/**
 * Build the captions API URL for a video entity.
 *
 * Returns the HTTPS URL to the `/api/captions/[entityType]/[entityId]` endpoint
 * which serves VTT content for iOS native fullscreen subtitles.
 * Returns undefined if entity has no srt_content.
 *
 * Cache-busting hash derived from the srt_content length so iOS Safari
 * fetches fresh VTT when subtitles are regenerated (Safari aggressively caches
 * <track> src URLs even with short Cache-Control max-age).
 *
 * Lifted from hub `lib/utils/captions-url.ts`. The hub's hard-coded
 * `VideoEnabledEntityType` enum is widened to `string` here — embedders
 * pass whatever entity-type discriminator their reverse-proxied
 * `/api/captions/...` route expects.
 */
export declare function getCaptionsUrl(entityType: string, entityId: string | number, srtContent?: string | null): string | undefined;
//# sourceMappingURL=captions-url.d.ts.map