OAuth Port Helper (mcp/oauthPort.ts)

Finds available local ports and builds redirect URIs for MCP OAuth callbacks. Use when implementing local authentication flows.

// Source: https://github.com/chauncygu/collection-claude-code-source-code | License: Apache-2.0 | Copyright You must retain, in the Source form of any Derivative Works
// Provided via justclaw.it.com; keep this notice with the code.
/**
 * OAuth redirect port helpers — extracted from auth.ts to break the
 * auth.ts ↔ xaaIdpLogin.ts circular dependency.
 */
import { createServer } from 'http'
import { getPlatform } from '../../utils/platform.js'

// Windows dynamic port range 49152-65535 is reserved
const REDIRECT_PORT_RANGE =
  getPlatform() === 'windows'
    ? { min: 39152, max: 49151 }
    : { min: 49152, max: 65535 }
const REDIRECT_PORT_FALLBACK = 3118

/**
 * Builds a redirect URI on localhost with the given port and a fixed `/callback` path.
 *
 * RFC 8252 Section 7.3 (OAuth for Nati

... (truncated -- full source via MCP)