CLAUDE_CODE_PROXY_AUTHENTICATE

Updated October 13, 2026 by Alex Sorokoletov

CLAUDE_CODE_PROXY_AUTHENTICATE is a Claude Code environment variable: Carries the WWW-Authenticate challenge from the proxy into the helper. Enables challenge-response schemes by reading what the proxy actually asked for. Added between v2.1.108 and v2.1.114 and still present in v2.1.294. It is not in the official reference.

Status	Present in v2.1.294
Added	Added between v2.1.108 and v2.1.114
Category	Authentication
Official docs	Not listed

How to set it

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

export CLAUDE_CODE_PROXY_AUTHENTICATE=<value>
claude

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

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

Release notes that mention it

Claude Code v2.1.114 — Native Binary Launcher, /fewer-permission-prompts, and 20 New Environment Variables

Related variables

CLAUDE_CODE_ENABLE_PROXY_AUTH_HELPER: Set to "1" to enable the proxy auth helper subsystem.
CLAUDE_CODE_PROXY_AUTH_HELPER_TTL_MS: Cache TTL for helper-returned credentials.
ANTHROPIC_API_KEY: Primary API key for Claude API.
ANTHROPIC_AUTH_TOKEN: Alternative bearer token; takes priority over API key.
CLAUDE_AI_AUTHORIZE_URL: Authorization URL endpoint.
CLAUDE_BG_AUTH_SNAPSHOT_PATH: Path for snapshotting background session auth credentials to disk.
CLAUDE_CODE_API_KEY_FILE_DESCRIPTOR: File descriptor to read API key from.
CLAUDE_CODE_API_KEY_HELPER_TTL_MS: Cache TTL for API key helper.

Frequently asked questions

What does CLAUDE_CODE_PROXY_AUTHENTICATE do?

Carries the WWW-Authenticate challenge from the proxy into the helper. Enables challenge-response schemes by reading what the proxy actually asked for.

Which Claude Code version has CLAUDE_CODE_PROXY_AUTHENTICATE?

Added between v2.1.108 and v2.1.114 and still present in v2.1.294.

How do I set CLAUDE_CODE_PROXY_AUTHENTICATE?

Export it before starting Claude Code (export CLAUDE_CODE_PROXY_AUTHENTICATE=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.