export type RuntimeSchedulerPriority = "high" | "normal" | "low";
export interface RuntimeSchedulerPolicy {
    globalConcurrency: number;
    providerConcurrency: number;
    maxQueueSize: number;
    circuitBreakerFailures: number;
    circuitBreakerCooldownMs: number;
}
export interface RuntimeSchedulerTask<T> {
    provider: string;
    taskId?: string;
    role?: string;
    priority?: RuntimeSchedulerPriority;
    run: () => Promise<T>;
}
export interface RuntimeSchedulerSnapshot {
    active: number;
    queued: number;
    activeByProvider: Record<string, number>;
    queuedByProvider: Record<string, number>;
    openCircuits: Array<{
        provider: string;
        failures: number;
        openedUntil: string;
    }>;
}
export interface RuntimeSchedulerEvent {
    type: "queued" | "started" | "completed" | "failed" | "rejected_backpressure" | "rejected_circuit_open";
    provider: string;
    taskId?: string;
    role?: string;
    active: number;
    queued: number;
    timestamp: string;
    reason?: string;
}
export declare class RuntimeSchedulerError extends Error {
    readonly code: "backpressure" | "circuit_open";
    constructor(code: RuntimeSchedulerError["code"], message: string);
}
export declare class RuntimeScheduler {
    private readonly policy;
    private readonly queue;
    private readonly activeByProvider;
    private readonly circuits;
    private readonly events;
    private active;
    private nextId;
    constructor(policy: RuntimeSchedulerPolicy);
    schedule<T>(input: RuntimeSchedulerTask<T>): Promise<T>;
    snapshot(): RuntimeSchedulerSnapshot;
    drainEvents(): RuntimeSchedulerEvent[];
    private startNow;
    private drain;
    private canStart;
    private assertCircuitClosed;
    private recordFailure;
    private resetCircuit;
    private sortQueue;
    private record;
}
export declare const DEFAULT_RUNTIME_SCHEDULER_POLICY: RuntimeSchedulerPolicy;
export declare const defaultRuntimeScheduler: RuntimeScheduler;
export declare function scheduleRuntimeProviderCall<T>(input: RuntimeSchedulerTask<T>, scheduler?: RuntimeScheduler): Promise<T>;