CLAUDE_CODE_MCP_SERVE_AUTH_TOKEN

Updated October 14, 2026 by Alex Sorokoletov

CLAUDE_CODE_MCP_SERVE_AUTH_TOKEN is a Claude Code environment variable. Added in v2.1.285 and still present in v2.1.295. 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_MCP_SERVE_AUTH_TOKEN=<value>
claude

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

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

Related variables

• ANTHROPIC_AUTH_TOKEN: Alternative bearer token; takes priority over API key.
• CLAUDE_BG_AUTH_SNAPSHOT_PATH: Path for snapshotting background session auth credentials to disk.
• CLAUDE_CODE_DISABLE_AUTH_REFRESH_LOCK: Turns off the lock that coordinates a GCP or AWS credential refresh across processes.
• CLAUDE_CODE_ENABLE_PROXY_AUTH_HELPER: Set to "1" to enable the proxy auth helper subsystem.
• CLAUDE_CODE_ENABLE_TOKEN_USAGE_ATTACHMENT: Attach token usage info to messages.
• CLAUDE_CODE_IDLE_TOKEN_THRESHOLD: Works alongside CLAUDE_CODE_IDLE_THRESHOLD_MINUTES to gate when the idle-return prompt appears.
• CLAUDE_CODE_MESSAGING_TOKEN: Controls access to the local inbox for cross-session messages.
• CLAUDE_CODE_OAUTH_REFRESH_TOKEN: OAuth refresh token.

Frequently asked questions

All variables, searchable: Claude Code environment variables.