SubscribeToHomeAssistantEventsAsync never sends the requested event_type #1443

The problem

IHomeAssistantConnection.SubscribeToHomeAssistantEventsAsync(eventType, cancelToken) never places the requested eventType on the outgoing subscribe_events websocket command. Every subscription that goes through the non-cached path is sent with no event_type field at all, so Home Assistant treats it as a subscription to all events.

For a non-admin user token this is fatal: Home Assistant's subscribe_events handler defaults a missing event_type to MATCH_ALL and then rejects the command as unauthorized unless the connecting user is an admin or the resolved type is on a small allow-list. A non-admin client can never obtain a working event subscription through this method, no matter which specific event type it asks for. For an admin token the call still silently over-subscribes to every event instead of the one requested.

Environment

• NetDaemon release with the issue: 26.32.0 (also present on the current main branch — no later fix)
• Last working NetDaemon release (if known): unknown; the code path appears unconditional
• Operating environment: any client using NetDaemon.Client's IHomeAssistantConnection directly or via HassModel
• Link to integration documentation on our website:

Link to or paste code that causes the issue

SubscribeToHomeAssistantEventsInternalAsync in
src/Client/NetDaemon.HassClient/Internal/HomeAssistantConnection.cs:

private async Task<IObservable<HassEvent>> SubscribeToHomeAssistantEventsInternalAsync(string? eventType,
    CancellationToken cancelToken)
{
    var combinedTokenSource = CancellationTokenSource.CreateLinkedTokenSource(
        cancelToken,
        _internalCancelSource.Token
    );

    var result = await SendCommandAndReturnHassMessageResponseAsync(new SubscribeEventCommand(),
        combinedTokenSource.Token).ConfigureAwait(false);
    ...
}

The eventType parameter is never read in the method body. SubscribeEventCommand (src/Client/NetDaemon.HassClient/Internal/HomeAssistant/Commands/SubscribeEventCommand.cs) does expose a settable EventType property with [JsonPropertyName("event_type")], but nothing ever assigns it, so it is never serialised.

Minimal reproduction:

await connection.SubscribeToHomeAssistantEventsAsync("state_changed", cancellationToken);

using a long-lived access token for a non-admin user.

Expected: the outgoing message is {"type":"subscribe_events","event_type":"state_changed",...} and Home Assistant accepts it, since state_changed is one of the event types a non-admin connection is permitted to subscribe to individually.

Actual: the outgoing message is {"type":"subscribe_events",...} with no event_type field. Home Assistant's handle_subscribe_events (homeassistant/components/websocket_api/commands.py, current main) defaults the missing field to MATCH_ALL and then raises Unauthorized because the connection is not an admin (SUBSCRIBE_ALLOWLIST only covers a fixed set of types, and MATCH_ALL is not one of them). The subscribe call fails outright for a non-admin token.

Traceback/Error logs

Home Assistant's websocket connection returns an unauthorized error result for the subscribe_events command id, and logs Refusing to allow <user> to subscribe to event __ALL__ server-side (event type resolved as MATCH_ALL).

Additional information

Home Assistant's own admin gate (for reference, homeassistant/components/websocket_api/commands.py, current main):

@decorators.websocket_command(
    {
        vol.Required("type"): "subscribe_events",
        vol.Optional("event_type", default=MATCH_ALL): str,
    }
)
def handle_subscribe_events(...):
    event_type = msg["event_type"]
    if event_type not in SUBSCRIBE_ALLOWLIST and not connection.user.is_admin:
        raise Unauthorized(user_id=connection.user.id)

A fix that sets EventType = eventType on the constructed SubscribeEventCommand in SubscribeToHomeAssistantEventsInternalAsync addresses this for both non-admin subscriptions and the unnecessary all-events over-subscription for admin users.