Can people confirm that the Lovelace path are still not working???
It’s annoying however, in that case I’m just going to edit the “states” views rather than the “lovelace” views and that will give me what I need.
If it helps anybody, the “cast.show_lovelace_view” seems to be able to recognise the names of all my “group” (non-lovelace) view names as shown below (from the configuration.yaml file).
The service should be called “cast.show_states_view”!!!
Never got it to work properly. I try it every release hoping devs actually fixed it but…nope
I notice that immediately after rebooting Home Assistant it casts Lovelace “0” number views, but after a few minutes it revert to the States “0” number views. It’s very unreliable however, it works one minute then not longer recognises the state path, then later it works again!!! Too frustating!!!
Definitely a bug somewhere in the Cast Lovelace code. I hope someone fixes it, cause Lovelace is so much nicer than States views.
It’s annoying that lovelace views can’t be displayed reliably, for now use the deprecated STATES views as an interim solution.
Details on how to configure STATES views here: https://www.home-assistant.io/integrations/group/
It’s not longer unreliable for me, it refuses to work 100% of the time now. A few versions ago, 1 time out of 5 I’d get an error, now it just doesn’t work at all.
It’s a shame as I was really excited about this feature, but this issue doesn’t seem to be getting any developer focus at all.
I’ve been programming this for the past day in YAML. It’s working 80% of the time for me, and it shows the lovelace view!!! The script I’m using to get this working is as below (note the use of single quotation marks around the view number. Did this as I couldn’t get URL path name working).
Give my YAML code a try and it’ll hopefully work for you too. I’m on Hassio v0.104.4
script:
cast_home_assistant_kitchen:
alias: Home Assistant Cast to Kitchen Display
sequence:
- service: media_player.turn_off
data:
entity_id: media_player.nest_hub_max
- delay:
seconds: 1
- service: cast.show_lovelace_view
data:
entity_id: media_player.nest_hub_max
view_path: '8'
I use a similar script to the one @sebdoan uses, for me it works around 60%. When it doesn’t work, I also get an error “unable to find a view…”.
Hope this will be fixed soon.
Having the same issue however found that if I start up https://cast.home-assistant.io/, select the target (media player) but not the ‘Source’ (the lovelace view/path), I can cast whatever I want either manually or through automations.
The https://cast.home-assistant.io/ interface also mirrors what ‘Source’ is being viewed/cast. It’s not perfect but should work ok.
I just installed 0.105.2 and I can say the latest instance is a lot less stable for this casting feature vs 0.104.3
It now only works 10% of the time.
Glad to hear I can stop beating my head against that wall and wait for a better release. I just started trying to use it for the first time.
I’m still on 0.105.2 but after several days the casting feature seems to get more solid with time. It’s about 50-70% reliable atm.
My problem is still that we need to authorize through cast.home-assistant.io, which is a manual process. I really hope that it can be automated somehow, so we just have to call the ‘cast.show_lovelace_view’ and the path needed.
I’ve never needed to do that
Then I need your expertise 
… I Simply can’t get it working without.
So without doing anything you can just go to the develop tool, services and select the ‘cast.show_lovelace_view’ and then call the entity of your nest hub using the View either by name or number?
This one here works with iOS or anything from Lovelace:
- type: custom:button-card
icon: mdi:home-assistant
name: System
tap_action:
action: call-service
service: script.casthomeassistant
- type: custom:button-card
icon: mdi:weather-cloudy
name: Weather
tap_action:
action: call-service
service: script.castweather
Script looks like this:
casthomeassistant:
alias: Cast Home Assistant
sequence:
- data:
entity_id: media_player.lounge_room_tv
view_path: home_assistant
service: cast.show_lovelace_view
castweather:
alias: Cast Weather
sequence:
- data:
entity_id: media_player.lounge_room_tv
view_path: weather
service: cast.show_lovelace_view
Other way is (only works on a cast device like chrome) You have to select the device and then you can cast to it:
- type: entities
title: Chromecast Control
show_header_toggle: false
entities:
- type: cast
name: System
view: "home_assistant"
hide_if_unavailable: false
- type: cast
name: Weather
view: "weather"
hide_if_unavailable: false
So I was excited to get home and try your approach and… voila, it worked on the very first try.
Unfortunately I kept it running over night, and this morning when I wanted to try again - same script, it “failed”. It shows the Home Assistant luvs Nabu Casa and then it says ‘Connected’. While that might be true, it still doesn’t show the lovelace view I want to cast.
So once again I have to open a Browser, head to cast.home-assistant.io and authorize and cast a lovelace view. When that is done, then I can fire your script and it will work. Also with different views - probably until the authorization is “expired” 
I was having the same problems. I gave up using the cast.show_lovelace_view service. Instead I use CATT : Using CATT and it has been working just great.
It can take 30 seconds after it shows connected to cast the card… Just leave it there and wait a bit.
I have now waited for more than one hour and it still shows the luv screen and ‘Connected’.
So there must be something else wrong.
Do I need to set up some auth_trust to leave out the authorization process with cast.home-assistant.io, could that be it or don’t you have that in your conf?
I don’t have anything in my config.