Sending a service request to Home Assistant

[Buxton]

I'd like to invoke in Reactor a Home Assistant service through the HA API. I use the following code in a vera plugin I wrote to send an HTTP request to Home Assistant to trigger an announcement on Alexa--using a Home Assistant Alexa integration that you can install through HACS.

myEchoDevice = "alexa_media_".. myEchoDevice
myEchoMessage = table.concat(myEchoMessage)
	
local request_body = json.encode {message = myEchoMessage, data = {["type"] = "announce",method = "all"}}

local response_body = {}
	
local theURL = 'http://'..HomeAssistantIP..':'..HomeAssistantPort..'/api/services/notify/'..myEchoDevice  
	
r, c, h = http.request {
   url = theURL,
   method = "POST",
   headers = {
   ["Content-Type"]   = "application/json",
   ["Authorization"] = "Bearer ".. HomeAssistantToken,
   ["Content-Length"] = request_body:len()
   },
source = ltn12.source.string(request_body),
sink   = ltn12.sink.table(response_body)
}

I don't see the "notify" service in the HA attributes revealed by reactor. Is there a way to access the Home Assistant API through reactor, or do I need to use HTTP requests to initiate services.

[toggledbits]

One of the big gaps in the Home Assistant API is that it doesn't expose what services are available on every entity. I don't think it actually knows. But, you can tell MSR that an entity uses a particular service. You should have a file called local_hass_devices.yaml in your config subdirectory. If not, it's no trouble to just add it. There's also a default version in dist-config you can copy. To that file, in the entities section, just add entry for the entity using its canonical ID, and the services you want to add to it. Here's a sample file to give you the general idea:

# This file has local definitions/overrides for HomeAssistant devices.
---
entities:
  # Entry shows how an entity can have a service added and its name forced
  "hass>sensor_connected_clients":
    name: "WebSocket Clients"
    services:
      - homeassistant
  # This media player is a Sonos device, so it supports TTS
  "hass>media_player_portable":
    services:
      - tts
  # This media player is a Sonos device, so it supports TTS
  "hass>media_player_media_room":
    services:
      - tts
  #
  "hass>switch_power_switch":
    services:
      - zwave_js

Or, to do it the simplest way possible, there's a call_service action on the system entity for the HassController instance.