CLAUDE_CODE_EXTRA_METADATA

Updated October 13, 2026 by Alex Sorokoletov

CLAUDE_CODE_EXTRA_METADATA is a Claude Code environment variable: Passes additional metadata to API requests beyond what Claude Code includes by default. This likely attaches custom key-value pairs to the Anthropic API call headers or body — useful for enterprise deployments that need to tag requests with cost centers, team identifiers, or routing metadata for LLM gateway proxies. Added between v2.1.77 and v2.1.79 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_EXTRA_METADATA=<value>
claude

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

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

Release notes that mention it

• Claude Code v2.1.79 — 3 New Environment Variables: Subprocess Sandboxing and Startup Optimization
• Claude Code Version Tracker: Undocumented Env Vars, Feature Gates & Models

Related variables

• CLAUDE_CODE_EXTRA_BODY: Additional JSON merged into API request bodies.
• 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

All variables, searchable: Claude Code environment variables.