CLAUDE_CODE_GAULT_KESTREL

Updated October 14, 2026 by Alex Sorokoletov

CLAUDE_CODE_GAULT_KESTREL is a Claude Code environment variable. Removed between v2.1.269 and v2.1.283, so current releases ignore it. It is not in the official reference.

Status	Removed between v2.1.269 and v2.1.283
Added	Added between v2.1.215 and v2.1.217
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_GAULT_KESTREL=<value>
claude

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

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

Related variables

CLAUDE_CODE_NANKEEN_KESTREL: Windows-only sandbox gate.
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
BETA_TRACING_ENDPOINT: Custom endpoint for beta tracing.
CLAUDE_AFK_COUNTDOWN_MS

Frequently asked questions

Which Claude Code version has CLAUDE_CODE_GAULT_KESTREL?

Removed between v2.1.269 and v2.1.283, so current releases ignore it.

How do I set CLAUDE_CODE_GAULT_KESTREL?

Export it before starting Claude Code (export CLAUDE_CODE_GAULT_KESTREL=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.