CLAUDE_CODE_ULTRAREVIEW_PREFLIGHT_FIXTUREB0

Updated October 14, 2026 by Alex Sorokoletov

CLAUDE_CODE_ULTRAREVIEW_PREFLIGHT_FIXTUREB0 is a Claude Code environment variable. Removed between v2.1.229 and v2.1.234, so current releases ignore it. It is not in the official reference.

Status	Removed between v2.1.229 and v2.1.234
Added	Added in v2.1.229
Category	Other
Official docs	Not listed

How to set it

For one session, export it in the shell that starts Claude Code:

export CLAUDE_CODE_ULTRAREVIEW_PREFLIGHT_FIXTUREB0=<value>
claude

To apply it to every session, add it to the env object of a settings file:

// ~/.claude/settings.json
{
  "env": {
    "CLAUDE_CODE_ULTRAREVIEW_PREFLIGHT_FIXTUREB0": "<value>"
  }
}

Related variables

CLAUDE_CODE_ULTRAREVIEW_PREFLIGHT_FIXTURE: Points to a test fixture file used during the preflight phase of UltraReview — Claude Code's automated PR review pipeline.
CLAUDE_CODE_ULTRAREVIEW_PREFLIGHT_FIXTUREA2
CLAUDE_CODE_ULTRAREVIEW_QUOTA_FIXTURE
ANTHROPIC_BETAS: Comma-separated beta feature headers.
ANTHROPIC_CUSTOM_HEADERS: Custom HTTP headers (newline-separated Key: Value).
ANTHROPIC_FEDERATION_RULE_ID
ANTHROPIC_ORGANIZATION_ID
ANTHROPIC_WORKSPACE_ID

Frequently asked questions

Which Claude Code version has CLAUDE_CODE_ULTRAREVIEW_PREFLIGHT_FIXTUREB0?

Removed between v2.1.229 and v2.1.234, so current releases ignore it.

How do I set CLAUDE_CODE_ULTRAREVIEW_PREFLIGHT_FIXTUREB0?

Export it before starting Claude Code (export CLAUDE_CODE_ULTRAREVIEW_PREFLIGHT_FIXTUREB0=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.