CLAUDE_CODE_MESSAGING_TOKEN

Updated October 13, 2026 by Alex Sorokoletov

CLAUDE_CODE_MESSAGING_TOKEN is a Claude Code environment variable: Controls access to the local inbox for cross-session messages. A sender opens the socket named in CLAUDE_CODE_MESSAGING_SOCKET and sends this token first. If the token cannot reach peers, the inbox does not start. An inbox that no peer can reach does not run. Added in v2.1.228 and still present in v2.1.294. It is listed in the official reference.

How to set it

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

export CLAUDE_CODE_MESSAGING_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_MESSAGING_TOKEN": "<value>"
  }
}

Release notes that mention it

• Claude Code Version Tracker: Undocumented Env Vars, Feature Gates & Models
• claude-code-env-vars-v2-1-228

Related variables

• ANTHROPIC_AUTH_TOKEN: Alternative bearer token; takes priority over API key.
• 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_OAUTH_REFRESH_TOKEN: OAuth refresh token.
• CLAUDE_CODE_OAUTH_TOKEN: Pre-configured OAuth access token.
• CLAUDE_CODE_OAUTH_TOKEN_FILE_DESCRIPTOR: File descriptor to read OAuth token from.
• CLAUDE_CODE_RESUME_TOKEN_THRESHOLD: Sets the token count threshold for session resume eligibility.
• CLAUDE_CODE_SESSION_ACCESS_TOKEN: Session-scoped access token.

Frequently asked questions

All variables, searchable: Claude Code environment variables.