ANTHROPIC_CUSTOM_HEADERS

Updated October 13, 2026 by Alex Sorokoletov

ANTHROPIC_CUSTOM_HEADERS is a Claude Code environment variable: Custom HTTP headers (newline-separated Key: Value). Its release history is not tracked here. It is listed in the official reference.

Status	Present in v2.1.294
Category	Other
Official docs	Listed

How to set it

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

export ANTHROPIC_CUSTOM_HEADERS=<value>
claude

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

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

Related variables

ANTHROPIC_BETAS: Comma-separated beta feature headers.
ANTHROPIC_FEDERATION_RULE_ID
ANTHROPIC_ORGANIZATION_ID
ANTHROPIC_WORKSPACE_ID
CLAUDE_CODE_GATEWAY_HINT_HEADERS
BETA_TRACING_ENDPOINT: Custom endpoint for beta tracing.
CLAUDE_AFK_COUNTDOWN_MS
CLAUDE_AI_ORIGIN: Overrides the base URL for Claude AI authentication endpoints.

Frequently asked questions

What does ANTHROPIC_CUSTOM_HEADERS do?

Custom HTTP headers (newline-separated Key: Value)

Which Claude Code version has ANTHROPIC_CUSTOM_HEADERS?

Its release history is not tracked here.

How do I set ANTHROPIC_CUSTOM_HEADERS?

Export it before starting Claude Code (export ANTHROPIC_CUSTOM_HEADERS=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.