{"version":"2.1.287","anchor":"vertex-fallback-model-list-skips-unavailable-models-and-cove","canonical_anchor":"vertex-fallback-model-list-skips-unavailable-models-and-cove","heading":"Vertex fallback models skip ones that aren't available","tier":"notice","area":"Models","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.287\/e\/vertex-fallback-model-list-skips-unavailable-models-and-cove","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.287","markdown":"### Vertex fallback models skip ones that aren't available\n\nOn Vertex, Claude Code's list of fallback models now leaves out models that fail a check, and Opus can fall back to Sonnet\n\n**Unclear.** It is not clear what the check on each model tests.\n\n**What**\n\nWhen Claude Code runs through Google Vertex, it builds a list of fallback models to try. It now leaves out models that fail a check. For Opus, the fallback to another tier used to be added every time. It is now added only if it passes, and otherwise Sonnet models may be tried instead, depending on a setting in the request.\n\n**Why**\n\nThis changes which models Claude Code tries on Vertex.\n\n- Area: Models\n- Tier: You'll notice\n- Useful: 2\/5\n- Signal: 2\/5"}