Sorry, totally spaced on getting back to you. So here it is:
Assuming /home/pi is where you "git clone"ed to:
create the file
/home/pi/wyoming-satellite/examples/commands/synthesize_custom.sh
with the content
#!/usr/bin/env sh
text="$(cat)"
echo "Text to speech text: ${text}"
token='LLA_TOKEN'
echo "${token}"
curlData='{
"event":"synthesize",
"satellite": "snapcast-livingroom",
"text": "'$text'"
}';
echo "$curlData" | jq '.'
curl \
-X POST \
-H "Content-Type: application/json" \
-H "Authorization: Bearer $token" \
-d "$curlData" \
https://HASS_FQDN/api/events/satellite_tts
create yourself a long-lived access token and put it for LLA_TOKEN, and fill in the FQDN of your home assistant instance for HASS_FQDN.
Then, assuming you installed on an OS using systemd, make your
/etc/systemd/system/wyoming-satellite.service
look like so:
[Unit]
Description=Wyoming Satellite
Wants=network-online.target
After=network-online.target
[Service]
Type=simple
ExecStart=/home/pi/wyoming-satellite/script/run \
--debug \
--name 'snapcast-livingroom' \
--uri 'tcp://0.0.0.0:10700' \
--mic-command 'arecord -D plughw:CARD=Device,DEV=0 -r 16000 -c
1 -f S16_LE -t raw' \
--snd-command 'aplay -D null' \
--synthesize-command 'examples/commands/synthesize_custom.sh'
WorkingDirectory=/home/pi/wyoming-satellite
Restart=always
RestartSec=1
Restart=always
[install]
Note the synthesize-command-line and sending snd to null.
Now, anytime the satellite gets send synthesized text, it should create an event in home assistant with the name of the satellite and the text to be spoken. I use this information within node-red like so:
[{"id":"c57a4a8e82851f13","type":"server-events","z":"a533baf02563f05c","name":"","server":"2452f89c.1b7828","version":3,"exposeAsEntityConfig":"","eventType":"satellite_tts","eventData":"","waitForRunning":true,"outputProperties":[{"property":"payload","propertyType":"msg","value":"","valueType":"eventData"},{"property":"topic","propertyType":"msg","value":"$outputData(\"eventData\").event_type","valueType":"jsonata"}],"x":130,"y":400,"wires":[["8a0a12e62be88756"]]},{"id":"eb18cd0b8af1bf7d","type":"api-call-service","z":"a533baf02563f05c","name":"","server":"2452f89c.1b7828","version":5,"debugenabled":false,"domain":"tts","service":"speak","areaId":[],"deviceId":[],"entityId":["tts.piper"],"data":"{\"message\":\"{{payload.event.text}}\",\"media_player_entity_id\":\"media_player.snapcast_player\"}","dataType":"json","mergeContext":"","mustacheAltTags":false,"outputProperties":[],"queue":"none","x":540,"y":400,"wires":[["50f6c0501580df66"]]},{"id":"8a0a12e62be88756","type":"switch","z":"a533baf02563f05c","name":"satellite_name","property":"payload.event.satellite","propertyType":"msg","rules":[{"t":"eq","v":"snapcast-livingroom","vt":"str"},{"t":"eq","v":"snapcast-kitchen","vt":"str"}],"checkall":"true","repair":false,"outputs":2,"x":360,"y":400,"wires":[["eb18cd0b8af1bf7d"],["b142937ea983f692"]]},{"id":"2452f89c.1b7828","type":"server","name":"Home Assistant","addon":true}]
Basically listen for the event type “satellite_tts”, route by satellite and call the tts.speak service on whatever compatible media_player you like.
Hope this helps you along 
