/** Does this `connect_error` message mean the server refused the bearer token? */
export declare function isTokenRefusal(message: string): boolean;
/** The pair a socket was built from. */
export interface Credentials {
    apiUrl: string;
    token: string;
}
/** Did the server come back as a different generation? */
export declare function credentialsChanged(current: Credentials, fresh: Credentials | null): boolean;
/**
 * Exponential backoff, capped.
 *
 * A restart takes seconds, so the first few re-reads should be quick; a server
 * that is down for the afternoon should not have its workspace stat-ed twice a
 * second until someone notices. Pure, so the schedule is testable without a
 * clock — `attempt` is 0-based and anything below 0 is treated as the first try.
 */
export declare function backoffMs(attempt: number): number;