import type { DatabaseClient, DatabaseClientConfig } from './types.js';
/**
 * PostgreSQL database client for credential operations
 * Uses pg package (must be installed as optional dependency)
 */
export declare class PostgresClient implements DatabaseClient {
    private pool;
    private readonly config;
    constructor(config: DatabaseClientConfig);
    /**
     * Get or create connection pool
     */
    private getPool;
    testConnection(): Promise<boolean>;
    createCredential(statements: string[], username: string, password: string, expiresAt: string): Promise<void>;
    revokeCredential(statements: string[], username: string): Promise<void>;
    renewCredential(statements: string[], username: string, expiresAt: string): Promise<void>;
    close(): Promise<void>;
}
//# sourceMappingURL=postgres-client.d.ts.map