The Rachio3e does not support seem to support HomeKit.
Rachio 3e sprinkler controller arrives with lower price, pared down specs.
Also there is no mention of HomeKit on the Rachio3e product product page even though other smart home platforms are listed.
See also this discussion which seems to confirm it does not support HomeKit.
The fact that the Rachio 3 (non E version) does support HomeKit is no help to me because the Rachio 3 is illegal to use in Europe. This is mainly down to the transmitter for the now discontinued Wireless Flow Meter. It is less clear how badly illegal the 3e is but certainly Rachio have made zero effort to make it legal. This is my point, being a new product and being that Rachio are aware of the issues they had the opportunity to design it so it could have been legal.
Rachio have not been encouraging sales to Europe in that their own web store does not seem to list Europe as a shipping destination and there is no marketing also encouraging this but neither are they warning people and the responses to people in the forums and even the fact there is specifically an International Users forum as per this very one we are posting in is clearly leading to people breaking the law with the Rachio product.