# BlockchainSync.Updates.AsyncIterator Single-consumer iterator over a running sync. ``` struct AsyncIterator ``` ## Overview Owns the `AsyncStream` backing the sync and the `Task` that drives the producer. Cleanup (`Task.cancel()` + [`interrupt()`](/documentation/BitcoinKernel/Context/interrupt())) fires via `AsyncStream.onTermination` when the iterator goes out of scope or the stream finishes.