/**
 * Exponential backoff with jitter for stream reconnection.
 */
export interface BackoffConfig {
    /** Initial delay in milliseconds (default: 500) */
    initialDelayMs: number;
    /** Maximum delay in milliseconds (default: 30000) */
    maxDelayMs: number;
    /** Multiplier for exponential growth (default: 2) */
    multiplier: number;
    /** Random jitter fraction 0–1 added on top (default: 0.2) */
    jitterFraction: number;
}
export declare const DEFAULT_BACKOFF: BackoffConfig;
/**
 * Calculate the next backoff delay for a given attempt number.
 * Attempt 0 = first retry.
 */
export declare function nextDelay(attempt: number, config?: BackoffConfig): number;
export declare const GRPC_STATUS: {
    readonly CANCELLED: 1;
    readonly DEADLINE_EXCEEDED: 4;
    readonly PERMISSION_DENIED: 7;
    readonly RESOURCE_EXHAUSTED: 8;
    readonly UNIMPLEMENTED: 12;
    readonly UNAVAILABLE: 14;
};
/** Transient errors that should be retried with backoff */
export declare function isTransientError(code: number | undefined): boolean;
/** Fatal errors that indicate permanent failure — stop retrying */
export declare function isFatalError(code: number | undefined): boolean;