/** Running version and, once a registry check has succeeded, the latest published version. */
export interface UpdateStatus {
    current: string;
    latest?: string;
    updateAvailable?: boolean;
}
export interface UpdateCheckOptions {
    packageName: string;
    currentVersion: string;
    /** Where the last registry result is kept between sessions. No file disables the check. */
    cacheFile?: string;
    env?: NodeJS.ProcessEnv;
    fetch?: typeof fetch;
    now?: () => number;
}
/** The check makes a network call, so it honors the telemetry opt-outs and skips CI. */
export declare function isUpdateCheckDisabled(env: NodeJS.ProcessEnv): boolean;
/** True when `latest` is a newer release than `current`. Prerelease versions never compare. */
export declare function isNewerVersion(latest: string, current: string): boolean;
/**
 * Advisory update check. Startup reads only the cached registry result, so the
 * notice never delays `initialize`; `refresh()` updates the cache in the
 * background for this session's `config_inspect` and the next session's
 * instructions.
 */
export declare class UpdateCheck {
    private readonly options;
    readonly disabled: boolean;
    private attemptedAt?;
    private cache?;
    private readonly env;
    private inflight?;
    private readonly now;
    constructor(options: UpdateCheckOptions);
    /** One instructions line when a newer version is known, otherwise undefined. */
    note(): string | undefined;
    /** Fetch the latest version when the cached result is a day old. Never rejects. */
    refresh(): Promise<void>;
    status(): UpdateStatus;
    private fetchLatest;
}