{"name":"FALLBACK_FOR_ALL_PRIMARY_MODELS","slug":"fallback-for-all-primary-models","family":"env","title":"Environment variables","noun":"environment variable","description":"Any non-empty value makes repeated `529` overloaded errors count toward the fallback threshold for every primary model; without it they count only when a fallback model is configured or for certain built-in models. After `3` such errors, the request switches to the fallback model if one is set, and otherwise (outside `IS_SANDBOX` and some other modes) fails with `Repeated 529 Overloaded errors`.","description_source":"code","described_by":{"bundle":"2.1.286","author":"claude-opus-5-5"},"presence":{"first_seen":"2.1.138","removed_in":null,"in_current_build":true,"newest_mined":"2.1.309","builds":150,"mined_builds":150,"first_cited":null},"aliases":[],"entries":[],"entries_total":0,"docs":[{"source":"claude-code","path":"env-vars","title":"Environment variables","documented":false}],"docs_total":1,"gates":[],"related":[],"url":"https:\/\/changelogs.core-directive.com\/reference\/env\/fallback-for-all-primary-models","family_url":"https:\/\/changelogs.core-directive.com\/reference\/env.json"}