{"name":"CLAUDE_CODE_NO_MODEL_FALLBACK","slug":"claude-code-no-model-fallback","family":"env","title":"Environment variables","noun":"environment variable","description":"If your cloud account cannot use a model, Claude Code can step down to the next one; `CLAUDE_CODE_DISABLE_MODEL_ACCESS_FALLBACK` turns this off","description_source":"entry","described_by":{"version":"2.1.285","anchor":"third-party-model-env-vars-haiku-handled-like-opussonnet"},"presence":{"first_seen":"2.1.213","removed_in":null,"in_current_build":true,"newest_mined":"2.1.309","builds":85,"mined_builds":150,"first_cited":{"version":"2.1.213","released_at":"2026-07-17 22:26:26","spans":2}},"aliases":[],"entries":[{"version":"2.1.285","anchor":"third-party-model-env-vars-haiku-handled-like-opussonnet","heading":"Cloud accounts fall back to another model when one is not enabled","line":"If your cloud account cannot use a model, Claude Code can step down to the next one; `CLAUDE_CODE_DISABLE_MODEL_ACCESS_FALLBACK` turns this off","released_at":"2026-09-29 17:32:09","reason":"found in this entry's text"},{"version":"2.1.213","anchor":"claude-code-no-model-fallback-prevent-model-substitution","heading":"CLAUDE_CODE_NO_MODEL_FALLBACK \u2014 Prevent Model Substitution","line":null,"released_at":"2026-07-17 22:26:26","reason":"found in this entry's text"}],"entries_total":2,"docs":[],"docs_total":0,"gates":[],"related":[{"name":"CLAUDE_CODE_NO_FLICKER","slug":"claude-code-no-flicker","description":"Set to `1` to enable [fullscreen rendering](\/docs\/en\/fullscreen), a research preview that reduces flicker and keeps memory flat in long conversations. Overrides the [`tui`](\/docs\/en\/settings-reference#tui) setting; you can also switch with `\/tui fullscreen`"},{"name":"CLAUDE_CODE_NONBLOCKING_STDOUT","slug":"claude-code-nonblocking-stdout","description":"Set to `1` to write terminal output through a second non-blocking file descriptor, so a terminal that stops reading, such as a paused tmux control-mode pane or a stalled SSH connection, can't freeze Claude Code mid-session. Applies on macOS, Linux, and WSL when stdout is a terminal. Requires Claude Code v2.1.261 or later"},{"name":"CLAUDE_CODE_NONSTREAMING_TIMEOUT_RETRIES","slug":"claude-code-nonstreaming-timeout-retries","description":"When set, caps retries of a non-streaming API request that failed with a request timeout after at least 90% of its non-streaming timeout had elapsed: once that many such retries have happened, the request fails. Unset leaves these timeouts to the normal retry logic, and the cap is not applied while `CLAUDE_CODE_RETRY_WATCHDOG` is set. Digits only, minimum `0`."}],"url":"https:\/\/changelogs.core-directive.com\/reference\/env\/claude-code-no-model-fallback","family_url":"https:\/\/changelogs.core-directive.com\/reference\/env.json"}