/**
 * @file Upstream janus release asset-name mapping per `platform-arch`. janus
 *   publishes per-platform tarballs under
 *   https://github.com/divmain/janus/releases/download/v<X.Y.Z>/. At v1.22.0
 *   only darwin-arm64 is shipped; this map will expand as upstream adds builds.
 *   Callers receive `undefined` for unsupported platforms — surface that as an
 *   actionable "janus is mac-arm64 only" error rather than blindly fetching a
 *   404.
 */
export interface JanusAssetEntry {
    /**
     * Full asset filename (version-free; the helper interpolates the tag).
     */
    readonly asset: string;
}
export declare const JANUS_ASSET_MAP: Readonly<Record<string, JanusAssetEntry>>;
export declare function getJanusAssetEntry(platformArch: string): JanusAssetEntry | undefined;
export interface JanusDownloadOptions {
    /**
     * Janus release version, e.g. `'1.22.0'` (no `v` prefix; the helper prepends
     * it for the release tag).
     */
    version: string;
    /**
     * Fleet platform-arch token — looked up in `JANUS_ASSET_MAP`. Returns
     * `undefined` for any platform-arch janus doesn't ship a build for.
     */
    platformArch: string;
}
/**
 * Build the GitHub release-asset download URL for an upstream janus binary.
 * Returns `undefined` when no entry exists for the requested platform-arch.
 *
 * Reference: https://github.com/divmain/janus/releases.
 */
export declare function getJanusDownloadUrl(opts: JanusDownloadOptions): string | undefined;
