MCP_OAUTH_CALLBACK_PORT

Updated October 13, 2026 by Alex Sorokoletov

MCP_OAUTH_CALLBACK_PORT is a Claude Code environment variable: OAuth callback server port. Its release history is not tracked here. It is listed in the official reference.

Status	Present in v2.1.294
Category	Authentication
Official docs	Listed

How to set it

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

export MCP_OAUTH_CALLBACK_PORT=<value>
claude

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

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

Related variables

CLAUDE_CODE_CUSTOM_OAUTH_URL: Custom OAuth endpoint URL.
CLAUDE_CODE_OAUTH_CLIENT_ID: Custom OAuth client ID.
CLAUDE_CODE_OAUTH_REFRESH_TOKEN: OAuth refresh token.
CLAUDE_CODE_OAUTH_SCOPES: OAuth scopes for 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_SDK_HAS_OAUTH_REFRESH: Signals to the Claude Code runtime that the SDK caller has already provided an OAuth refresh token.
CLAUDE_LOCAL_OAUTH_API_BASE: Overrides the base URL for local OAuth API operations.

Frequently asked questions

What does MCP_OAUTH_CALLBACK_PORT do?

OAuth callback server port

Which Claude Code version has MCP_OAUTH_CALLBACK_PORT?

Its release history is not tracked here.

How do I set MCP_OAUTH_CALLBACK_PORT?

Export it before starting Claude Code (export MCP_OAUTH_CALLBACK_PORT=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.