/**
 * Check if BroadcastChannel is supported
 */
export declare function isBroadcastChannelSupported(): boolean;
/**
 * Create a reactive BroadcastChannel for cross-tab communication
 *
 * @example
 * ```ts
 * const channel = useBroadcastChannel('my-channel')
 *
 * // Subscribe to state changes
 * channel.subscribe((state) => {
 *   console.log('Last message:', state.lastMessage)
 * })
 *
 * // Post a message to all tabs
 * channel.post({ type: 'sync', data: { user: 'John' } })
 *
 * // Close when done
 * channel.close()
 * ```
 */
export declare function useBroadcastChannel<T = unknown>(channelName: string, options?: BroadcastChannelOptions): BroadcastChannelRef<T>;
/**
 * Simple one-shot broadcast to all tabs
 *
 * @example
 * ```ts
 * broadcast('app-events', { type: 'logout' })
 * ```
 */
export declare function broadcast<T = unknown>(channelName: string, message: T): void;
/**
 * Broadcast Channel Composables
 *
 * Reactive utilities for cross-tab/window communication using the BroadcastChannel API.
 */
export declare interface BroadcastChannelState<T = unknown> {
  isSupported: boolean
  isClosed: boolean
  channel: BroadcastChannel | null
  lastMessage: T | null
  error: Error | null
}
export declare interface BroadcastChannelOptions {
  onMessage?: (event: MessageEvent) => void
  onError?: (event: MessageEvent) => void
}
export declare interface BroadcastChannelRef<T = unknown> {
  get: () => BroadcastChannelState<T>
  subscribe: (fn: (state: BroadcastChannelState<T>) => void) => () => void
  post: (message: T) => void
  close: () => void
  isSupported: () => boolean
}
declare type BroadcastEventType = 'message' | 'error'
declare type BroadcastEventCallback = (data: MessageEvent) => void