/**
 * Debug channel — the order-independent handshake between the SDK core and the
 * optional `@colyseus/sdk/debug` overlay.
 *
 * Publishers (a joined room in {@link Client}, a `Predict` instance) call
 * {@link publishDebug} whenever there's something the overlay could surface. If
 * the overlay is already loaded it renders immediately; if it loads LATER — the
 * usual dev-only `import("@colyseus/sdk/debug")` races the first room join — a
 * lightweight buffering stub captures the publishes so the overlay REPLAYS them
 * on install. No app-side ordering (awaiting the import) is required, and a
 * publisher that fires before the overlay loads is never dropped.
 *
 * Production (overlay never imported) stays effectively free: the stub is created
 * only on first publish, holds WeakRefs so nothing is pinned, and is bounded — an
 * app that never loads the overlay leaks neither memory nor room references.
 */
/** The receiver `@colyseus/sdk/debug` installs on `globalThis.__colyseusDebug`. */
export interface ColyseusDebugRegistry {
    publish(channel: string, handle: object): void;
}
/**
 * Publish a `handle` to the overlay `channel` (`"room"` | `"predict"` | …).
 * Prod fast path: one property read, then either a live `publish` (overlay
 * loaded) or a bounded WeakRef append (buffered for replay on install).
 */
export declare function publishDebug(channel: string, handle: object): void;
/**
 * True only when the overlay installed its LIVE receiver — NOT when
 * {@link publishDebug} merely created the pre-load buffer. Diagnostics that must
 * stay free in production (reconciler drift bookkeeping) gate on this.
 */
export declare function debugOverlayActive(): boolean;