making it easier to notice when a substitution rule isn't actually doing anything.
