/**
 * Telemetry hooks: observation points without behavior change.
 * Used by monitoring, logging, metrics collection.
 *
 * Hooks are optional; no telemetry is added unless withTelemetry() plugin.
 */
export interface TelemetryHooks {
    onMessage?(meta: {
        type: string;
        size: number;
        ts: number;
    }): void;
    onError?(err: unknown, meta?: Record<string, unknown>): void;
    onPublish?(meta: {
        topic: string;
        type: string;
    }): void;
}
/**
 * Observer: single subscribed telemetry consumer.
 */
export interface Observer {
    onMessage?(meta: {
        type: string;
        size: number;
        ts: number;
    }): void;
    onError?(err: unknown, meta?: Record<string, unknown>): void;
    onPublish?(meta: {
        topic: string;
        type: string;
    }): void;
}
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