CLAUDE_CODE_ULTRAREVIEW_PREFLIGHT_FIXTURE

Updated October 13, 2026 by Alex Sorokoletov

CLAUDE_CODE_ULTRAREVIEW_PREFLIGHT_FIXTURE is a Claude Code environment variable: Points to a test fixture file used during the preflight phase of UltraReview — Claude Code's automated PR review pipeline. In test and CI environments, this injects a known fixture so preflight checks (repository access, diff parsing, review scope calculation) run against deterministic data rather than live git state. Added between v2.1.104 and v2.1.107 and still present in v2.1.294. It is not in the official reference.

How to set it

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

export CLAUDE_CODE_ULTRAREVIEW_PREFLIGHT_FIXTURE=<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_FIXTURE": "<value>"
  }
}

Release notes that mention it

• Claude Code v2.1.107 — 6 New Environment Variables: Worktrees, Away Mode, and Stream Resilience

Related variables

• CLAUDE_CODE_ULTRAREVIEW_PREFLIGHT_FIXTUREA2
• CLAUDE_CODE_ULTRAREVIEW_PREFLIGHT_FIXTUREB0
• 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

All variables, searchable: Claude Code environment variables.