CLAUDE_CODE_DISABLE_MODEL_ACCESS_FALLBACK
Updated by Alex Sorokoletov
CLAUDE_CODE_DISABLE_MODEL_ACCESS_FALLBACK is a Claude Code environment variable: Present in the v2.1.285 build and absent from that release's notes. Added in v2.1.285 and still present in v2.1.294. It is listed in the official reference.
| Status | Present in v2.1.294 |
|---|---|
| Added | Added in v2.1.285 |
| Category | Models and thinking |
| Official docs | Listed |
How to set it
For one session, export it in the shell that starts Claude Code:
export CLAUDE_CODE_DISABLE_MODEL_ACCESS_FALLBACK=<value>
claudeTo apply it to every session, add it to the env object of a settings file:
// ~/.claude/settings.json
{
"env": {
"CLAUDE_CODE_DISABLE_MODEL_ACCESS_FALLBACK": "<value>"
}
}Release notes that mention it
- Claude Code Version Tracker: Undocumented Env Vars, Feature Gates & Models
- claude-code-env-vars-v2-1-285
Related variables
CLAUDE_CODE_DISABLE_LEGACY_MODEL_REMAPCLAUDE_CODE_DISABLE_UNKNOWN_MODEL_WINDOW_ENFORCEMENTCLAUDE_CODE_NO_MODEL_FALLBACK: When set, the availability chain collapses to [primary]: buildAvailabilityFallbackChain() returns only the model you selected, and a tripwire error fires if any path still attempts a fallback pivot ("a model-fallback pivot was attempted while the no-fallback guarantee is active … this branch should be unreachable").CLAUDE_CODE_SKIP_MODEL_ACCESS_MEMORYANTHROPIC_CUSTOM_MODEL_OPTIONANTHROPIC_CUSTOM_MODEL_OPTION_DESCRIPTIONANTHROPIC_CUSTOM_MODEL_OPTION_NAMEANTHROPIC_CUSTOM_MODEL_OPTION_SUPPORTED_CAPABILITIES
Frequently asked questions
What does CLAUDE_CODE_DISABLE_MODEL_ACCESS_FALLBACK do?
Present in the v2.1.285 build and absent from that release's notes.
Which Claude Code version has CLAUDE_CODE_DISABLE_MODEL_ACCESS_FALLBACK?
Added in v2.1.285 and still present in v2.1.294.
How do I set CLAUDE_CODE_DISABLE_MODEL_ACCESS_FALLBACK?
Export it before starting Claude Code (export CLAUDE_CODE_DISABLE_MODEL_ACCESS_FALLBACK=value), or add it to the "env" object in ~/.claude/settings.json to apply it to every session.
All variables, searchable: Claude Code environment variables.