/** True when the version carries a prerelease identifier (1.2.0-beta.2). */
export declare function isPrereleaseVersion(version: string): boolean;
/** The npm dist-tag a version belongs to: `latest` for X.Y.Z, else its channel. */
export declare function distTagForVersion(version: string): string;
export declare function isNewer(latest: string, current: string): boolean;
/**
 * The version an install should move to, or null when it is already there.
 *
 * Only ever moves forward, and never crosses from the stable line onto a
 * prerelease. Comparing installed against latest for plain inequality treats
 * "ahead of the stable line" as "out of date", which rolls a prerelease tester
 * back onto an older stable on their next update, and it would install a
 * prerelease on every stable user the moment `latest` pointed at one.
 */
export declare function resolveUpdateTarget(installed: string, latest: string): string | null;
/**
 * Kick off the version check. Returns immediately; on a positive result it
 * stashes a notice that the next tool response will pick up. Never throws.
 *
 * Set `UE_MCP_DISABLE_UPDATE_CHECK=1` to suppress entirely (offline use,
 * locked-down environments, tests).
 */
export declare function startVersionCheck(currentVersion: string): void;
/**
 * Returns the upgrade notice once if one is pending, then clears it.
 * Tool dispatchers call this on every response and prepend the result
 * to the response content blocks when non-null.
 */
export declare function consumeUpgradeNotice(): string | null;
/** Test hook. */
export declare function _resetForTests(): void;
/** Test hook. */
export declare function _setNoticeForTests(notice: string | null): void;