/**
 * API transport — executes queries against the real Lightdash async metrics endpoint.
 *
 * Flow:
 * 1. POST /api/v2/projects/{projectUuid}/query/metric-query
 *    → returns { queryUuid }
 * 2. Poll GET /api/v2/projects/{projectUuid}/query/{queryUuid}
 *    → returns results when status is 'ready'
 */
import type { Column, LightdashClientConfig, Transport } from './types';
/**
 * A function that performs HTTP requests and returns parsed JSON results.
 * The default implementation uses `Authorization: ApiKey` header.
 * Supply a custom adapter to use session cookies or other auth mechanisms.
 */
export type FetchAdapter = <T>(method: string, path: string, body?: unknown, metadata?: Record<string, unknown>) => Promise<T>;
export declare function mapColumnType(type: string): Column['type'];
/**
 * Creates a transport that executes queries via the Lightdash REST API.
 *
 * @param config - Client configuration (projectUuid is required; apiKey/baseUrl
 *   are used by the default fetch adapter but ignored when a custom adapter is provided)
 * @param adapter - Optional custom fetch adapter. When omitted, uses the default
 *   adapter that authenticates via `Authorization: ApiKey` header.
 */
export declare function createApiTransport(config: LightdashClientConfig, adapter?: FetchAdapter): Transport;