import { SdkTransport } from "@onflow/typedefs";
/**
 * Get the SDK transport object, either from the provided override or from the global config.
 *
 * The transport object handles communication with Flow Access Nodes, including sending transactions,
 * executing scripts, and managing subscriptions. This function resolves the transport configuration
 * from various sources with the following priority order:
 * 1. Provided override parameters
 * 2. Global SDK configuration
 * 3. Default HTTP transport
 *
 * @param override Override default configuration with custom transport or send function
 * @param override.send Custom send function for backwards compatibility with legacy configurations
 * @param override.transport Complete transport object with both send and subscribe capabilities
 * @returns The resolved SDK transport object with send and subscribe methods
 *
 * @throws {Error} When both transport and send options are provided simultaneously
 * @throws {SubscriptionsNotSupportedError} When attempting to subscribe using a legacy send-only transport
 *
 * @example
 * import * as fcl from "@onflow/fcl";
 * import { httpTransport } from "@onflow/transport-http";
 *
 * // Get default transport (usually HTTP transport)
 * const defaultTransport = await fcl.getTransport();
 *
 * // Override with custom transport
 * const customTransport = await fcl.getTransport({
 *   transport: httpTransport({
 *     accessNode: "https://rest-mainnet.onflow.org",
 *     timeout: 10000
 *   })
 * });
 */
export declare function getGlobalTransport(cfg: Record<string, any>): SdkTransport;