/**
 * TaskBackendRegistry — registration point for all task backend implementations.
 * Follows the same pattern as ProviderRegistry: dynamic imports, lazy registration.
 */
import type { TaskBackendName, TaskBackendFactoryFn, TaskManagerConfig, TaskBackend } from "../../types/index.js";
export declare class TaskBackendRegistry {
    private static factories;
    private static registered;
    /**
     * Register a backend factory function.
     * Can be called externally to add custom backends (e.g., "pg-boss").
     */
    static register(name: string, factory: TaskBackendFactoryFn): void;
    /**
     * Register the built-in backends (BullMQ, NodeTimeout).
     * Idempotent — safe to call multiple times.
     */
    static registerDefaults(): void;
    /**
     * Create a backend instance by name.
     */
    static create(name: TaskBackendName | string, config: TaskManagerConfig): Promise<TaskBackend>;
    /**
     * Check if a backend is registered.
     */
    static has(name: string): boolean;
    /**
     * List all registered backend names.
     */
    static getAvailable(): string[];
}