import { Request, Response, NextFunction } from "express";
/**
 * Authentication middleware for MCP HTTP transports.
 *
 * When the MCP_AUTH_TOKEN environment variable is set, this middleware
 * requires all requests to include a matching X-MCP-AUTH header.
 *
 * This provides a simple authentication mechanism for securing MCP endpoints
 * in cluster environments where full OAuth may be overkill.
 *
 * Example usage:
 *   Server: MCP_AUTH_TOKEN=my-secret-token
 *   Client: X-MCP-AUTH: my-secret-token
 */
export declare function createAuthMiddleware(): (req: Request, res: Response, next: NextFunction) => void;
/**
 * Returns whether authentication is enabled (MCP_AUTH_TOKEN is set)
 */
export declare function isAuthEnabled(): boolean;