/**
 * Session service handles authentication and session lifecycle.
 */
import { ServiceContext } from './service-context';
import { Session } from '../session';
/**
 * Session service for authentication and session management.
 */
export declare class SessionService {
    private ctx;
    constructor(ctx: ServiceContext);
    /**
     * Authenticate the user and create a session.
     */
    login(username: string, password: string, defaultGraph: string): Promise<Session>;
    /**
     * Terminate the current session.
     */
    logout(): Promise<void>;
    /**
     * Check the connection and return the latency in nanoseconds.
     */
    ping(): Promise<number>;
}