# subscribe(to:) Subscribe to Tor async events and return a stream of decoded messages. ``` func subscribe(to events: Set) async throws -> AsyncStream ``` ## Parameters `events` Events to subscribe to. ## Return Value An `AsyncStream` producing decoded events until the connection closes or the consumer cancels the owning task. ## Discussion Issues `SETEVENTS ` (control-spec.txt §4) with the space-joined raw values of `events`, then spawns a background `Task` that reads lines from the socket via [`readLineAsync()`](/documentation/Tor/ControlSocket/readLineAsync()), routes each `650`-status line through [`parseAsyncEvent(_:)`](/documentation/Tor/ControlProtocolParser/parseAsyncEvent(_:)), and yields the result into the returned stream. The subscription stays active for the life of the control connection. Call [`subscribe(to:)`](/documentation/Tor/TorControlClient/subscribe(to:)) with an empty `events` set to unsubscribe (Tor’s convention). > Throws: ``doc://Tor/documentation/Tor/TorError/controlProtocolError(code:message:)`` if > Tor rejects the `SETEVENTS` command (e.g. unknown event > keyword). > Important: Only one subscribe loop should read from a given > ``doc://Tor/documentation/Tor/ControlSocket`` at a time — two concurrent > ``doc://Tor/documentation/Tor/TorControlClient/subscribe(to:)`` streams on the same client will interleave > reads and fragment events. Use one ``doc://Tor/documentation/Tor/TorControlClient`` per > subscriber.